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Białas M, Mirończuk MM, Mańdziuk J. Leveraging spiking neural networks for topic modeling. Neural Netw 2024; 178:106494. [PMID: 38972130 DOI: 10.1016/j.neunet.2024.106494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/06/2024] [Accepted: 06/25/2024] [Indexed: 07/09/2024]
Abstract
This article investigates the application of spiking neural networks (SNNs) to the problem of topic modeling (TM): the identification of significant groups of words that represent human-understandable topics in large sets of documents. Our research is based on the hypothesis that an SNN that implements the Hebbian learning paradigm is capable of becoming specialized in the detection of statistically significant word patterns in the presence of adequately tailored sequential input. To support this hypothesis, we propose a novel spiking topic model (STM) that transforms text into a sequence of spikes and uses that sequence to train single-layer SNNs. In STM, each SNN neuron represents one topic, and each of the neuron's weights corresponds to one word. STM synaptic connections are modified according to spike-timing-dependent plasticity; after training, the neurons' strongest weights are interpreted as the words that represent topics. We compare the performance of STM with four other TM methods Latent Dirichlet Allocation (LDA), Biterm Topic Model (BTM), Embedding Topic Model (ETM) and BERTopic on three datasets: 20Newsgroups, BBC news, and AG news. The results demonstrate that STM can discover high-quality topics and successfully compete with comparative classical methods. This sheds new light on the possibility of the adaptation of SNN models in unsupervised natural language processing.
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Affiliation(s)
- Marcin Białas
- National Information Processing Institute, al. Niepodległości 188b, 00-608, Warsaw, Poland.
| | | | - Jacek Mańdziuk
- Faculty of Mathematics and Information Science, Warsaw University of Technology, Warsaw, Poland.
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2
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Walters JM, Noblet HA, Chung HJ. An emerging role of STriatal-Enriched protein tyrosine Phosphatase in hyperexcitability-associated brain disorders. Neurobiol Dis 2024; 200:106641. [PMID: 39159894 DOI: 10.1016/j.nbd.2024.106641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 08/15/2024] [Accepted: 08/16/2024] [Indexed: 08/21/2024] Open
Abstract
STriatal-Enriched protein tyrosine Phosphatase (STEP) is a brain-specific tyrosine phosphatase that is associated with numerous neurological and neuropsychiatric disorders. STEP dephosphorylates and inactivates various kinases and phosphatases critical for neuronal function and health including Fyn, Pyk2, ERK1/2, p38, and PTPα. Importantly, STEP dephosphorylates NMDA and AMPA receptors, two major glutamate receptors that mediate fast excitatory synaptic transmission. This STEP-mediated dephosphorylation leads to their internalization and inhibits both Hebbian synaptic potentiation and homeostatic synaptic scaling. Hence, STEP has been widely accepted to weaken excitatory synaptic strength. However, emerging evidence implicates a novel role of STEP in neuronal hyperexcitability and seizure disorders. Genetic deletion and pharmacological blockade of STEP reduces seizure susceptibility in acute seizure mouse models and audiogenic seizures in a mouse model of Fragile X syndrome. Pharmacologic inhibition of STEP also decreases hippocampal activity and neuronal intrinsic excitability. Here, we will highlight the divergent roles of STEP in excitatory synaptic transmission and neuronal intrinsic excitability, present the potential underlying mechanisms, and discuss their impact on STEP-associated neurologic and neuropsychiatric disorders.
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Affiliation(s)
- Jennifer M Walters
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hayden A Noblet
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hee Jung Chung
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Dept. of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Institute of Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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3
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Cavanaugh BL, Milstein ML, Boucher RC, Tan SX, Hanna MW, Seidel A, Frederiksen R, Saunders TL, Sampath AP, Mitton KP, Zhang DQ, Goldberg AFX. A new mouse model for PRPH2 pattern dystrophy exhibits functional compensation prior and subsequent to retinal degeneration. Hum Mol Genet 2024:ddae128. [PMID: 39231530 DOI: 10.1093/hmg/ddae128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 07/19/2024] [Accepted: 08/21/2024] [Indexed: 09/06/2024] Open
Abstract
Mutations in PRPH2 are a relatively common cause of sight-robbing inherited retinal degenerations (IRDs). Peripherin-2 (PRPH2) is a photoreceptor-specific tetraspanin protein that structures the disk rim membranes of rod and cone outer segment (OS) organelles, and is required for OS morphogenesis. PRPH2 is noteworthy for its broad spectrum of disease phenotypes; both inter- and intra-familial heterogeneity have been widely observed and this variability in disease expression and penetrance confounds efforts to understand genotype-phenotype correlations and pathophysiology. Here we report the generation and initial characterization of a gene-edited animal model for PRPH2 disease associated with a nonsense mutation (c.1095:C>A, p.Y285X), which is predicted to truncate the peripherin-2 C-terminal domain. Young (P21) Prph2Y285X/WT mice developed near-normal photoreceptor numbers; however, OS membrane architecture was disrupted, OS protein levels were reduced, and in vivo and ex vivo electroretinography (ERG) analyses found that rod and cone photoreceptor function were each severely reduced. Interestingly, ERG studies also revealed that rod-mediated downstream signaling (b-waves) were functionally compensated in the young animals. This resiliency in retinal function was retained at P90, by which time substantial IRD-related photoreceptor loss had occurred. Altogether, the current studies validate a new mouse model for investigating PRPH2 disease pathophysiology, and demonstrate that rod and cone photoreceptor function and structure are each directly and substantially impaired by the Y285X mutation. They also reveal that Prph2 mutations can induce a functional compensation that resembles homeostatic plasticity, which can stabilize rod-derived signaling, and potentially dampen retinal dysfunction during some PRPH2-associated IRDs.
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Affiliation(s)
| | - Michelle L Milstein
- Eye Research Institute, Oakland University, Rochester, MI 48309, United States
| | - R Casey Boucher
- Eye Research Institute, Oakland University, Rochester, MI 48309, United States
| | - Sharon X Tan
- Eye Research Institute, Oakland University, Rochester, MI 48309, United States
| | - Mario W Hanna
- Eye Research Institute, Oakland University, Rochester, MI 48309, United States
| | - Adam Seidel
- Eye Research Institute, Oakland University, Rochester, MI 48309, United States
| | - Rikard Frederiksen
- Stein Eye Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-7000, United States
| | - Thomas L Saunders
- Trangsgenic Animal Model Core, Biomedical Research Core Facilities, Division of Genetic Medicine, University of Michigan, Ann Arbor, MI 41809, United States
| | - Alapakkam P Sampath
- Stein Eye Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-7000, United States
| | - Kenneth P Mitton
- Eye Research Institute, Oakland University, Rochester, MI 48309, United States
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, United States
| | - Dao-Qi Zhang
- Eye Research Institute, Oakland University, Rochester, MI 48309, United States
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, United States
| | - Andrew F X Goldberg
- Eye Research Institute, Oakland University, Rochester, MI 48309, United States
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, United States
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4
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Birch EE, Duffy KR. Leveraging neural plasticity for the treatment of amblyopia. Surv Ophthalmol 2024; 69:818-832. [PMID: 38763223 PMCID: PMC11380599 DOI: 10.1016/j.survophthal.2024.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 04/27/2024] [Accepted: 04/29/2024] [Indexed: 05/21/2024]
Abstract
Amblyopia is a form of visual cortical impairment that arises from abnormal visual experience early in life. Most often, amblyopia is a unilateral visual impairment that can develop as a result of strabismus, anisometropia, or a combination of these conditions that result in discordant binocular experience. Characterized by reduced visual acuity and impaired binocular function, amblyopia places a substantial burden on the developing child. Although frontline treatment with glasses and patching can improve visual acuity, residual amblyopia remains for most children. Newer binocular-based therapies can elicit rapid recovery of visual acuity and may also improve stereoacuity in some children. Nevertheless, for both treatment modalities full recovery is elusive, recurrence of amblyopia is common, and improvements are negligible when treatment is administered at older ages. Insights derived from animal models about the factors that govern neural plasticity have been leveraged to develop innovative treatments for amblyopia. These novel therapies exhibit efficacy to promote recovery, and some are effective even at ages when conventional treatments fail to yield benefit. Approaches for enhancing visual system plasticity and promoting recovery from amblyopia include altering the balance between excitatory and inhibitory mechanisms, reversing the accumulation of proteins that inhibit plasticity, and harnessing the principles of metaplasticity. Although these therapies have exhibited promising results in animal models, their safety and ability to remediate amblyopia need to be evaluated in humans.
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Affiliation(s)
- Eileen E Birch
- Crystal Charity Ball Pediatric Vision Laboratory, Retina Foundation, Dallas, TX, USA; University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Kevin R Duffy
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
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5
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Huang Z, Tong C, Zhao Y, Jiang L, Deng L, Gao X, He J, Jiang J. An Au 25 nanocluster/MoS 2 vdWaals heterojunction phototransistor for chromamorphic visual-afterimage emulation. NANOSCALE 2024. [PMID: 39189366 DOI: 10.1039/d4nr02350a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
Color vision relies on three cone photoreceptors that are sensitive to different wavelengths of light. The interaction of three incident light wavelengths over time creates a fascinating color coupling perception, termed chromamorphic computing. However, the realization of this fascinating characteristic in semiconductor devices remains a great challenge. Herein, a mixed-dimensional optoelectronic transistor based on a novel metal nanocluster Au25(SC12H25)18 and two-dimensional MoS2 van der Waals (vdWaals) heterojunction is proposed for chromamorphic visual-afterimage emulation with red-green-blue three-color spatiotemporal coupling perception. This distinguished molecular-like electronic level of Au25 nanoclusters allows the transistor to have visible light-sensitive properties, endowing it with the ability to perceive color information. Moreover, the chromamorphic functions are realized using a color spatiotemporal coupling approach. By utilizing the photogating effect of light stimulus, the device exhibits visual experience-dependent plasticity in accordance with the Bienenstock-Cooper-Munro (BCM) learning rule. Most importantly, for the first time, intriguing visual afterimages could be implemented using a color sensitization approach based on a close relationship between visual persistence and negative afterimages. These results represent an important step towards a new generation of intelligent visual color perception systems for human-computer interaction, bionic robots, etc.
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Affiliation(s)
- Zhuohui Huang
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, Hunan 410083, China.
- State Key Laboratory of Precision Manufacturing for Extreme Service Performance, College of Mechanical and Electrical Engineering, Central South University, Changsha, Hunan 410083, China
| | - Chuanjia Tong
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, Hunan 410083, China.
| | - Yanbo Zhao
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, Hunan 410083, China.
| | - Leyong Jiang
- School of Physics and Electronics, Hunan Normal University, Changsha, Hunan 410081, China
| | - Lianwen Deng
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, Hunan 410083, China.
| | - Xiaohui Gao
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, Hunan 410083, China.
| | - Jun He
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, Hunan 410083, China.
| | - Jie Jiang
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, Hunan 410083, China.
- State Key Laboratory of Precision Manufacturing for Extreme Service Performance, College of Mechanical and Electrical Engineering, Central South University, Changsha, Hunan 410083, China
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6
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Hoagland A, Newman ZL, Cai Z, Isacoff EY. Circuit firing homeostasis following synaptic perturbation ensures robust behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.27.609984. [PMID: 39253468 PMCID: PMC11383027 DOI: 10.1101/2024.08.27.609984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/11/2024]
Abstract
Homeostatic regulation of excitability and synaptic transmission ensures stable neural circuit output under changing conditions. We find that pre- or postsynaptic weakening of motor neuron (MN) to muscle glutamatergic transmission in Drosophila larva has little impact on locomotion, suggesting non-synaptic compensatory mechanisms. In vivo imaging of MN to muscle synaptic transmission and MN activity both show that synaptic weakening increases activity in tonic type Ib MNs, but not in the phasic type Is MN that innervate the same muscles. Additionally, an inhibitory class of pre-MNs that innervates type Ib-but not Is-MNs decreases activity. Our experiments suggest that weakening of MN evoked synaptic release onto the muscle is compensated for by an increase in MN firing due to a combined cell-autonomous increase in excitability and decreased inhibitory central drive. Selectivity for type Ib MNs may serve to restore tonic drive while absence of firing adjustment in the convergent Is MN can maintain the contraction wave dynamics needed for locomotion.
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McGregor JN, Farris CA, Ensley S, Schneider A, Fosque LJ, Wang C, Tilden EI, Liu Y, Tu J, Elmore H, Ronayne KD, Wessel R, Dyer EL, Bhaskaran-Nair K, Holtzman DM, Hengen KB. Failure in a population: Tauopathy disrupts homeostatic set-points in emergent dynamics despite stability in the constituent neurons. Neuron 2024:S0896-6273(24)00578-6. [PMID: 39241778 DOI: 10.1016/j.neuron.2024.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 06/24/2024] [Accepted: 08/09/2024] [Indexed: 09/09/2024]
Abstract
Homeostatic regulation of neuronal activity is essential for robust computation; set-points, such as firing rate, are actively stabilized to compensate for perturbations. The disruption of brain function central to neurodegenerative disease likely arises from impairments of computationally essential set-points. Here, we systematically investigated the effects of tau-mediated neurodegeneration on all known set-points in neuronal activity. We continuously tracked hippocampal neuronal activity across the lifetime of a mouse model of tauopathy. We were unable to detect effects of disease in measures of single-neuron firing activity. By contrast, as tauopathy progressed, there was disruption of network-level neuronal activity, quantified by measuring neuronal pairwise interactions and criticality, a homeostatically controlled, ideal computational regime. Deviations in criticality correlated with symptoms, predicted underlying anatomical pathology, occurred in a sleep-wake-dependent manner, and could be used to reliably classify an animal's genotype. This work illustrates how neurodegeneration may disrupt the computational capacity of neurobiological systems.
