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Stetak AL, Grenal T, Lenninger Z, Knight KM, Doser RL, Hoerndli FJ. A Necessary Role for PKC-2 and TPA-1 in Olfactory Memory and Synaptic AMPAR Trafficking in Caenorhabditis elegans. J Neurosci 2024; 44:e1120232024. [PMID: 38238075 PMCID: PMC10919255 DOI: 10.1523/jneurosci.1120-23.2024] [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: 06/16/2023] [Revised: 01/09/2024] [Accepted: 01/11/2024] [Indexed: 01/25/2024] Open
Abstract
Protein kinase C (PKC) functions are essential for synaptic plasticity, learning, and memory. However, the roles of specific members of the PKC family in synaptic function, learning, and memory are poorly understood. Here, we investigated the role of individual PKC homologs for synaptic plasticity in Caenorhabditis elegans and found a differential role for pkc-2 and tpa-1, but not pkc-1 and pkc-3 in associative olfactory learning and memory. More specifically we show that PKC-2 is essential for associative learning and TPA-1 for short-term associative memory (STAM). Using endogenous labeling and cell-specific rescues, we show that TPA-1 and PKC-2 are required in AVA for their functions. Previous studies demonstrated that olfactory learning and memory in C. elegans are tied to proper synaptic content and trafficking of AMPA-type ionotropic glutamate receptor homolog GLR-1 in the AVA command interneurons. Therefore, we quantified synaptic content, transport, and delivery of GLR-1 in AVA and showed that loss of pkc-2 and tpa-1 leads to decreased transport and delivery but only a subtle decrease in GLR-1 levels at synapses. AVA-specific expression of both PKC-2 and TPA-1 rescued these defects. Finally, genetic epistasis showed that PKC-2 and TPA-1 likely act in the same pathway to control GLR-1 transport and delivery, while regulating different aspects of olfactory learning and STAM. Thus, our data tie together cell-specific functions of 2 PKCs to neuronal and behavioral outcomes in C. elegans, enabling comparative approaches to understand the evolutionarily conserved role of PKC in synaptic plasticity, learning, and memory.
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Affiliation(s)
- Attila L Stetak
- Division of Molecular Neuroscience, Department of Biomedicine, University of Basel, 4055 Basel, Switzerland
- University Psychiatric Clinics, University of Basel, 4002 Basel, Switzerland
| | - Thomas Grenal
- Division of Molecular Neuroscience, Department of Biomedicine, University of Basel, 4055 Basel, Switzerland
| | - Zephyr Lenninger
- Departments of Biomedical Science, Colorado State University, Fort Collins, Colorado 80523
| | - Kaz M Knight
- Departments of Biomedical Science, Colorado State University, Fort Collins, Colorado 80523
| | - Rachel L Doser
- Departments of Biomedical Science, Colorado State University, Fort Collins, Colorado 80523
- Health and Exercise Sciences, Colorado State University, Fort Collins, Colorado 80523
| | - Frederic J Hoerndli
- Departments of Biomedical Science, Colorado State University, Fort Collins, Colorado 80523
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Karoglu-Eravsar ET, Tuz-Sasik MU, Karaduman A, Keskus AG, Arslan-Ergul A, Konu O, Kafaligonul H, Adams MM. Long-Term Acetylcholinesterase Depletion Alters the Levels of Key Synaptic Proteins while Maintaining Neuronal Markers in the Aging Zebrafish (Danio rerio) Brain. Gerontology 2023; 69:1424-1436. [PMID: 37793352 PMCID: PMC10711754 DOI: 10.1159/000534343] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 09/25/2023] [Indexed: 10/06/2023] Open
Abstract
INTRODUCTION Interventions targeting cholinergic neurotransmission like acetylcholinesterase (AChE) inhibition distinguish potential mechanisms to delay age-related impairments and attenuate deficits related to neurodegenerative diseases. However, the chronic effects of these interventions are not well described. METHODS In the current study, global levels of cholinergic, cellular, synaptic, and inflammation-mediating proteins were assessed within the context of aging and chronic reduction of AChE activity. Long-term depletion of AChE activity was induced by using a mutant zebrafish line, and they were compared with the wildtype group at young and old ages. RESULTS Results demonstrated that AChE activity was lower in both young and old mutants, and this decrease coincided with a reduction in ACh content. Additionally, an overall age-related reduction in AChE activity and the AChE/ACh ratio was observed, and this decline was more prominent in wildtype groups. The levels of an immature neuronal marker were upregulated in mutants, while a glial marker showed an overall reduction. Mutants had preserved levels of inhibitory and presynaptic elements with aging, whereas glutamate receptor subunit levels declined. CONCLUSION Long-term AChE activity depletion induces synaptic and cellular alterations. These data provide further insights into molecular targets and adaptive responses following the long-term reduction of AChE activity that was also targeted pharmacologically to treat neurodegenerative diseases in human subjects.