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Affiliation(s)
- James N McGregor
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Clayton A Farris
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Sahara Ensley
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Aidan Schneider
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Leandro J Fosque
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Chao Wang
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University in Saint Louis, St. Louis, MO, USA; Institute for Brain Science and Disease, Chongqing Medical University, Chongqing 400016, China
| | - Elizabeth I Tilden
- Department of Neuroscience, Washington University in Saint Louis, St. Louis, MO, USA
| | - Yuqi Liu
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Jianhong Tu
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Halla Elmore
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Keenan D Ronayne
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA
| | - Ralf Wessel
- Department of Physics, Washington University in Saint Louis, St. Louis, MO, USA
| | - Eva L Dyer
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | | | - David M Holtzman
- Department of Neurology, Hope Center for Neurological Disorders, Knight Alzheimer's Disease Research Center, Washington University in Saint Louis, St. Louis, MO, USA
| | - Keith B Hengen
- Department of Biology, Washington University in Saint Louis, St. Louis, MO, USA.
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8
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Delahunty ET, Bisset LM, Kavanagh JJ. Short-latency afferent inhibition is reduced with cold-water immersion of a limb and remains reduced after removal from the cold stimulus. Exp Physiol 2024. [PMID: 39190835 DOI: 10.1113/ep091896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 08/12/2024] [Indexed: 08/29/2024]
Abstract
The experience of pain that is induced by extremely cold temperatures can exert a modulatory effect on motor cortex circuitry. Although it is known that immersion of a single limb in very cold water can increase corticomotor excitability it is unknown how afferent input to the cortex shapes excitatory and inhibitory processes. Therefore, the purpose of this study was to examine motor-evoked potentials (MEP), short-latency afferent inhibition (SAI) and long-latency afferent inhibition (LAI) in response to immersion of a single hand in cold water. Transcranial magnetic stimulation (TMS) was used to assess MEPs, and peripheral nerve stimulation of the median nerve paired with TMS was used to measure SAI and LAI in motor circuits of the ipsilateral hemisphere. Measurements were obtained from electromyography (EMG) of the first dorsal interosseous (FDI) at baseline, during cold-water immersion, and during recovery from cold-water immersion. The intervention caused unconditioned MEPs to increase during exposure to the cold stimulus (P = 0.008) which then returned to baseline levels once the hand was removed from the cold water. MEP responses were decoupled from SAI responses, where SAI was reduced during exposure to the cold stimulus (P = 0.005) and remained reduced compared to baseline when the hand was removed from the cold water (P = 0.002). The intervention had no effect on LAI. The uncoupling of SAI from MEPs during the recovery period suggests that the mechanisms underlying the modulation of corticospinal excitability by sensory input may be distinct from those affecting intracortical inhibitory circuits. HIGHLIGHTS: What is the central question of this study? Does immersion of a limb in very cold water influence corticospinal excitability and the level of afferent inhibition exerted on motor cortical circuits? What is the main finding and its importance? In additional to perception of temperature, immersion in 6°C water also induced perceptions of pain. Motor evoked potential (MEP) amplitude increased during immersion, and short-latency afferent inhibition (SAI) of the motor cortex was reduced during immersion; however, these responses differed after the limb was removed from the cold stimulus, as MEPs returned to normal levels while SAI remained suppressed.
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Affiliation(s)
- Eden T Delahunty
- Menzies Health Institute Queensland, Griffith University, Queensland, Australia
| | - Leanne M Bisset
- Menzies Health Institute Queensland, Griffith University, Queensland, Australia
| | - Justin J Kavanagh
- Menzies Health Institute Queensland, Griffith University, Queensland, Australia
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9
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Xiong A, Richmond JE, Kim H. Presynaptic neurons self-tune by inversely coupling neurotransmitter release with the abundance of CaV2 voltage-gated Ca 2+ channels. Proc Natl Acad Sci U S A 2024; 121:e2404969121. [PMID: 39172783 PMCID: PMC11363341 DOI: 10.1073/pnas.2404969121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 07/12/2024] [Indexed: 08/24/2024] Open
Abstract
The abundance of CaV2 voltage-gated calcium channels is linked to presynaptic homeostatic plasticity (PHP), a process that recalibrates synaptic strength to maintain the stability of neural circuits. However, the molecular and cellular mechanisms governing PHP and CaV2 channels are not completely understood. Here, we uncover a previously not described form of PHP in Caenorhabditis elegans, revealing an inverse regulatory relationship between the efficiency of neurotransmitter release and the abundance of UNC-2/CaV2 channels. Gain-of-function unc-2SL(S240L) mutants, which carry a mutation analogous to the one causing familial hemiplegic migraine type 1 in humans, showed markedly reduced channel abundance despite increased channel functionality. Reducing synaptic release in these unc-2SL(S240L) mutants restored channel levels to those observed in wild-type animals. Conversely, loss-of-function unc-2DA(D726A) mutants, which harbor the D726A mutation in the channel pore, exhibited a marked increase in channel abundance. Enhancing synaptic release in unc-2DA mutants reversed this increase in channel levels. Importantly, this homeostatic regulation of UNC-2 channel levels is accompanied by the structural remodeling of the active zone (AZ); specifically, unc-2DA mutants, which exhibit increased channel abundance, showed parallel increases in select AZ proteins. Finally, our forward genetic screen revealed that WWP-1, a HECT family E3 ubiquitin ligase, is a key homeostatic mediator that removes UNC-2 from synapses. These findings highlight a self-tuning PHP regulating UNC-2/CaV2 channel abundance along with AZ reorganization, ensuring synaptic strength and stability.
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Affiliation(s)
- Ame Xiong
- Discipline of Cell Biology & Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL60064
| | - Janet E. Richmond
- Department of Biological Sciences, University of Illinois, Chicago, IL60607
| | - Hongkyun Kim
- Discipline of Cell Biology & Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL60064
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Shore AN, Li K, Safari M, Qunies AM, Spitznagel BD, Weaver CD, Emmitte KA, Frankel WN, Weston MC. Heterozygous expression of a Kcnt1 gain-of-function variant has differential effects on SST- and PV-expressing cortical GABAergic neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.11.561953. [PMID: 37873369 PMCID: PMC10592778 DOI: 10.1101/2023.10.11.561953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
More than twenty recurrent missense gain-of-function (GOF) mutations have been identified in the sodium-activated potassium (KNa) channel gene KCNT1 in patients with severe developmental and epileptic encephalopathies (DEEs), most of which are resistant to current therapies. Defining the neuron types most vulnerable to KCNT1 GOF will advance our understanding of disease mechanisms and provide refined targets for precision therapy efforts. Here, we assessed the effects of heterozygous expression of a Kcnt1 GOF variant (Y777H) on KNa currents and neuronal physiology among cortical glutamatergic and GABAergic neurons in mice, including those expressing vasoactive intestinal polypeptide (VIP), somatostatin (SST), and parvalbumin (PV), to identify and model the pathogenic mechanisms of autosomal dominant KCNT1 GOF variants in DEEs. Although the Kcnt1-Y777H variant had no effects on glutamatergic or VIP neuron function, it increased subthreshold KNa currents in both SST and PV neurons but with opposite effects on neuronal output; SST neurons became hypoexcitable with a higher rheobase current and lower action potential (AP) firing frequency, whereas PV neurons became hyperexcitable with a lower rheobase current and higher AP firing frequency. Further neurophysiological and computational modeling experiments showed that the differential effects of the Y777H variant on SST and PV neurons are not likely due to inherent differences in these neuron types, but to an increased persistent sodium current in PV, but not SST, neurons. The Y777H variant also increased excitatory input onto, and chemical and electrical synaptic connectivity between, SST neurons. Together, these data suggest differential pathogenic mechanisms, both direct and compensatory, contribute to disease phenotypes, and provide a salient example of how a pathogenic ion channel variant can cause opposite functional effects in closely related neuron subtypes due to interactions with other ionic conductances.
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Affiliation(s)
- Amy N. Shore
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA
- Department of Neurological Sciences, University of Vermont, Burlington, VT, USA
| | - Keyong Li
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA
| | - Mona Safari
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA
- Translational Biology, Medicine, and Health Graduate Program, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Alshaima’a M. Qunies
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
- School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Brittany D. Spitznagel
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - C. David Weaver
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Kyle A. Emmitte
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Wayne N. Frankel
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University, New York, NY, USA
| | - Matthew C. Weston
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Neurobiology Research, Roanoke, VA, USA
- Department of Neurological Sciences, University of Vermont, Burlington, VT, USA
- Translational Biology, Medicine, and Health Graduate Program, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
- School of Neuroscience, Virginia Tech, Blacksburg, VA, USA
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11
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Schmidt CC, Tong R, Emptage NJ. GluN2A- and GluN2B-containing pre-synaptic N-methyl-d-aspartate receptors differentially regulate action potential-evoked Ca 2+ influx via modulation of SK channels. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230222. [PMID: 38853550 PMCID: PMC11343232 DOI: 10.1098/rstb.2023.0222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/07/2023] [Accepted: 01/02/2024] [Indexed: 06/11/2024] Open
Abstract
N-methyl-d-aspartate receptors (NMDARs) play a pivotal role in synaptic plasticity. While the functional role of post-synaptic NMDARs is well established, pre-synaptic NMDAR (pre-NMDAR) function is largely unexplored. Different pre-NMDAR subunit populations are documented at synapses, suggesting that subunit composition influences neuronal transmission. Here, we used electrophysiological recordings at Schaffer collateral-CA1 synapses partnered with Ca2+ imaging and glutamate uncaging at boutons of CA3 pyramidal neurones to reveal two populations of pre-NMDARs that contain either the GluN2A or GluN2B subunit. Activation of the GluN2B population decreases action potential-evoked Ca2+ influx via modulation of small-conductance Ca2+-activated K+ channels, while activation of the GluN2A population does the opposite. Critically, the level of functional expression of the subunits is subject to homeostatic regulation, bidirectionally affecting short-term facilitation, thus providing a capacity for a fine adjustment of information transfer. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Carla C. Schmidt
- Department of Pharmacology, University of Oxford, OxfordOX1 3QT, UK
| | - Rudi Tong
- Department of Pharmacology, University of Oxford, OxfordOX1 3QT, UK
- Montreal Neurological Institute, 3801 University Street, Montreal, QuebecH3A 2B4, Canada
| | - Nigel J. Emptage
- Department of Pharmacology, University of Oxford, OxfordOX1 3QT, UK
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12
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Harris KM, Kuwajima M, Flores JC, Zito K. Synapse-specific structural plasticity that protects and refines local circuits during LTP and LTD. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230224. [PMID: 38853547 DOI: 10.1098/rstb.2023.0224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 01/05/2024] [Indexed: 06/11/2024] Open
Abstract
Synapses form trillions of connections in the brain. Long-term potentiation (LTP) and long-term depression (LTD) are cellular mechanisms vital for learning that modify the strength and structure of synapses. Three-dimensional reconstruction from serial section electron microscopy reveals three distinct pre- to post-synaptic arrangements: strong active zones (AZs) with tightly docked vesicles, weak AZs with loose or non-docked vesicles, and nascent zones (NZs) with a postsynaptic density but no presynaptic vesicles. Importantly, LTP can be temporarily saturated preventing further increases in synaptic strength. At the onset of LTP, vesicles are recruited to NZs, converting them to AZs. During recovery of LTP from saturation (1-4 h), new NZs form, especially on spines where AZs are most enlarged by LTP. Sentinel spines contain smooth endoplasmic reticulum (SER), have the largest synapses and form clusters with smaller spines lacking SER after LTP recovers. We propose a model whereby NZ plasticity provides synapse-specific AZ expansion during LTP and loss of weak AZs that drive synapse shrinkage during LTD. Spine clusters become functionally engaged during LTP or disassembled during LTD. Saturation of LTP or LTD probably acts to protect recently formed memories from ongoing plasticity and may account for the advantage of spaced over massed learning. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Kristen M Harris
- Department of Neuroscience and Center for Learning and Memory, The University of Texas at Austin , Austin, TX 78712, USA
| | - Masaaki Kuwajima
- Department of Neuroscience and Center for Learning and Memory, The University of Texas at Austin , Austin, TX 78712, USA
| | - Juan C Flores
- Center for Neuroscience, University of California , Davis, CA 95618, USA
| | - Karen Zito
- Center for Neuroscience, University of California , Davis, CA 95618, USA
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13
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Zolezzi DM, Larsen DB, Zamorano AM, Graven-Nielsen T. Facilitation of Early and Middle Latency SEP after tDCS of M1: No Evidence of Primary Somatosensory Homeostatic Plasticity. Neuroscience 2024; 551:143-152. [PMID: 38735429 DOI: 10.1016/j.neuroscience.2024.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/09/2024] [Accepted: 05/01/2024] [Indexed: 05/14/2024]
Abstract
Homeostatic plasticity is a mechanism that stabilizes cortical excitability within a physiological range. Most homeostatic plasticity protocols have primed and tested the homeostatic response of the primary motor cortex (M1). This study investigated if a homeostatic response could be recorded from the primary sensory cortex (S1) after inducing homeostatic plasticity in M1. In 31 healthy participants, homeostatic plasticity was induced over M1 with a priming and testing block of transcranial direct current stimulation (tDCS) in two different sessions (anodal and cathodal). S1 excitability was assessed by early (N20, P25) and middle-latency (N33-P45) somatosensory evoked potentials (SEP) extracted from 4 electrodes (CP5, CP3, P5, P3). Baseline and post-measures (post-priming, 0-min, 10-min, and 20-min after homeostatic induction) were taken. Anodal M1 homeostatic plasticity induction significantly facilitated the N20-P25, P45 peak, and N33-P45 early SEP components up to 20-min post-induction, without any indication of a homeostatic response (i.e., reduced SEP). Cathodal homeostatic induction did not induce any significant effect on early or middle latency SEPs. M1 homeostatic plasticity induction by anodal stimulation protocol to the primary motor cortex did not induce a homeostatic response in SEPs.
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Affiliation(s)
- Daniela M Zolezzi
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Dennis B Larsen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Anna M Zamorano
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Thomas Graven-Nielsen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
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14
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Gruenbaum BF, Schonwald A, Boyko M, Zlotnik A. The Role of Glutamate and Blood-Brain Barrier Disruption as a Mechanistic Link between Epilepsy and Depression. Cells 2024; 13:1228. [PMID: 39056809 PMCID: PMC11275034 DOI: 10.3390/cells13141228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 07/10/2024] [Accepted: 07/19/2024] [Indexed: 07/28/2024] Open
Abstract
Epilepsy is associated with substantial neuropsychiatric impairments that persist long after the onset of the condition, significantly impacting quality of life. The goal of this review was to uncover how the pathological consequences of epilepsy, such as excessive glutamate release and a disrupted blood-brain barrier (BBB), contribute to the emergence of neuropsychiatric disorders. We hypothesize that epilepsy induces a dysfunctional BBB through hyperexcitation, which then further amplifies post-ictal glutamate levels and, thus, triggers neurodegenerative and neuropsychiatric processes. This review identifies the determinants of glutamate concentration levels in the brain and explores potential therapeutic interventions that restore BBB integrity. Our focus on therapeutic BBB restoration is guided by the premise that it may improve glutamate regulation, consequently mitigating the neurotoxicity that contributes to the onset of neuropsychiatric symptoms.
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Affiliation(s)
- Benjamin F. Gruenbaum
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, FL 32224, USA
| | | | - Matthew Boyko
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel; (M.B.); (A.Z.)
| | - Alexander Zlotnik
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel; (M.B.); (A.Z.)
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15
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Bagatelas ED, Kavalali ET. Chronic modulation of cAMP signaling elicits synaptic scaling irrespective of activity. iScience 2024; 27:110176. [PMID: 38989459 PMCID: PMC11233962 DOI: 10.1016/j.isci.2024.110176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/11/2024] [Accepted: 05/31/2024] [Indexed: 07/12/2024] Open
Abstract
Homeostatic plasticity mechanisms act in a negative feedback manner to stabilize neuronal firing around a set point. Classically, homeostatic synaptic plasticity is elicited via rather drastic manipulation of activity in a neuronal population. Here, we employed a chemogenetic approach to regulate activity via eliciting G protein-coupled receptor (GPCR) signaling in hippocampal neurons to trigger homeostatic synaptic plasticity. We demonstrate that chronic activation of hM4D(Gi) signaling induces mild and transient activity suppression, yet still triggers synaptic upscaling akin to tetrodotoxin (TTX)-induced complete activity suppression. Therefore, this homeostatic regulation was irrespective of Gi-signaling regulation of activity, but it was mimicked or occluded by direct manipulation of cyclic AMP (cAMP) signaling in a manner that intersected with the retinoic acid receptor alpha (RARα) signaling pathway. Our data suggest chemogenetic tools can uniquely be used to probe cell-autonomous mechanisms of synaptic scaling and operate via direct modulation of second messenger signaling bypassing activity regulation.
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Affiliation(s)
- Elena D. Bagatelas
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37209, USA
| | - Ege T. Kavalali
- Department of Pharmacology and the Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37209, USA
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16
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Gross J, Knipper M, Mazurek B. Candidate Key Proteins in Tinnitus-A Bioinformatic Study of Synaptic Transmission in the Cochlear Nucleus. Biomedicines 2024; 12:1615. [PMID: 39062188 PMCID: PMC11274367 DOI: 10.3390/biomedicines12071615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 07/11/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
The aim of this study was to identify key proteins of synaptic transmission in the cochlear nucleus (CN) that are involved in normal hearing, acoustic stimulation, and tinnitus. A gene list was compiled from the GeneCards database using the keywords "synaptic transmission" AND "tinnitus" AND "cochlear nucleus" (Tin). For comparison, two gene lists with the keywords "auditory perception" (AP) AND "acoustic stimulation" (AcouStim) were built. The STRING protein-protein interaction (PPI) network and the Cytoscape data analyzer were used to identify the top two high-degree proteins (HDPs) and their high-score interaction proteins (HSIPs), together referred to as key proteins. The top1 key proteins of the Tin-process were BDNF, NTRK1, NTRK3, and NTF3; the top2 key proteins are FOS, JUN, CREB1, EGR1, MAPK1, and MAPK3. Highly significant GO terms in CN in tinnitus were "RNA polymerase II transcription factor complex", "late endosome", cellular response to cadmium ion", "cellular response to reactive oxygen species", and "nerve growth factor signaling pathway", indicating changes in vesicle and cell homeostasis. In contrast to the spiral ganglion, where important changes in tinnitus are characterized by processes at the level of cells, important biological changes in the CN take place at the level of synapses and transcription.
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Affiliation(s)
- Johann Gross
- Tinnitus Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
- Leibniz Society of Science Berlin, 10117 Berlin, Germany;
| | - Marlies Knipper
- Leibniz Society of Science Berlin, 10117 Berlin, Germany;
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, 72076 Tübingen, Germany
| | - Birgit Mazurek
- Tinnitus Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany;
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17
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Thompson B, Concetta Morrone M, Bex P, Lozama A, Sabel BA. Harnessing brain plasticity to improve binocular vision in amblyopia: An evidence-based update. Eur J Ophthalmol 2024; 34:901-912. [PMID: 37431104 PMCID: PMC11295393 DOI: 10.1177/11206721231187426] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 06/11/2023] [Indexed: 07/12/2023]
Abstract
Amblyopia is a developmental visual disorder resulting from atypical binocular experience in early childhood that leads to abnormal visual cortex development and vision impairment. Recovery from amblyopia requires significant visual cortex neuroplasticity, i.e. the ability of the central nervous system and its synaptic connections to adapt their structure and function. There is a high level of neuroplasticity in early development and, historically, neuroplastic responses to changes in visual experience were thought to be restricted to a "critical period" in early life. However, as our review now shows, the evidence is growing that plasticity of the adult visual system can also be harnessed to improve vision in amblyopia. Amblyopia treatment involves correcting refractive error to ensure clear and equal retinal image formation in both eyes, then, if necessary, promoting the use of the amblyopic eye by hindering or reducing visual input from the better eye through patching or pharmacologic therapy. Early treatment in children can lead to visual acuity gains and the development of binocular vision in some cases; however, many children do not respond to treatment, and many adults with amblyopia have historically been untreated or undertreated. Here we review the current evidence on how dichoptic training can be used as a novel binocular therapeutic approach to facilitate visual processing of input from the amblyopic eye and can simultaneously engage both eyes in a training task that requires binocular integration. It is a novel and promising treatment for amblyopia in both children and adults.
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Affiliation(s)
- Benjamin Thompson
- Department of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada
- Centre for Eye and Vision Science, Hong Kong
| | - Maria Concetta Morrone
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Peter Bex
- Department of Psychology, Northeastern University, Boston, MA, USA
| | - Anthony Lozama
- Novartis Pharmaceutical Corporation, East Hanover, NJ, USA
| | - Bernhard A. Sabel
- Institute of Medical Psychology, Faculty of Medicine, Otto-von-Guericke University of Magdeburg, Magdeburg, Germany
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18
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Van Hook MJ, McCool S. Enhanced Synaptic Inhibition in the Dorsolateral Geniculate Nucleus in a Mouse Model of Glaucoma. eNeuro 2024; 11:ENEURO.0263-24.2024. [PMID: 38937109 PMCID: PMC11242868 DOI: 10.1523/eneuro.0263-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Accepted: 06/20/2024] [Indexed: 06/29/2024] Open
Abstract
Elevated intraocular pressure (IOP) triggers glaucoma by damaging the output neurons of the retina called retinal ganglion cells (RGCs). This leads to the loss of RGC signaling to visual centers of the brain such as the dorsolateral geniculate nucleus (dLGN), which is critical for processing and relaying information to the cortex for conscious vision. In response to altered levels of activity or synaptic input, neurons can homeostatically modulate postsynaptic neurotransmitter receptor numbers, allowing them to scale their synaptic responses to stabilize spike output. While prior work has indicated unaltered glutamate receptor properties in the glaucomatous dLGN, it is unknown whether glaucoma impacts dLGN inhibition. Here, using DBA/2J mice, which develop elevated IOP beginning at 6-7 months of age, we tested whether the strength of inhibitory synapses on dLGN thalamocortical relay neurons is altered in response to the disease state. We found an enhancement of feedforward disynaptic inhibition arising from local interneurons along with increased amplitude of quantal inhibitory synaptic currents. A combination of immunofluorescence staining for the γ-aminobutyric acid (GABA)A-α1 receptor subunit, peak-scaled nonstationary fluctuation analysis, and measures of homeostatic synaptic scaling pointed to an ∼1.4-fold increase in GABA receptors at postsynaptic inhibitory synapses, although several pieces of evidence indicate a nonuniform scaling across inhibitory synapses within individual relay neurons. Together, these results indicate an increase in inhibitory synaptic strength in the glaucomatous dLGN, potentially pointing toward homeostatic compensation for disruptions in network and neuronal function triggered by increased IOP.
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Affiliation(s)
- Matthew J Van Hook
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198
- Departments of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Shaylah McCool
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198
- Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska 68198
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19
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Gonzalez-Islas C, Sabra Z, Fong MF, Yilmam P, Au Yong N, Engisch K, Wenner P. GABAergic synaptic scaling is triggered by changes in spiking activity rather than AMPA receptor activation. eLife 2024; 12:RP87753. [PMID: 38941139 PMCID: PMC11213567 DOI: 10.7554/elife.87753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2024] Open
Abstract
Homeostatic plasticity represents a set of mechanisms that are thought to recover some aspect of neural function. One such mechanism called AMPAergic scaling was thought to be a likely candidate to homeostatically control spiking activity. However, recent findings have forced us to reconsider this idea as several studies suggest AMPAergic scaling is not directly triggered by changes in spiking. Moreover, studies examining homeostatic perturbations in vivo have suggested that GABAergic synapses may be more critical in terms of spiking homeostasis. Here, we show results that GABAergic scaling can act to homeostatically control spiking levels. We found that perturbations which increased or decreased spiking in cortical cultures triggered multiplicative GABAergic upscaling and downscaling, respectively. In contrast, we found that changes in AMPA receptor (AMPAR) or GABAR transmission only influence GABAergic scaling through their indirect effect on spiking. We propose that GABAergic scaling represents a stronger candidate for spike rate homeostat than AMPAergic scaling.
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Affiliation(s)
- Carlos Gonzalez-Islas
- Department of Cell Biology, Emory UniversityAtlantaUnited States
- Doctorado en Ciencias Biológicas Universidad Autónoma de TlaxcalaTlaxMexico
| | - Zahraa Sabra
- Department of Neurosurgery, Emory UniversityAtlantaUnited States
| | - Ming-fai Fong
- Department of Cell Biology, Emory UniversityAtlantaUnited States
- Department of Biomedical Engineering, Georgia Tech and Emory UniversityAtlantaUnited States
| | - Pernille Yilmam
- Department of Cell Biology, Emory UniversityAtlantaUnited States
| | - Nicholas Au Yong
- Department of Neurosurgery, Emory UniversityAtlantaUnited States
| | - Kathrin Engisch
- Department of Neuroscience, Cell Biology and Physiology, Wright State UniversityDaytonUnited States
| | - Peter Wenner
- Department of Cell Biology, Emory UniversityAtlantaUnited States
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20
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Ciuro M, Sangiorgio M, Cacciato V, Cantone G, Fichera C, Salvatorelli L, Magro G, Leanza G, Vecchio M, Valle MS, Gulino R. Mitigating the Functional Deficit after Neurotoxic Motoneuronal Loss by an Inhibitor of Mitochondrial Fission. Int J Mol Sci 2024; 25:7059. [PMID: 39000168 PMCID: PMC11241433 DOI: 10.3390/ijms25137059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/15/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an extremely complex neurodegenerative disease involving different cell types, but motoneuronal loss represents its main pathological feature. Moreover, compensatory plastic changes taking place in parallel to neurodegeneration are likely to affect the timing of ALS onset and progression and, interestingly, they might represent a promising target for disease-modifying treatments. Therefore, a simplified animal model mimicking motoneuronal loss without the other pathological aspects of ALS has been established by means of intramuscular injection of cholera toxin-B saporin (CTB-Sap), which is a targeted neurotoxin able to kill motoneurons by retrograde suicide transport. Previous studies employing the mouse CTB-Sap model have proven that spontaneous motor recovery is possible after a subtotal removal of a spinal motoneuronal pool. Although these kinds of plastic changes are not enough to counteract the functional effects of the progressive motoneuron degeneration, it would nevertheless represent a promising target for treatments aiming to postpone ALS onset and/or delay disease progression. Herein, the mouse CTB-Sap model has been used to test the efficacy of mitochondrial division inhibitor 1 (Mdivi-1) as a tool to counteract the CTB-Sap toxicity and/or to promote neuroplasticity. The homeostasis of mitochondrial fission/fusion dynamics is indeed important for cell integrity, and it could be affected during neurodegeneration. Lesioned mice were treated with Mdivi-1 and then examined by a series of behavioral test and histological analyses. The results have shown that the drug may be capable of reducing functional deficits after the lesion and promoting synaptic plasticity and neuroprotection, thus representing a putative translational approach for motoneuron disorders.
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Affiliation(s)
- Maria Ciuro
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (M.C.); (M.S.); (V.C.); (G.C.); (C.F.); (M.V.); (M.S.V.)
| | - Maria Sangiorgio
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (M.C.); (M.S.); (V.C.); (G.C.); (C.F.); (M.V.); (M.S.V.)
| | - Valeria Cacciato
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (M.C.); (M.S.); (V.C.); (G.C.); (C.F.); (M.V.); (M.S.V.)
| | - Giuliano Cantone
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (M.C.); (M.S.); (V.C.); (G.C.); (C.F.); (M.V.); (M.S.V.)
| | - Carlo Fichera
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (M.C.); (M.S.); (V.C.); (G.C.); (C.F.); (M.V.); (M.S.V.)
| | - Lucia Salvatorelli
- Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, Anatomic Pathology, University of Catania, 95123 Catania, Italy; (L.S.); (G.M.)
| | - Gaetano Magro
- Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, Anatomic Pathology, University of Catania, 95123 Catania, Italy; (L.S.); (G.M.)
| | - Giampiero Leanza
- Department of Drug and Health Sciences, University of Catania, 95125 Catania, Italy;
| | - Michele Vecchio
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (M.C.); (M.S.); (V.C.); (G.C.); (C.F.); (M.V.); (M.S.V.)
| | - Maria Stella Valle
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (M.C.); (M.S.); (V.C.); (G.C.); (C.F.); (M.V.); (M.S.V.)
| | - Rosario Gulino
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (M.C.); (M.S.); (V.C.); (G.C.); (C.F.); (M.V.); (M.S.V.)
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21
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Nadafian A, Ganjtabesh M. Bioplausible Unsupervised Delay Learning for Extracting Spatiotemporal Features in Spiking Neural Networks. Neural Comput 2024; 36:1332-1352. [PMID: 38776969 DOI: 10.1162/neco_a_01674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 03/06/2024] [Indexed: 05/25/2024]
Abstract
The plasticity of the conduction delay between neurons plays a fundamental role in learning temporal features that are essential for processing videos, speech, and many high-level functions. However, the exact underlying mechanisms in the brain for this modulation are still under investigation. Devising a rule for precisely adjusting the synaptic delays could eventually help in developing more efficient and powerful brain-inspired computational models. In this article, we propose an unsupervised bioplausible learning rule for adjusting the synaptic delays in spiking neural networks. We also provide the mathematical proofs to show the convergence of our rule in learning spatiotemporal patterns. Furthermore, to show the effectiveness of our learning rule, we conducted several experiments on random dot kinematogram and a subset of DVS128 Gesture data sets. The experimental results indicate the efficiency of applying our proposed delay learning rule in extracting spatiotemporal features in an STDP-based spiking neural network.
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Affiliation(s)
- Alireza Nadafian
- School of Mathematics, Statistics, and Computer Science, College of Science, University of Tehran, Tehran, Iran
| | - Mohammad Ganjtabesh
- School of Mathematics, Statistics, and Computer Science, College of Science, University of Tehran, Tehran, Iran
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22
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Fukata Y, Fukata M, MacGillavry HD, Nair D, Hosy E. Celebrating the Birthday of AMPA Receptor Nanodomains: Illuminating the Nanoscale Organization of Excitatory Synapses with 10 Nanocandles. J Neurosci 2024; 44:e2104232024. [PMID: 38839340 PMCID: PMC11154862 DOI: 10.1523/jneurosci.2104-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 06/07/2024] Open
Abstract
A decade ago, in 2013, and over the course of 4 summer months, three separate observations were reported that each shed light independently on a new molecular organization that fundamentally reshaped our perception of excitatory synaptic transmission (Fukata et al., 2013; MacGillavry et al., 2013; Nair et al., 2013). This discovery unveiled an intricate arrangement of AMPA-type glutamate receptors and their principal scaffolding protein PSD-95, at synapses. This breakthrough was made possible, thanks to advanced super-resolution imaging techniques. It fundamentally changed our understanding of excitatory synaptic architecture and paved the way for a brand-new area of research. In this Progressions article, the primary investigators of the nanoscale organization of synapses have come together to chronicle the tale of their discovery. We recount the initial inquiry that prompted our research, the preceding studies that inspired our work, the technical obstacles that were encountered, and the breakthroughs that were made in the subsequent decade in the realm of nanoscale synaptic transmission. We review the new discoveries made possible by the democratization of super-resolution imaging techniques in the field of excitatory synaptic physiology and architecture, first by the extension to other glutamate receptors and to presynaptic proteins and then by the notion of trans-synaptic organization. After describing the organizational modifications occurring in various pathologies, we discuss briefly the latest technical developments made possible by super-resolution imaging and emerging concepts in synaptic physiology.
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Affiliation(s)
- Yuko Fukata
- Division of Molecular and Cellular Pharmacology, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Division of Neuropharmacology, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
| | - Harold D MacGillavry
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, The Netherlands
| | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Eric Hosy
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, CNRS UMR5297, Bordeaux F-33000, France
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23
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Kwon S, Park KS, Yoon KH. Regulator of Lipid Metabolism NHR-49 Mediates Pathogen Avoidance through Precise Control of Neuronal Activity. Cells 2024; 13:978. [PMID: 38891110 PMCID: PMC11172349 DOI: 10.3390/cells13110978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 05/24/2024] [Accepted: 05/30/2024] [Indexed: 06/21/2024] Open
Abstract
Precise control of neuronal activity is crucial for the proper functioning of neurons. How lipid homeostasis contributes to neuronal activity and how much of it is regulated by cells autonomously is unclear. In this study, we discovered that absence of the lipid regulator nhr-49, a functional ortholog of the peroxisome proliferator-activated receptor (PPAR) in Caenorhabditis elegans, resulted in defective pathogen avoidance behavior against Pseudomonas aeruginosa (PA14). Functional NHR-49 was required in the neurons, and more specifically, in a set of oxygen-sensing body cavity neurons, URX, AQR, and PQR. We found that lowering the neuronal activity of the body cavity neurons improved avoidance in nhr-49 mutants. Calcium imaging in URX neurons showed that nhr-49 mutants displayed longer-lasting calcium transients in response to an O2 upshift, suggesting that excess neuronal activity leads to avoidance defects. Cell-specific rescue of NHR-49 in the body cavity neurons was sufficient to improve pathogen avoidance, as well as URX neuron calcium kinetics. Supplementation with oleic acid also improved avoidance behavior and URX calcium kinetics, suggesting that the defective calcium response in the neuron is due to lipid dysfunction. These findings highlight the role of cell-autonomous lipid regulation in neuronal physiology and immune behavior.
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Affiliation(s)
- Saebom Kwon
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea;
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea;
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea
| | - Kyoung-hye Yoon
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea
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Wen W, Turrigiano GG. Modular Arrangement of Synaptic and Intrinsic Homeostatic Plasticity within Visual Cortical Circuits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.01.596982. [PMID: 38853882 PMCID: PMC11160741 DOI: 10.1101/2024.06.01.596982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Neocortical circuits use synaptic and intrinsic forms of homeostatic plasticity to stabilize key features of network activity, but whether these different homeostatic mechanisms act redundantly, or can be independently recruited to stabilize different network features, is unknown. Here we used pharmacological and genetic perturbations both in vitro and in vivo to determine whether synaptic scaling and intrinsic homeostatic plasticity (IHP) are arranged and recruited in a hierarchical or modular manner within L2/3 pyramidal neurons in rodent V1. Surprisingly, although the expression of synaptic scaling and IHP was dependent on overlapping trafficking pathways, they could be independently recruited by manipulating spiking activity or NMDAR signaling, respectively. Further, we found that changes in visual experience that affect NMDAR activation but not mean firing selectively trigger IHP, without recruiting synaptic scaling. These findings support a modular model in which synaptic and intrinsic homeostatic plasticity respond to and stabilize distinct aspects of network activity.
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Affiliation(s)
- Wei Wen
- Department of Biology, Brandeis University, Waltham, MA 02453, USA
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25
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Vitale C, Natali G, Cerullo MS, Floss T, Michetti C, Grasselli G, Benfenati F. The homeostatic effects of the RE-1 silencing transcription factor on cortical networks are altered under ictogenic conditions in the mouse. Acta Physiol (Oxf) 2024; 240:e14146. [PMID: 38606882 DOI: 10.1111/apha.14146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 02/22/2024] [Accepted: 04/02/2024] [Indexed: 04/13/2024]
Abstract
AIM The Repressor Element-1 Silencing Transcription Factor (REST) is an epigenetic master regulator playing a crucial role in the nervous system. In early developmental stages, REST downregulation promotes neuronal differentiation and the acquisition of the neuronal phenotype. In addition, postnatal fluctuations in REST expression contribute to shaping neuronal networks and maintaining network homeostasis. Here we investigate the role of the early postnatal deletion of neuronal REST in the assembly and strength of excitatory and inhibitory synaptic connections. METHODS We investigated excitatory and inhibitory synaptic transmission by patch-clamp recordings in acute neocortical slices in a conditional knockout mouse model (RestGTi) in which Rest was deleted by delivering PHP.eB adeno-associated viruses encoding CRE recombinase under the control of the human synapsin I promoter in the lateral ventricles of P0-P1 pups. RESULTS We show that, under physiological conditions, Rest deletion increased the intrinsic excitability of principal cortical neurons in the primary visual cortex and the density and strength of excitatory synaptic connections impinging on them, without affecting inhibitory transmission. Conversely, in the presence of a pathological excitation/inhibition imbalance induced by pentylenetetrazol, Rest deletion prevented the increase in synaptic excitation and decreased seizure severity. CONCLUSION The data indicate that REST exerts distinct effects on the excitability of cortical circuits depending on whether it acts under physiological conditions or in the presence of pathologic network hyperexcitability. In the former case, REST preserves a correct excitatory/inhibitory balance in cortical circuits, while in the latter REST loses its homeostatic activity and may become pro-epileptogenic.
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Affiliation(s)
- Carmela Vitale
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Giulia Natali
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Maria Sabina Cerullo
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Thomas Floss
- Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt, Neuherberg, Germany
| | - Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Experimental Medicine, University of Genova, Genova, Italy
| | - Giorgio Grasselli
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
- Department of Pharmacy, University of Genova, Genova, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
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26
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Pigareva Y, Gladkov A, Kolpakov V, Kazantsev VB, Mukhina I, Pimashkin A. The Profile of Network Spontaneous Activity and Functional Organization Interplay in Hierarchically Connected Modular Neural Networks In Vitro. MICROMACHINES 2024; 15:732. [PMID: 38930702 PMCID: PMC11205292 DOI: 10.3390/mi15060732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/23/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024]
Abstract
Modern microtechnology methods are widely used to create neural networks on a chip with a connection architecture demonstrating properties of modularity and hierarchy similar to brain networks. Such in vitro networks serve as a valuable model for studying the interplay of functional architecture within modules, their activity, and the effectiveness of inter-module interaction. In this study, we use a two-chamber microfluidic platform to investigate functional connectivity and global activity in hierarchically connected modular neural networks. We found that the strength of functional connections within the module and the profile of network spontaneous activity determine the effectiveness of inter-modular interaction and integration activity in the network. The direction of intermodular activity propagation configures the different densities of inhibitory synapses in the network. The developed microfluidic platform holds the potential to explore function-structure relationships and efficient information processing in two- or multilayer neural networks, in both healthy and pathological states.
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Affiliation(s)
- Yana Pigareva
- Neurotechnology Department, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
- Central Research Laboratory, Cell Technology Department, Privolzhsky Research Medical University, Nizhny Novgorod 603005, Russia
| | - Arseniy Gladkov
- Neurotechnology Department, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
- Central Research Laboratory, Cell Technology Department, Privolzhsky Research Medical University, Nizhny Novgorod 603005, Russia
| | - Vladimir Kolpakov
- Neurotechnology Department, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
- Central Research Laboratory, Cell Technology Department, Privolzhsky Research Medical University, Nizhny Novgorod 603005, Russia
| | - Victor B. Kazantsev
- Neurotechnology Department, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
- Central Research Laboratory, Cell Technology Department, Privolzhsky Research Medical University, Nizhny Novgorod 603005, Russia
| | - Irina Mukhina
- Neurotechnology Department, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
- Central Research Laboratory, Cell Technology Department, Privolzhsky Research Medical University, Nizhny Novgorod 603005, Russia
| | - Alexey Pimashkin
- Neurotechnology Department, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
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27
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Wake N, Shiramatsu TI, Takahashi H. Map plasticity following noise exposure in auditory cortex of rats: implications for disentangling neural correlates of tinnitus and hyperacusis. Front Neurosci 2024; 18:1385942. [PMID: 38881748 PMCID: PMC11176560 DOI: 10.3389/fnins.2024.1385942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 05/16/2024] [Indexed: 06/18/2024] Open
Abstract
Introduction Both tinnitus and hyperacusis, likely triggered by hearing loss, can be attributed to maladaptive plasticity in auditory perception. However, owing to their co-occurrence, disentangling their neural mechanisms proves difficult. We hypothesized that the neural correlates of tinnitus are associated with neural activities triggered by low-intensity tones, while hyperacusis is linked to responses to moderate- and high-intensity tones. Methods To test these hypotheses, we conducted behavioral and electrophysiological experiments in rats 2 to 8 days after traumatic tone exposure. Results In the behavioral experiments, prepulse and gap inhibition tended to exhibit different frequency characteristics (although not reaching sufficient statistical levels), suggesting that exposure to traumatic tones led to acute symptoms of hyperacusis and tinnitus at different frequency ranges. When examining the auditory cortex at the thalamocortical recipient layer, we observed that tinnitus symptoms correlated with a disorganized tonotopic map, typically characterized by responses to low-intensity tones. Neural correlates of hyperacusis were found in the cortical recruitment function at the multi-unit activity (MUA) level, but not at the local field potential (LFP) level, in response to moderate- and high-intensity tones. This shift from LFP to MUA was associated with a loss of monotonicity, suggesting a crucial role for inhibitory synapses. Discussion Thus, in acute symptoms of traumatic tone exposure, our experiments successfully disentangled the neural correlates of tinnitus and hyperacusis at the thalamocortical recipient layer of the auditory cortex. They also suggested that tinnitus is linked to central noise, whereas hyperacusis is associated with aberrant gain control. Further interactions between animal experiments and clinical studies will offer insights into neural mechanisms, diagnosis and treatments of tinnitus and hyperacusis, specifically in terms of long-term plasticity of chronic symptoms.
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Affiliation(s)
- Naoki Wake
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Tomoyo I Shiramatsu
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Hirokazu Takahashi
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
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28
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Sun SED, Levenstein D, Li B, Mandelberg N, Chenouard N, Suutari BS, Sanchez S, Tian G, Rinzel J, Buzsáki G, Tsien RW. Synaptic homeostasis transiently leverages Hebbian mechanisms for a multiphasic response to inactivity. Cell Rep 2024; 43:113839. [PMID: 38507409 DOI: 10.1016/j.celrep.2024.113839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 12/19/2023] [Accepted: 02/05/2024] [Indexed: 03/22/2024] Open
Abstract
Homeostatic regulation of synapses is vital for nervous system function and key to understanding a range of neurological conditions. Synaptic homeostasis is proposed to operate over hours to counteract the destabilizing influence of long-term potentiation (LTP) and long-term depression (LTD). The prevailing view holds that synaptic scaling is a slow first-order process that regulates postsynaptic glutamate receptors and fundamentally differs from LTP or LTD. Surprisingly, we find that the dynamics of scaling induced by neuronal inactivity are not exponential or monotonic, and the mechanism requires calcineurin and CaMKII, molecules dominant in LTD and LTP. Our quantitative model of these enzymes reconstructs the unexpected dynamics of homeostatic scaling and reveals how synapses can efficiently safeguard future capacity for synaptic plasticity. This mechanism of synaptic adaptation supports a broader set of homeostatic changes, including action potential autoregulation, and invites further inquiry into how such a mechanism varies in health and disease.
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Affiliation(s)
- Simón E D Sun
- Center for Neural Science, New York University, New York, NY 10003, USA; Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Daniel Levenstein
- Center for Neural Science, New York University, New York, NY 10003, USA; Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA; Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, 3810 University Street, Montreal, QC, Canada
| | - Boxing Li
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA; Neuroscience Program, Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine and the Fifth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510810, China
| | - Nataniel Mandelberg
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA
| | - Nicolas Chenouard
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA; Sorbonne Université, INSERM U1127, UMR CNRS 7225, Institut du Cerveau (ICM), 47 bld de l'hôpital, 75013 Paris, France
| | - Benjamin S Suutari
- Center for Neural Science, New York University, New York, NY 10003, USA; Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA
| | - Sandrine Sanchez
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA
| | - Guoling Tian
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA
| | - John Rinzel
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - György Buzsáki
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA
| | - Richard W Tsien
- Center for Neural Science, New York University, New York, NY 10003, USA; Department of Neuroscience and Physiology, Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA.
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29
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Carretero-Guillén A, Treviño M, Gómez-Climent MÁ, Dogbevia GK, Bertocchi I, Sprengel R, Larkum ME, Vlachos A, Gruart A, Delgado-García JM, Hasan MT. Dentate gyrus is needed for memory retrieval. Mol Psychiatry 2024:10.1038/s41380-024-02546-0. [PMID: 38609585 DOI: 10.1038/s41380-024-02546-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/03/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024]
Abstract
The hippocampus is crucial for acquiring and retrieving episodic and contextual memories. In previous studies, the inactivation of dentate gyrus (DG) neurons by chemogenetic- and optogenetic-mediated hyperpolarization led to opposing conclusions about DG's role in memory retrieval. One study used Designer Receptors Exclusively Activated by Designer Drugs (DREADD)-mediated clozapine N-oxide (CNO)-induced hyperpolarization and reported that the previously formed memory was erased, thus concluding that denate gyrus is needed for memory maintenance. The other study used optogenetic with halorhodopsin induced hyperpolarization and reported and dentate gyrus is needed for memory retrieval. We hypothesized that this apparent discrepancy could be due to the length of hyperpolarization in previous studies; minutes by optogenetics and several hours by DREADD/CNO. Since hyperpolarization interferes with anterograde and retrograde neuronal signaling, it is possible that the memory engram in the dentate gyrus and the entorhinal to hippocampus trisynaptic circuit was erased by long-term, but not with short-term hyperpolarization. We developed and applied an advanced chemogenetic technology to selectively silence synaptic output by blocking neurotransmitter release without hyperpolarizing DG neurons to explore this apparent discrepancy. We performed in vivo electrophysiology during trace eyeblink in a rabbit model of associative learning. Our work shows that the DG output is required for memory retrieval. Based on previous and recent findings, we propose that the actively functional anterograde and retrograde neuronal signaling is necessary to preserve synaptic memory engrams along the entorhinal cortex to the hippocampal trisynaptic circuit.
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Affiliation(s)
- Alejandro Carretero-Guillén
- Division of Neuroscience, University Pablo de Olavide, Seville, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
| | - Mario Treviño
- Max Planck Institute for Medical Research, Heidelberg, Germany
- Instituto de Neurociencias, Universidad de Guadalajara, Guadalajara, 44130, México
| | | | - Godwin K Dogbevia
- Max Planck Institute for Medical Research, Heidelberg, Germany
- Health Canada, Ottawa, ON, Canada
| | - Ilaria Bertocchi
- Max Planck Institute for Medical Research, Heidelberg, Germany
- Neuroscience Institute Cavalieri-Ottolenghi (NICO), University of Turin, Turin, Italy
| | - Rolf Sprengel
- Max Planck Institute for Medical Research, Heidelberg, Germany
| | | | | | - Agnès Gruart
- Division of Neuroscience, University Pablo de Olavide, Seville, Spain
| | | | - Mazahir T Hasan
- Achucarro Basque Center for Neuroscience, Leioa, Spain.
- Max Planck Institute for Medical Research, Heidelberg, Germany.
- NeuroCure, Charité - Universitätsmedizin, Berlin, Germany.
- Ikerbasque - Basque Foundation for Science, Bilbao, Spain.
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30
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Godavarthi SK, Hiramoto M, Ignatyev Y, Levin JB, Li HQ, Pratelli M, Borchardt J, Czajkowski C, Borodinsky LN, Sweeney L, Cline HT, Spitzer NC. Postsynaptic receptors regulate presynaptic transmitter stability through transsynaptic bridges. Proc Natl Acad Sci U S A 2024; 121:e2318041121. [PMID: 38568976 PMCID: PMC11009644 DOI: 10.1073/pnas.2318041121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 02/27/2024] [Indexed: 04/05/2024] Open
Abstract
Stable matching of neurotransmitters with their receptors is fundamental to synapse function and reliable communication in neural circuits. Presynaptic neurotransmitters regulate the stabilization of postsynaptic transmitter receptors. Whether postsynaptic receptors regulate stabilization of presynaptic transmitters has received less attention. Here, we show that blockade of endogenous postsynaptic acetylcholine receptors (AChR) at the neuromuscular junction destabilizes the cholinergic phenotype in motor neurons and stabilizes an earlier, developmentally transient glutamatergic phenotype. Further, expression of exogenous postsynaptic gamma-aminobutyric acid type A receptors (GABAA receptors) in muscle cells stabilizes an earlier, developmentally transient GABAergic motor neuron phenotype. Both AChR and GABAA receptors are linked to presynaptic neurons through transsynaptic bridges. Knockdown of specific components of these transsynaptic bridges prevents stabilization of the cholinergic or GABAergic phenotypes. Bidirectional communication can enforce a match between transmitter and receptor and ensure the fidelity of synaptic transmission. Our findings suggest a potential role of dysfunctional transmitter receptors in neurological disorders that involve the loss of the presynaptic transmitter.
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Affiliation(s)
- Swetha K. Godavarthi
- Neurobiology Department, University of California San Diego, La Jolla, CA92093
- Kavli Institute for Brain & Mind, University of California San Diego, La Jolla, CA92093
| | - Masaki Hiramoto
- Neuroscience Department, The Scripps Research Institute, La Jolla, CA92037
| | - Yuri Ignatyev
- Institute of Science and Technology Austria, Klosterneuburg3400, Austria
| | - Jacqueline B. Levin
- Department of Physiology & Membrane Biology Shriners Hospital for Children Northern California, University of California Davis School of Medicine, Sacramento, CA95817
| | - Hui-quan Li
- Neurobiology Department, University of California San Diego, La Jolla, CA92093
- Kavli Institute for Brain & Mind, University of California San Diego, La Jolla, CA92093
| | - Marta Pratelli
- Neurobiology Department, University of California San Diego, La Jolla, CA92093
- Kavli Institute for Brain & Mind, University of California San Diego, La Jolla, CA92093
| | - Jennifer Borchardt
- Neuroscience Department, University of Wisconsin Madison, Madison, WI53705
| | - Cynthia Czajkowski
- Neuroscience Department, University of Wisconsin Madison, Madison, WI53705
| | - Laura N. Borodinsky
- Department of Physiology & Membrane Biology Shriners Hospital for Children Northern California, University of California Davis School of Medicine, Sacramento, CA95817
| | - Lora Sweeney
- Institute of Science and Technology Austria, Klosterneuburg3400, Austria
| | - Hollis T. Cline
- Neuroscience Department, The Scripps Research Institute, La Jolla, CA92037
| | - Nicholas C. Spitzer
- Neurobiology Department, University of California San Diego, La Jolla, CA92093
- Kavli Institute for Brain & Mind, University of California San Diego, La Jolla, CA92093
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31
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Zolezzi DM, Larsen DB, McPhee M, Graven-Nielsen T. Effects of pain on cortical homeostatic plasticity in humans: a systematic review. Pain Rep 2024; 9:e1141. [PMID: 38444774 PMCID: PMC10914232 DOI: 10.1097/pr9.0000000000001141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/09/2023] [Accepted: 12/28/2023] [Indexed: 03/07/2024] Open
Abstract
Homeostatic plasticity (HP) is a negative feedback mechanism that prevents excessive facilitation or depression of cortical excitability (CE). Cortical HP responses in humans have been investigated by using 2 blocks of noninvasive brain stimulation with a no-stimulation block in between. A healthy HP response is characterized by reduced CE after 2 excitatory stimulation blocks and increased CE when using inhibitory stimulation. Conversely, impaired HP responses have been demonstrated in experimental and chronic pain conditions. Therefore, this systematic review aimed to provide an overview of the effect of pain on cortical HP in humans. Scopus, Embase, and PubMed were searched from inception until November 20, 2023. The included studies (1) compared experimental or clinical pain conditions with healthy controls, (2) induced HP using 2 blocks of stimulation with a no-stimulation interval, and (3) evaluated CE measures such as motor-evoked potentials. Four studies were included, consisting of 5 experiments and 146 participants, of whom 63 were patients with chronic pain and 48 were subjected to an experimental pain model. This systematic review found support for an HP impairment in pain compared with that in pain-free states, reflected by a lack of CE reduction after excitatory-excitatory HP induction over the primary motor cortex. Inhibitory-inhibitory HP induction did not produce a consistent HP response across studies, independent of pain or pain-free states. Standardization of HP induction protocols and outcome calculations is needed to ensure reproducibility and study comparison. Future HP studies may consider investigating sensory domains including nociception, which would further our understanding of abnormal HP regulation in pain conditions.
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Affiliation(s)
- Daniela M. Zolezzi
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Dennis B. Larsen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Megan McPhee
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Thomas Graven-Nielsen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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32
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Billot A, Kiran S. Disentangling neuroplasticity mechanisms in post-stroke language recovery. BRAIN AND LANGUAGE 2024; 251:105381. [PMID: 38401381 PMCID: PMC10981555 DOI: 10.1016/j.bandl.2024.105381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/28/2023] [Accepted: 01/12/2024] [Indexed: 02/26/2024]
Abstract
A major objective in post-stroke aphasia research is to gain a deeper understanding of neuroplastic mechanisms that drive language recovery, with the ultimate goal of enhancing treatment outcomes. Subsequent to recent advances in neuroimaging techniques, we now have the ability to examine more closely how neural activity patterns change after a stroke. However, the way these neural activity changes relate to language impairments and language recovery is still debated. The aim of this review is to provide a theoretical framework to better investigate and interpret neuroplasticity mechanisms underlying language recovery in post-stroke aphasia. We detail two sets of neuroplasticity mechanisms observed at the synaptic level that may explain functional neuroimaging findings in post-stroke aphasia recovery at the network level: feedback-based homeostatic plasticity and associative Hebbian plasticity. In conjunction with these plasticity mechanisms, higher-order cognitive control processes dynamically modulate neural activity in other regions to meet communication demands, despite reduced neural resources. This work provides a network-level neurobiological framework for understanding neural changes observed in post-stroke aphasia and can be used to define guidelines for personalized treatment development.
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Affiliation(s)
- Anne Billot
- Center for Brain Recovery, Boston University, Boston, USA; Department of Psychology, Center for Brain Science, Harvard University, Cambridge, Massachusetts, USA; Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Swathi Kiran
- Center for Brain Recovery, Boston University, Boston, USA.
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33
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Van Hook MJ, McCool S. Nonuniform scaling of synaptic inhibition in the dorsolateral geniculate nucleus in a mouse model of glaucoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.27.587036. [PMID: 38586044 PMCID: PMC10996666 DOI: 10.1101/2024.03.27.587036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Elevated intraocular pressure (IOP) triggers glaucoma by damaging the output neurons of the retina called retinal ganglion cells (RGCs). This leads to the loss of RGC signaling to visual centers of the brain such as the dorsolateral geniculate nucleus (dLGN), which is critical for processing and relaying information to the cortex for conscious vision. In response to altered levels of activity or synaptic input, neurons can homeostatically modulate postsynaptic neurotransmitter receptor numbers, allowing them to scale their synaptic responses to stabilize spike output. While prior work has indicated unaltered glutamate receptor properties in the glaucomatous dLGN, it is unknown whether glaucoma impacts dLGN inhibition. Here, using DBA/2J mice, which develop elevated IOP beginning at 6-7 months of age, we tested whether the strength of inhibitory synapses on dLGN thalamocortical relay neurons is altered in response to the disease state. We found an enhancement of feed-forward disynaptic inhibition arising from local interneurons along with increased amplitude of quantal inhibitory synaptic currents. A combination of immunofluorescence staining for the GABA A -α1 receptor subunit, peak-scaled nonstationary fluctuation analysis, and measures of homeostatic synaptic scaling indicated this was the result of an approximately 1.4-fold increase in GABA receptor number at post-synaptic inhibitory synapses, although several pieces of evidence strongly indicate a non-uniform scaling across inhibitory synapses within individual relay neurons. Together, these results indicate an increase in inhibitory synaptic strength in the glaucomatous dLGN, potentially pointing toward homeostatic compensation for disruptions in network and neuronal function triggered by increased IOP. Significance Statement Elevated eye pressure in glaucoma leads to loss of retinal outputs to the dorsolateral geniculate nucleus (dLGN), which is critical for relaying information to the cortex for conscious vision. Alterations in neuronal activity, as could arise from excitatory synapse loss, can trigger homeostatic adaptations to synaptic function that attempt to maintain activity within a meaningful dynamic range, although whether this occurs uniformly at all synapses within a given neuron or is a non-uniform process is debated. Here, using a mouse model of glaucoma, we show that dLGN inhibitory synapses undergo non-uniform upregulation due to addition of post-synaptic GABA receptors. This is likely to be a neuronal adaptation to glaucomatous pathology in an important sub-cortical visual center.
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McMullan HM, Gansemer BM, Thayer SA. Antiretroviral drugs from multiple classes induce loss of excitatory synapses between hippocampal neurons in culture. Front Pharmacol 2024; 15:1369757. [PMID: 38533258 PMCID: PMC10963620 DOI: 10.3389/fphar.2024.1369757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 02/27/2024] [Indexed: 03/28/2024] Open
Abstract
Introduction: Antiretroviral (ARV) drugs have improved prognoses for people living with HIV. However, HIV-associated neurocognitive disorders (HAND) persist despite undetectable viral loads. Some ARVs have been linked to neuropsychiatric effects that may contribute to HAND. Synapse loss correlates with cognitive decline in HAND and synaptic deficits may contribute to the neuropsychiatric effects of ARV drugs. Methods: Using an automated high content assay, rat hippocampal neurons in culture expressing PSD95-eGFP to label glutamatergic synapses and mCherry to fill neuronal structures were imaged before and after treatment with 25 clinically used ARVs. Results and Discussion: At a concentration of 10 μM the protease inhibitors nelfinavir and saquinavir, the non-nucleoside reverse transcriptase inhibitors etravirine and the 8-OH metabolite of efavirenz, the integrase inhibitor bictegravir, and the capsid inhibitor lenacapavir produced synaptic toxicity. Only lenacapavir produced synapse loss at the nanomolar concentrations estimated free in the plasma, although all 4 ARV drugs induced synapse loss at Cmax. Evaluation of combination therapies did not reveal synergistic synaptic toxicity. Synapse loss developed fully by 24 h and persisted for at least 3 days. Bictegravir-induced synapse loss required activation of voltage-gated Ca2+ channels and bictegravir, etravirine, and lenacapavir produced synapse loss by an excitotoxic mechanism. These results indicate that select ARV drugs might contribute to neuropsychiatric effects in combination with drugs that bind serum proteins or in disease states in which synaptic function is altered. The high content imaging assay used here provides an efficient means to evaluate new drugs and drug combinations for potential CNS toxicity.
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Affiliation(s)
| | | | - Stanley A. Thayer
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, United States
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Sell GL, Barrow SL, McAllister AK. Glutamate signaling and neuroligin/neurexin adhesion play opposing roles that are mediated by major histocompatibility complex I molecules in cortical synapse formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.05.583626. [PMID: 38496590 PMCID: PMC10942384 DOI: 10.1101/2024.03.05.583626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Although neurons release neurotransmitter before contact, the role for this release in synapse formation remains unclear. Cortical synapses do not require synaptic vesicle release for formation 1-4 , yet glutamate clearly regulates glutamate receptor trafficking 5,6 and induces spine formation 7-11 . Using a culture system to dissect molecular mechanisms, we found that glutamate rapidly decreases synapse density specifically in young cortical neurons in a local and calcium-dependent manner through decreasing NMDAR transport and surface expression as well as co-transport with neuroligin (NL1). Adhesion between NL1 and neurexin 1 protects against this glutamate-induced synapse loss. Major histocompatibility I (MHCI) molecules are required for the effects of glutamate in causing synapse loss through negatively regulating NL1 levels. Thus, like acetylcholine at the NMJ, glutamate acts as a dispersal signal for NMDARs and causes rapid synapse loss unless opposed by NL1-mediated trans-synaptic adhesion. Together, glutamate, MHCI and NL1 mediate a novel form of homeostatic plasticity in young neurons that induces rapid changes in NMDARs to regulate when and where nascent glutamatergic synapses are formed.
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Rana S, Alom F, Martinez RC, Fuller DD, Mickle AD. Acute ampakines increase voiding function and coordination in a rat model of SCI. eLife 2024; 12:RP89767. [PMID: 38451184 PMCID: PMC10962400 DOI: 10.7554/elife.89767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024] Open
Abstract
Neurogenic bladder dysfunction causes urological complications and reduces the quality of life in persons with spinal cord injury (SCI). Glutamatergic signaling via AMPA receptors is fundamentally important to the neural circuits controlling bladder voiding. Ampakines are positive allosteric modulators of AMPA receptors that can enhance the function of glutamatergic neural circuits after SCI. We hypothesized that ampakines can acutely stimulate bladder voiding that has been impaired due to thoracic contusion SCI. Adult female Sprague-Dawley rats received a unilateral contusion of the T9 spinal cord (n = 10). Bladder function (cystometry) and coordination with the external urethral sphincter (EUS) were assessed 5 d post-SCI under urethane anesthesia. Data were compared to responses in spinal-intact rats (n = 8). The 'low-impact' ampakine CX1739 (5, 10, or 15 mg/kg) or vehicle (2-hydroxypropyl-beta-cyclodextrin [HPCD]) was administered intravenously. The HPCD vehicle had no discernible impact on voiding. In contrast, following CX1739, the pressure threshold for inducing bladder contraction, voided volume, and the interval between bladder contractions were significantly reduced. These responses occurred in a dose-dependent manner. We conclude that modulating AMPA receptor function using ampakines can rapidly improve bladder-voiding capability at subacute time points following contusion SCI. These results may provide a new and translatable method for therapeutic targeting of bladder dysfunction acutely after SCI.
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Affiliation(s)
- Sabhya Rana
- Department of Physical Therapy, University of FloridaGainesvilleUnited States
- McKnight Brain Institute, University of FloridaGainesvilleUnited States
- Breathing Research and Therapeutics CenterGainesvilleUnited States
| | - Firoj Alom
- Department of Physiological Sciences, College of Veterinary Medicine, University of FloridaGainesvilleUnited States
- Department of Veterinary and Animal Sciences, University of RajshahiRajshahiBangladesh
| | - Robert C Martinez
- Department of Physical Therapy, University of FloridaGainesvilleUnited States
- McKnight Brain Institute, University of FloridaGainesvilleUnited States
- Breathing Research and Therapeutics CenterGainesvilleUnited States
| | - David D Fuller
- Department of Physical Therapy, University of FloridaGainesvilleUnited States
- McKnight Brain Institute, University of FloridaGainesvilleUnited States
- Breathing Research and Therapeutics CenterGainesvilleUnited States
| | - Aaron D Mickle
- McKnight Brain Institute, University of FloridaGainesvilleUnited States
- Department of Physiological Sciences, College of Veterinary Medicine, University of FloridaGainesvilleUnited States
- Department of Veterinary and Animal Sciences, University of RajshahiRajshahiBangladesh
- J. Crayton Pruitt Family Department of Biomedical Engineering, College of Engineering, University of FloridaGainesvilleUnited States
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Sharma V, Swaminathan K, Shukla R. The Ribosome Hypothesis: Decoding Mood Disorder Complexity. Int J Mol Sci 2024; 25:2815. [PMID: 38474062 PMCID: PMC10931790 DOI: 10.3390/ijms25052815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/26/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
Several types of mood disorders lie along a continuum, with nebulous boundaries between them. Understanding the mechanisms that contribute to mood disorder complexity is critical for effective treatment. However, present treatments are largely centered around neurotransmission and receptor-based hypotheses, which, given the high instance of treatment resistance, fail to adequately explain the complexities of mood disorders. In this opinion piece, based on our recent results, we propose a ribosome hypothesis of mood disorders. We suggest that any hypothesis seeking to explain the diverse nature of mood disorders must incorporate infrastructure diversity that results in a wide range of effects. Ribosomes, with their mobility across neurites and complex composition, have the potential to become specialized during stress; thus, ribosome diversity and dysregulation are well suited to explaining mood disorder complexity. Here, we first establish a framework connecting ribosomes to the current state of knowledge associated with mood disorders. Then, we describe the potential mechanisms through which ribosomes could homeostatically regulate systems to manifest diverse mood disorder phenotypes and discuss approaches for substantiating the ribosome hypothesis. Investigating these mechanisms as therapeutic targets holds promise for transdiagnostic avenues targeting mood disorders.
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Affiliation(s)
- Vandana Sharma
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA;
- Department of Neurosciences, University of Wyoming, Laramie, WY 82071, USA
| | - Karthik Swaminathan
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA;
- Department of Neurosciences, University of Wyoming, Laramie, WY 82071, USA
| | - Rammohan Shukla
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA;
- Department of Neurosciences, University of Wyoming, Laramie, WY 82071, USA
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38
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Chen X, Tang SJ. Neural Circuitry Polarization in the Spinal Dorsal Horn (SDH): A Novel Form of Dysregulated Circuitry Plasticity during Pain Pathogenesis. Cells 2024; 13:398. [PMID: 38474361 PMCID: PMC10930392 DOI: 10.3390/cells13050398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
Pathological pain emerges from nociceptive system dysfunction, resulting in heightened pain circuit activity. Various forms of circuitry plasticity, such as central sensitization, synaptic plasticity, homeostatic plasticity, and excitation/inhibition balance, contribute to the malfunction of neural circuits during pain pathogenesis. Recently, a new form of plasticity in the spinal dorsal horn (SDH), named neural circuit polarization (NCP), was discovered in pain models induced by HIV-1 gp120 and chronic morphine administration. NCP manifests as an increase in excitatory postsynaptic currents (EPSCs) in excitatory neurons and a decrease in EPSCs in inhibitory neurons, presumably facilitating hyperactivation of pain circuits. The expression of NCP is associated with astrogliosis. Ablation of reactive astrocytes or suppression of astrogliosis blocks NCP and, concomitantly, the development of gp120- or morphine-induced pain. In this review, we aim to compare and integrate NCP with other forms of plasticity in pain circuits to improve the understanding of the pathogenic contribution of NCP and its cooperation with other forms of circuitry plasticity during the development of pathological pain.
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Affiliation(s)
| | - Shao-Jun Tang
- Stony Brook University Pain and Anesthesia Research Center (SPARC), Department of Anesthesiology, Stony Brook University, Stony Brook, NY 11794, USA;
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39
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Ren L. The mechanistic basis for the rapid antidepressant-like effects of ketamine: From neural circuits to molecular pathways. Prog Neuropsychopharmacol Biol Psychiatry 2024; 129:110910. [PMID: 38061484 DOI: 10.1016/j.pnpbp.2023.110910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023]
Abstract
Conventional antidepressants that target monoaminergic receptors require several weeks to be efficacious. This lag represents a significant problem in the currently available treatments for serious depression. Ketamine, acting as an N-methyl-d-aspartate receptor antagonist, was shown to have rapid antidepressant-like effects, marking a significant advancement in the study of mood disorders. However, serious side effects and adverse reactions limit its clinical use. Considering the limitations of ketamine, it is crucial to further define the network targets of ketamine. The rapid action of ketamine an as antidepressant is thought to be mediated by the glutamate system. It is believed that synaptic plasticity is essential for the rapid effects of ketamine as an antidepressant. Other mechanisms include the involvement of the γ-aminobutyric acidergic (GABAergic), 5-HTergic systems, and recent studies have linked astrocytes to ketamine's rapid antidepressant-like effects. The interactions between these systems exert a synergistic rapid antidepressant effect through neural circuits and molecular mechanisms. Here, we discuss the neural circuits and molecular mechanisms underlying the action of ketamine. This work will help explain how molecular and neural targets are responsible for the effects of rapidly acting antidepressants and will aid in the discovery of new therapeutic approaches for major depressive disorder.
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Affiliation(s)
- Li Ren
- School of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Sichuan Chengdu 611137, China.
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40
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Koesters AG, Rich MM, Engisch KL. Diverging from the Norm: Reevaluating What Miniature Excitatory Postsynaptic Currents Tell Us about Homeostatic Synaptic Plasticity. Neuroscientist 2024; 30:49-70. [PMID: 35904350 DOI: 10.1177/10738584221112336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The idea that the nervous system maintains a set point of network activity and homeostatically returns to that set point in the face of dramatic disruption-during development, after injury, in pathologic states, and during sleep/wake cycles-is rapidly becoming accepted as a key plasticity behavior, placing it alongside long-term potentiation and depression. The dramatic growth in studies of homeostatic synaptic plasticity of miniature excitatory synaptic currents (mEPSCs) is attributable, in part, to the simple yet elegant mechanism of uniform multiplicative scaling proposed by Turrigiano and colleagues: that neurons sense their own activity and globally multiply the strength of every synapse by a single factor to return activity to the set point without altering established differences in synaptic weights. We have recently shown that for mEPSCs recorded from control and activity-blocked cultures of mouse cortical neurons, the synaptic scaling factor is not uniform but is close to 1 for the smallest mEPSC amplitudes and progressively increases as mEPSC amplitudes increase, which we term divergent scaling. Using insights gained from simulating uniform multiplicative scaling, we review evidence from published studies and conclude that divergent synaptic scaling is the norm rather than the exception. This conclusion has implications for hypotheses about the molecular mechanisms underlying synaptic scaling.
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Affiliation(s)
- Andrew G Koesters
- Department of Behavior, Cognition, and Neurophysiology, Environmental Health Effects Laboratory, Naval Medical Research Unit-Dayton, Wright-Patterson AFB, OH, USA
| | - Mark M Rich
- Department of Neuroscience, Cell Biology, and Physiology, College of Science and Mathematics, and Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Kathrin L Engisch
- Department of Neuroscience, Cell Biology, and Physiology, College of Science and Mathematics, and Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
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Heuer SE, Nickerson EW, Howell GR, Bloss EB. Genetic context drives age-related disparities in synaptic maintenance and structure across cortical and hippocampal neuronal circuits. Aging Cell 2024; 23:e14033. [PMID: 38130024 PMCID: PMC10861192 DOI: 10.1111/acel.14033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 12/23/2023] Open
Abstract
The disconnection of neuronal circuitry through synaptic loss is presumed to be a major driver of age-related cognitive decline. Age-related cognitive decline is heterogeneous, yet whether genetic mechanisms differentiate successful from unsuccessful cognitive decline through maintenance or vulnerability of synaptic connections remains unknown. Previous work using rodent and primate models leveraged various techniques to imply that age-related synaptic loss is widespread on pyramidal cells in prefrontal cortex (PFC) circuits but absent on those in area CA1 of the hippocampus. Here, we examined the effect of aging on synapses on projection neurons forming a hippocampal-cortico-thalamic circuit important for spatial working memory tasks from two genetically distinct mouse strains that exhibit susceptibility (C57BL/6J) or resistance (PWK/PhJ) to cognitive decline during aging. Across both strains, synapse density on CA1-to-PFC projection neurons appeared completely intact with age. In contrast, we found synapse loss on PFC-to-nucleus reuniens (RE) projection neurons from aged C57BL/6J but not PWK/PhJ mice. Moreover, synapses from aged PWK/PhJ mice but not from C57BL/6J exhibited altered morphologies that suggest increased efficiency to drive depolarization in the parent dendrite. Our findings suggest resistance to age-related cognitive decline results in part by age-related synaptic adaptations, and identification of these mechanisms in PWK/PhJ mice could uncover new therapeutic targets for promoting successful cognitive aging and extending human health span.
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Affiliation(s)
- Sarah E. Heuer
- The Jackson LaboratoryBar HarborMaineUSA
- Tufts University Graduate School of Biomedical SciencesBostonMassachusettsUSA
| | - Emily W. Nickerson
- The Jackson LaboratoryBar HarborMaineUSA
- Tufts University Graduate School of Biomedical SciencesBostonMassachusettsUSA
| | - Gareth R. Howell
- The Jackson LaboratoryBar HarborMaineUSA
- Tufts University Graduate School of Biomedical SciencesBostonMassachusettsUSA
- Graduate School of Biomedical Sciences and EngineeringUniversity of MaineOronoMaineUSA
| | - Erik B. Bloss
- The Jackson LaboratoryBar HarborMaineUSA
- Tufts University Graduate School of Biomedical SciencesBostonMassachusettsUSA
- Graduate School of Biomedical Sciences and EngineeringUniversity of MaineOronoMaineUSA
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42
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Wei M, Yang L, Su F, Liu Y, Zhao X, Luo L, Sun X, Liu S, Dong Z, Zhang Y, Shi YS, Liang J, Zhang C. ABHD6 drives endocytosis of AMPA receptors to regulate synaptic plasticity and learning flexibility. Prog Neurobiol 2024; 233:102559. [PMID: 38159878 DOI: 10.1016/j.pneurobio.2023.102559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/26/2023] [Accepted: 12/06/2023] [Indexed: 01/03/2024]
Abstract
Trafficking of α-Amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors (AMPARs), mediated by AMPAR interacting proteins, enabled neurons to maintain tuning capabilities at rest or active state. α/β-Hydrolase domain-containing 6 (ABHD6), an endocannabinoid hydrolase, was an AMPAR auxiliary subunit found to negatively regulate the surface delivery of AMPARs. While ABHD6 was found to prevent AMPAR tetramerization in endoplasmic reticulum, ABHD6 was also reported to localize at postsynaptic site. Yet, the role of ABHD6 interacting with AMPAR at postsynaptic site, and the physiological significance of ABHD6 regulating AMPAR trafficking remains elusive. Here, we generated the ABHD6 knockout (ABHD6KO) mice and found that deletion of ABHD6 selectively enhanced AMPAR-mediated basal synaptic responses and the surface expression of postsynaptic AMPARs. Furthermore, we found that loss of ABHD6 impaired hippocampal long-term depression (LTD) and synaptic downscaling in hippocampal synapses. AMPAR internalization assays revealed that ABHD6 was essential for neuronal activity-dependent endocytosis of surface AMPARs, which is independent of ABHD6's hydrolase activity. The defects of AMPAR endocytosis and LTD are expressed as deficits in learning flexibility in ABHD6KO mice. Collectively, we demonstrated that ABHD6 is an endocytic accessory protein promoting AMPAR endocytosis, thereby contributes to the formation of LTD, synaptic downscaling and reversal learning.
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Affiliation(s)
- Mengping Wei
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China.
| | - Lei Yang
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Feng Su
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Ying Liu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing 100101, China
| | - Xinyi Zhao
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Lin Luo
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Xinyue Sun
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Sen Liu
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Zhaoqi Dong
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Yong Zhang
- Department of Neurobiology, School of Basic Medical Sciences and Neuroscience Research Institute, Key Lab for Neuroscience, Ministry of Education of China and National Health Commission of the PR China, IDG/McGovern Institute for Brain Research at PKU, Peking University, Beijing 100083, China
| | - Yun Stone Shi
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing 210032, China
| | - Jing Liang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing 100101, China.
| | - Chen Zhang
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China.
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Lee J, Kim SH, Jang DC, Jang M, Bak MS, Shim HG, Lee YS, Kim SJ. Intrinsic plasticity of Purkinje cell serves homeostatic regulation of fear memory. Mol Psychiatry 2024; 29:247-256. [PMID: 38017229 DOI: 10.1038/s41380-023-02320-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 10/26/2023] [Accepted: 11/06/2023] [Indexed: 11/30/2023]
Abstract
Two forms of plasticity, synaptic and intrinsic, are neural substrates for learning and memory. Abnormalities in homeostatic plasticity cause severe neuropsychiatric diseases, such as schizophrenia and autism. This suggests that the balance between synaptic transmission and intrinsic excitability is important for physiological function in the brain. Despite the established role of synaptic plasticity between parallel fiber (PF) and Purkinje cell (PC) in fear memory, its relationship with intrinsic plasticity is not well understood. Here, patch clamp recording revealed depression of intrinsic excitability in PC following auditory fear conditioning (AFC). Depressed excitability balanced long-term potentiation of PF-PC synapse to serve homeostatic regulation of PF-evoked PC firing. We then optogenetically manipulated PC excitability during the early consolidation period resulting in bidirectional regulation of fear memory. Fear conditioning-induced synaptic plasticity was also regulated following optogenetic manipulation. These results propose intrinsic plasticity in PC as a novel mechanism of fear memory and elucidate that decreased intrinsic excitability in PC counterbalances PF-PC synaptic potentiation to maintain fear memory in a normal range.
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Affiliation(s)
- Jaegeon Lee
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Seung Ha Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Dong Cheol Jang
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Mirae Jang
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Myeong Seong Bak
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Hyun Geun Shim
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Yong-Seok Lee
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea
- Memory Network Medical Research Center, Neuroscience Research Institute, Wide River Institute of Immunology, Seoul National University College of Medicine, Seoul, 03080, Korea
| | - Sang Jeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Korea.
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Korea.
- Memory Network Medical Research Center, Neuroscience Research Institute, Wide River Institute of Immunology, Seoul National University College of Medicine, Seoul, 03080, Korea.
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44
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Ma Y, Bendl J, Hartley BJ, Fullard JF, Abdelaal R, Ho SM, Kosoy R, Gochman P, Rapoport J, Hoffman GE, Brennand KJ, Roussos P. Activity-Dependent Transcriptional Program in NGN2+ Neurons Enriched for Genetic Risk for Brain-Related Disorders. Biol Psychiatry 2024; 95:187-198. [PMID: 37454787 PMCID: PMC10787819 DOI: 10.1016/j.biopsych.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 06/07/2023] [Accepted: 07/09/2023] [Indexed: 07/18/2023]
Abstract
BACKGROUND Converging evidence from large-scale genetic and postmortem studies highlights the role of aberrant neurotransmission and genetic regulation in brain-related disorders. However, identifying neuronal activity-regulated transcriptional programs in the human brain and understanding how changes contribute to disease remain challenging. METHODS To better understand how the activity-dependent regulome contributes to risk for brain-related disorders, we profiled the transcriptomic and epigenomic changes following neuronal depolarization in human induced pluripotent stem cell-derived glutamatergic neurons (NGN2) from 6 patients with schizophrenia and 5 control participants. RESULTS Multiomic data integration associated global patterns of chromatin accessibility with gene expression and identified enhancer-promoter interactions in glutamatergic neurons. Within 1 hour of potassium chloride-induced depolarization, independent of diagnosis, glutamatergic neurons displayed substantial activity-dependent changes in the expression of genes regulating synaptic function. Depolarization-induced changes in the regulome revealed significant heritability enrichment for schizophrenia and Parkinson's disease, adding to mounting evidence that sequence variation within activation-dependent regulatory elements contributes to the genetic risk for brain-related disorders. Gene coexpression network analysis elucidated interactions among activity-dependent and disease-associated genes and pointed to a key driver (NAV3) that interacted with multiple genes involved in axon guidance. CONCLUSIONS Overall, we demonstrated that deciphering the activity-dependent regulome in glutamatergic neurons reveals novel targets for advanced diagnosis and therapy.
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Affiliation(s)
- Yixuan Ma
- Center for Disease Neurogenomics, Icahn School of Medicine at Mount Sinai, New York, New York; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Genetics and Genomic Science, Icahn School of Medicine at Mount Sinai, New York, New York; Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jaroslav Bendl
- Center for Disease Neurogenomics, Icahn School of Medicine at Mount Sinai, New York, New York; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Genetics and Genomic Science, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Brigham J Hartley
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York; Black Family Stem Cell Institute, New York, New York
| | - John F Fullard
- Center for Disease Neurogenomics, Icahn School of Medicine at Mount Sinai, New York, New York; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Genetics and Genomic Science, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Rawan Abdelaal
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York; Black Family Stem Cell Institute, New York, New York
| | - Seok-Man Ho
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York; Black Family Stem Cell Institute, New York, New York
| | - Roman Kosoy
- Center for Disease Neurogenomics, Icahn School of Medicine at Mount Sinai, New York, New York; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Genetics and Genomic Science, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Peter Gochman
- Childhood Psychiatry Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Judith Rapoport
- Childhood Psychiatry Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Gabriel E Hoffman
- Center for Disease Neurogenomics, Icahn School of Medicine at Mount Sinai, New York, New York; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Genetics and Genomic Science, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Kristen J Brennand
- Center for Disease Neurogenomics, Icahn School of Medicine at Mount Sinai, New York, New York; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York; Black Family Stem Cell Institute, New York, New York.
| | - Panos Roussos
- Center for Disease Neurogenomics, Icahn School of Medicine at Mount Sinai, New York, New York; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York; Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Genetics and Genomic Science, Icahn School of Medicine at Mount Sinai, New York, New York; Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York; Mental Illness Research Education and Clinical Center, James J. Peters VA Medical Center, Bronx, New York.
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45
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Stengl M, Schneider AC. Contribution of membrane-associated oscillators to biological timing at different timescales. Front Physiol 2024; 14:1243455. [PMID: 38264332 PMCID: PMC10803594 DOI: 10.3389/fphys.2023.1243455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 12/12/2023] [Indexed: 01/25/2024] Open
Abstract
Environmental rhythms such as the daily light-dark cycle selected for endogenous clocks. These clocks predict regular environmental changes and provide the basis for well-timed adaptive homeostasis in physiology and behavior of organisms. Endogenous clocks are oscillators that are based on positive feedforward and negative feedback loops. They generate stable rhythms even under constant conditions. Since even weak interactions between oscillators allow for autonomous synchronization, coupling/synchronization of oscillators provides the basis of self-organized physiological timing. Amongst the most thoroughly researched clocks are the endogenous circadian clock neurons in mammals and insects. They comprise nuclear clockworks of transcriptional/translational feedback loops (TTFL) that generate ∼24 h rhythms in clock gene expression entrained to the environmental day-night cycle. It is generally assumed that this TTFL clockwork drives all circadian oscillations within and between clock cells, being the basis of any circadian rhythm in physiology and behavior of organisms. Instead of the current gene-based hierarchical clock model we provide here a systems view of timing. We suggest that a coupled system of autonomous TTFL and posttranslational feedback loop (PTFL) oscillators/clocks that run at multiple timescales governs adaptive, dynamic homeostasis of physiology and behavior. We focus on mammalian and insect neurons as endogenous oscillators at multiple timescales. We suggest that neuronal plasma membrane-associated signalosomes constitute specific autonomous PTFL clocks that generate localized but interlinked oscillations of membrane potential and intracellular messengers with specific endogenous frequencies. In each clock neuron multiscale interactions of TTFL and PTFL oscillators/clocks form a temporally structured oscillatory network with a common complex frequency-band comprising superimposed multiscale oscillations. Coupling between oscillator/clock neurons provides the next level of complexity of an oscillatory network. This systemic dynamic network of molecular and cellular oscillators/clocks is suggested to form the basis of any physiological homeostasis that cycles through dynamic homeostatic setpoints with a characteristic frequency-band as hallmark. We propose that mechanisms of homeostatic plasticity maintain the stability of these dynamic setpoints, whereas Hebbian plasticity enables switching between setpoints via coupling factors, like biogenic amines and/or neuropeptides. They reprogram the network to a new common frequency, a new dynamic setpoint. Our novel hypothesis is up for experimental challenge.
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Affiliation(s)
- Monika Stengl
- Department of Biology, Animal Physiology/Neuroethology, University of Kassel, Kassel, Germany
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Austin TT, Thomas CL, Warren B. Auditory robustness and resilience in the aging auditory system of the desert locust. Neurobiol Aging 2024; 133:39-50. [PMID: 37913625 DOI: 10.1016/j.neurobiolaging.2023.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/19/2023] [Accepted: 09/19/2023] [Indexed: 11/03/2023]
Abstract
After overexposure to loud music, we experience a decrease in our ability to hear (robustness), which usually recovers (resilience). Here, we exploited the amenable auditory system of the desert locust, Schistocerca gregaria, to measure how robustness and resilience depend on age. We found that gene expression changes are dominated by age as opposed to noise exposure. We measured sound-evoked nerve activity for young and aged locusts directly, after 24 hours and 48 hours after noise exposure. We found that both young and aged locusts recovered their auditory nerve function over 48 hours. We also measured the sound-evoked transduction current in individual auditory neurons, and although the transduction current magnitude recovered in the young locusts after noise exposure, it failed to recover in the aged locusts. A plastic mechanism compensates for the decreased transduction current in aged locusts. We suggest key genes upregulated in young noise-exposed locusts that mediate robustness to noise exposure and find potential candidates responsible for compensatory mechanisms in the auditory neurons of aged noise-exposed locusts.
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Affiliation(s)
- Thomas T Austin
- Neurogenetics Group, College of Life Sciences, University of Leicester, Leicester LE1 7RH, UK
| | - Christian L Thomas
- Neurogenetics Group, College of Life Sciences, University of Leicester, Leicester LE1 7RH, UK
| | - Ben Warren
- Neurogenetics Group, College of Life Sciences, University of Leicester, Leicester LE1 7RH, UK.
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47
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Thompson AC, Aizenman CD. Characterization of Na + currents regulating intrinsic excitability of optic tectal neurons. Life Sci Alliance 2024; 7:e202302232. [PMID: 37918964 PMCID: PMC10622587 DOI: 10.26508/lsa.202302232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023] Open
Abstract
Developing neurons adapt their intrinsic excitability to maintain stable output despite changing synaptic input. The mechanisms behind this process remain unclear. In this study, we examined Xenopus optic tectal neurons and found that the expressions of Nav1.1 and Nav1.6 voltage-gated Na+ channels are regulated during changes in intrinsic excitability, both during development and becsuse of changes in visual experience. Using whole-cell electrophysiology, we demonstrate the existence of distinct, fast, persistent, and resurgent Na+ currents in the tectum, and show that these Na+ currents are co-regulated with changes in Nav channel expression. Using antisense RNA to suppress the expression of specific Nav subunits, we found that up-regulation of Nav1.6 expression, but not Nav1.1, was necessary for experience-dependent increases in Na+ currents and intrinsic excitability. Furthermore, this regulation was also necessary for normal development of sensory guided behaviors. These data suggest that the regulation of Na+ currents through the modulation of Nav1.6 expression, and to a lesser extent Nav1.1, plays a crucial role in controlling the intrinsic excitability of tectal neurons and guiding normal development of the tectal circuitry.
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Affiliation(s)
- Adrian C Thompson
- https://ror.org/05gq02987 Department of Neuroscience, Brown University, Providence, RI, USA
| | - Carlos D Aizenman
- https://ror.org/05gq02987 Department of Neuroscience, Brown University, Providence, RI, USA
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48
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Sohn MN, Brown JC, Sharma P, Ziemann U, McGirr A. Pharmacological adjuncts and transcranial magnetic stimulation-induced synaptic plasticity: a systematic review. J Psychiatry Neurosci 2024; 49:E59-E76. [PMID: 38359933 PMCID: PMC10890793 DOI: 10.1503/jpn.230090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 10/23/2023] [Accepted: 11/08/2023] [Indexed: 02/17/2024] Open
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) is a noninvasive neurostimulation modality that has been used to study human synaptic plasticity. Leveraging work in ex vivo preparations, mechanistically informed pharmacological adjuncts to TMS have been used to improve our fundamental understanding of TMS-induced synaptic plasticity. METHODS We systematically reviewed the literature pairing pharmacological adjuncts with TMS plasticity-induction protocols in humans. We searched MEDLINE, PsycINFO, and Embase from 2013 to Mar. 10, 2023. Studies published before 2013 were extracted from a previous systematic review. We included studies using repetitive TMS, theta-burst stimulation, paired associative stimulation, and quadripulse stimulation paradigms in healthy and clinical populations. RESULTS Thirty-six studies met our inclusion criteria (28 in healthy and 8 in clinical populations). Most pharmacological agents have targeted the glutamatergic N-methyl-d-aspartate (NMDA; 15 studies) or dopamine receptors (13 studies). The NMDA receptor is necessary for TMS-induced plasticity; however, sufficiency has not been shown across protocols. Dopaminergic modulation of TMS-induced plasticity appears to be dose-dependent. The GABAergic, cholinergic, noradrenergic, and serotonergic neurotransmitter systems have small evidence bases supporting modulation of TMS-induced plasticity, as do voltage-gated calcium and sodium channels. Studies in clinical populations suggest that pharmacological adjuncts to TMS may rescue motor cortex plasticity, with implications for therapeutic applications of TMS and a promising clinical trial in depression. LIMITATIONS This review is limited by the predominance in the literature of studies with small sample sizes and crossover designs. CONCLUSION Pharmacologically enhanced TMS largely parallels findings from ex vivo preparations. As this area expands and novel targets are tested, adequately powered samples in healthy and clinical populations will inform the mechanisms of TMS-induced plasticity in health and disease.
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Affiliation(s)
- Myren N Sohn
- From the Hotchkiss Brain Institute, University of Calgary, Calgary, Alta., Canada (Sohn, McGirr); the Department of Psychiatry, University of Calgary, Alta., Canada (Sohn, McGirr); the Mathison Centre for Mental Health Research and Education, Calgary, Alta., Canada (Sohn, McGirr); the McLean Hospital, Division of Neurotherapeutics, Belmont, Mass., USA (Brown, Sharma); the Department of Psychiatry, Harvard Medical School, Boston, Mass., USA (Brown); the Department of Neurology & Stroke, Eberhard-Karls University, Tübingen, Germany (Ziemann); and the Hertie-Institute for Clinical Brain Research, Eberhard-Karls University, Tübingen, Germany (Ziemann)
| | - Joshua C Brown
- From the Hotchkiss Brain Institute, University of Calgary, Calgary, Alta., Canada (Sohn, McGirr); the Department of Psychiatry, University of Calgary, Alta., Canada (Sohn, McGirr); the Mathison Centre for Mental Health Research and Education, Calgary, Alta., Canada (Sohn, McGirr); the McLean Hospital, Division of Neurotherapeutics, Belmont, Mass., USA (Brown, Sharma); the Department of Psychiatry, Harvard Medical School, Boston, Mass., USA (Brown); the Department of Neurology & Stroke, Eberhard-Karls University, Tübingen, Germany (Ziemann); and the Hertie-Institute for Clinical Brain Research, Eberhard-Karls University, Tübingen, Germany (Ziemann)
| | - Prayushi Sharma
- From the Hotchkiss Brain Institute, University of Calgary, Calgary, Alta., Canada (Sohn, McGirr); the Department of Psychiatry, University of Calgary, Alta., Canada (Sohn, McGirr); the Mathison Centre for Mental Health Research and Education, Calgary, Alta., Canada (Sohn, McGirr); the McLean Hospital, Division of Neurotherapeutics, Belmont, Mass., USA (Brown, Sharma); the Department of Psychiatry, Harvard Medical School, Boston, Mass., USA (Brown); the Department of Neurology & Stroke, Eberhard-Karls University, Tübingen, Germany (Ziemann); and the Hertie-Institute for Clinical Brain Research, Eberhard-Karls University, Tübingen, Germany (Ziemann)
| | - Ulf Ziemann
- From the Hotchkiss Brain Institute, University of Calgary, Calgary, Alta., Canada (Sohn, McGirr); the Department of Psychiatry, University of Calgary, Alta., Canada (Sohn, McGirr); the Mathison Centre for Mental Health Research and Education, Calgary, Alta., Canada (Sohn, McGirr); the McLean Hospital, Division of Neurotherapeutics, Belmont, Mass., USA (Brown, Sharma); the Department of Psychiatry, Harvard Medical School, Boston, Mass., USA (Brown); the Department of Neurology & Stroke, Eberhard-Karls University, Tübingen, Germany (Ziemann); and the Hertie-Institute for Clinical Brain Research, Eberhard-Karls University, Tübingen, Germany (Ziemann)
| | - Alexander McGirr
- From the Hotchkiss Brain Institute, University of Calgary, Calgary, Alta., Canada (Sohn, McGirr); the Department of Psychiatry, University of Calgary, Alta., Canada (Sohn, McGirr); the Mathison Centre for Mental Health Research and Education, Calgary, Alta., Canada (Sohn, McGirr); the McLean Hospital, Division of Neurotherapeutics, Belmont, Mass., USA (Brown, Sharma); the Department of Psychiatry, Harvard Medical School, Boston, Mass., USA (Brown); the Department of Neurology & Stroke, Eberhard-Karls University, Tübingen, Germany (Ziemann); and the Hertie-Institute for Clinical Brain Research, Eberhard-Karls University, Tübingen, Germany (Ziemann)
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O'Neill KM, Anderson ED, Mukherjee S, Gandu S, McEwan SA, Omelchenko A, Rodriguez AR, Losert W, Meaney DF, Babadi B, Firestein BL. Time-dependent homeostatic mechanisms underlie brain-derived neurotrophic factor action on neural circuitry. Commun Biol 2023; 6:1278. [PMID: 38110605 PMCID: PMC10728104 DOI: 10.1038/s42003-023-05638-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 11/27/2023] [Indexed: 12/20/2023] Open
Abstract
Plasticity and homeostatic mechanisms allow neural networks to maintain proper function while responding to physiological challenges. Despite previous work investigating morphological and synaptic effects of brain-derived neurotrophic factor (BDNF), the most prevalent growth factor in the central nervous system, how exposure to BDNF manifests at the network level remains unknown. Here we report that BDNF treatment affects rodent hippocampal network dynamics during development and recovery from glutamate-induced excitotoxicity in culture. Importantly, these effects are not obvious when traditional activity metrics are used, so we delve more deeply into network organization, functional analyses, and in silico simulations. We demonstrate that BDNF partially restores homeostasis by promoting recovery of weak and medium connections after injury. Imaging and computational analyses suggest these effects are caused by changes to inhibitory neurons and connections. From our in silico simulations, we find that BDNF remodels the network by indirectly strengthening weak excitatory synapses after injury. Ultimately, our findings may explain the difficulties encountered in preclinical and clinical trials with BDNF and also offer information for future trials to consider.
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Affiliation(s)
- Kate M O'Neill
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, USA
- Biomedical Engineering Graduate Program, Rutgers University, Piscataway, NJ, USA
- Institute for Physical Science & Technology, University of Maryland, College Park, MD, USA
| | - Erin D Anderson
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Shoutik Mukherjee
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, USA
| | - Srinivasa Gandu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, USA
- Cell and Developmental Biology Graduate Program, Rutgers University, Piscataway, NJ, USA
| | - Sara A McEwan
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, USA
- Neuroscience Graduate Program, Rutgers University, Piscataway, NJ, USA
| | - Anton Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, USA
- Neuroscience Graduate Program, Rutgers University, Piscataway, NJ, USA
| | - Ana R Rodriguez
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, USA
- Biomedical Engineering Graduate Program, Rutgers University, Piscataway, NJ, USA
| | - Wolfgang Losert
- Department of Physics, University of Maryland, College Park, MD, USA
- Institute for Physical Science & Technology, University of Maryland, College Park, MD, USA
| | - David F Meaney
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Behtash Babadi
- Department of Electrical and Computer Engineering, University of Maryland, College Park, MD, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, USA.
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50
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Janz P, Knoflach F, Bleicher K, Belli S, Biemans B, Schnider P, Ebeling M, Grundschober C, Benekareddy M. Selective oxytocin receptor activation prevents prefrontal circuit dysfunction and social behavioral alterations in response to chronic prefrontal cortex activation in male rats. Front Cell Neurosci 2023; 17:1286552. [PMID: 38145283 PMCID: PMC10745491 DOI: 10.3389/fncel.2023.1286552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/08/2023] [Indexed: 12/26/2023] Open
Abstract
Introduction Social behavioral changes are a hallmark of several neurodevelopmental and neuropsychiatric conditions, nevertheless the underlying neural substrates of such dysfunction remain poorly understood. Building evidence points to the prefrontal cortex (PFC) as one of the key brain regions that orchestrates social behavior. We used this concept with the aim to develop a translational rat model of social-circuit dysfunction, the chronic PFC activation model (CPA). Methods Chemogenetic designer receptor hM3Dq was used to induce chronic activation of the PFC over 10 days, and the behavioral and electrophysiological signatures of prolonged PFC hyperactivity were evaluated. To test the sensitivity of this model to pharmacological interventions on longer timescales, and validate its translational potential, the rats were treated with our novel highly selective oxytocin receptor (OXTR) agonist RO6958375, which is not activating the related vasopressin V1a receptor. Results CPA rats showed reduced sociability in the three-chamber sociability test, and a concomitant decrease in neuronal excitability and synaptic transmission within the PFC as measured by electrophysiological recordings in acute slice preparation. Sub-chronic treatment with a low dose of the novel OXTR agonist following CPA interferes with the emergence of PFC circuit dysfunction, abnormal social behavior and specific transcriptomic changes. Discussion These results demonstrate that sustained PFC hyperactivity modifies circuit characteristics and social behaviors in ways that can be modulated by selective OXTR activation and that this model may be used to understand the circuit recruitment of prosocial therapies in drug discovery.
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Affiliation(s)
- Philipp Janz
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Frederic Knoflach
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Konrad Bleicher
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Sara Belli
- Roche Pharma Research and Early Development, Pharmaceutical Science, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Barbara Biemans
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Patrick Schnider
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Martin Ebeling
- Roche Pharma Research and Early Development, Pharmaceutical Science, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Christophe Grundschober
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
| | - Madhurima Benekareddy
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche AG, Basel, Switzerland
- Calico Life Sciences, South San Francisco, CA, United States
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