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Affiliation(s)
- Elif Tugce Karoglu-Eravsar
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey
- National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology (UNAM), Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
- Department of Psychology, Selcuk University, Konya, Turkey
| | - Melek Umay Tuz-Sasik
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey
- National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology (UNAM), Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
| | - Aysenur Karaduman
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Ayse Gokce Keskus
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey
- National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology (UNAM), Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
| | - Ayca Arslan-Ergul
- National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology (UNAM), Bilkent University, Ankara, Turkey
| | - Ozlen Konu
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey
- National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology (UNAM), Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey
| | - Hulusi Kafaligonul
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey
- National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology (UNAM), Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Michelle M. Adams
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey
- National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology (UNAM), Bilkent University, Ankara, Turkey
- Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
- Department of Psychology, Bilkent University, Ankara, Turkey
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Effect of Sinapic Acid on Scopolamine-Induced Learning and Memory Impairment in SD Rats. Brain Sci 2023; 13:brainsci13030427. [PMID: 36979237 PMCID: PMC10046676 DOI: 10.3390/brainsci13030427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 03/06/2023] Open
Abstract
The seriousness of the diseases caused by aging have recently gained attention. Alzheimer’s disease (AD), a chronic neurodegenerative disease, accounts for 60–80% of senile dementia cases. Continuous research is being conducted on the cause of Alzheimer’s disease, and it is believed to include complex factors, such as genetic factors, the accumulation of amyloid beta plaques, a tangle of tau protein, oxidative stress, cholinergic dysfunction, neuroinflammation, and cell death. Sinapic acid is a hydroxycinnamic acid found in plant families, such as oranges, grapefruit, cranberry, mustard seeds, and rapeseeds. It exhibits various biological activities, including anti-inflammatory, anti-oxidant, anti-cancer, and anti-depressant effects. Sinapic acid is an acetylcholine esterase inhibitor that can be applied to the treatment of dementia caused by Alzheimer’s disease and Parkinson’s disease. However, electrophysiological studies on the effects of sinapic acid on memory and learning must still be conducted. Therefore, it was confirmed that sinapic acid was effective in long-term potentiation (LTP) using organotypic hippocampal segment tissue. In addition, the effect on scopolamine-induced learning and memory impairment was measured by oral administration of sinapic acid 10 mg/kg/day for 14 days, and behavioral experiments related to short-term and long-term spatial memory and avoidance memory were conducted. Sinapic acid increased the activity of the field excitatory postsynaptic potential (fEPSP) in a dose-dependent manner after TBS, and restored fEPSP activity in the CA1 region suppressed by scopolamine. The scopolamine-induced learning and memory impairment group showed lower results than the control group in the Y-maze, Passive avoidance (PA), and Morris water maze (MWM) experiments. Sinapic acid improved avoidance memory, short and long-term spatial recognition learning, and memory. In addition, sinapic acid weakened the inhibition of the brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB) and the activation of prostaglandin-endoperoxide synthase 2 (COX-2) and interleukin 1 beta (IL-1β) induced by scopolamine in the hippocampus. These results show that sinapic acid is effective in restoring LTP and cognitive impairment induced by the cholinergic receptor blockade. Moreover, it showed the effect of alleviating the reduction in scopolamine-induced BDNF and TrkB, and alleviated neuroinflammatory effects by inhibiting the increase in COX-2 and IL-1β. Therefore, we showed that sinapic acid has potential as a treatment for neurodegenerative cognitive impairment.
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Plasticity of visual evoked potentials in patients with neurofibromatosis type 1. Clin Neurophysiol 2022; 142:220-227. [DOI: 10.1016/j.clinph.2022.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 08/01/2022] [Accepted: 08/10/2022] [Indexed: 11/17/2022]
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Li KT, He X, Zhou G, Yang J, Li T, Hu H, Ji D, Zhou C, Ma H. Rational designing of oscillatory rhythmicity for memory rescue in plasticity-impaired learning networks. Cell Rep 2022; 39:110678. [PMID: 35417714 DOI: 10.1016/j.celrep.2022.110678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/19/2022] [Accepted: 03/22/2022] [Indexed: 12/15/2022] Open
Abstract
In the brain, oscillatory strength embedded in network rhythmicity is important for processing experiences, and this process is disrupted in certain psychiatric disorders. The use of rhythmic network stimuli can change these oscillations and has shown promise in terms of improving cognitive function, although the underlying mechanisms are poorly understood. Here, we combine a two-layer learning model, with experiments involving genetically modified mice, that provides precise control of experience-driven oscillations by manipulating long-term potentiation of excitatory synapses onto inhibitory interneurons (LTPE→I). We find that, in the absence of LTPE→I, impaired network dynamics and memory are rescued by activating inhibitory neurons to augment the power in theta and gamma frequencies, which prevents network overexcitation with less inhibitory rebound. In contrast, increasing either theta or gamma power alone was less effective. Thus, inducing network changes at dual frequencies is involved in memory encoding, indicating a potentially feasible strategy for optimizing network-stimulating therapies.
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Affiliation(s)
- Kwan Tung Li
- Department of Physics, Centre for Nonlinear Studies, Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Hong Kong, China
| | - Xingzhi He
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; Liangzhu Laboratory, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Guangjun Zhou
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; Liangzhu Laboratory, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Jing Yang
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; Liangzhu Laboratory, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Tao Li
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; Liangzhu Laboratory, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Hailan Hu
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; Liangzhu Laboratory, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China; Research Units for Emotion and Emotion disorders, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Daoyun Ji
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Changsong Zhou
- Department of Physics, Centre for Nonlinear Studies, Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Hong Kong, China; Department of Physics, Zhejiang University, Hangzhou 310027, China.
| | - Huan Ma
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; Liangzhu Laboratory, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China; Research Units for Emotion and Emotion disorders, Chinese Academy of Medical Sciences, Beijing 100730, China.
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He X, Wang Y, Zhou G, Yang J, Li J, Li T, Hu H, Ma H. A Critical Role for γCaMKII in Decoding NMDA Signaling to Regulate AMPA Receptors in Putative Inhibitory Interneurons. Neurosci Bull 2022; 38:916-926. [PMID: 35290589 PMCID: PMC9352831 DOI: 10.1007/s12264-022-00840-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/20/2021] [Indexed: 12/24/2022] Open
Abstract
CaMKII is essential for long-term potentiation (LTP), a process in which synaptic strength is increased following the acquisition of information. Among the four CaMKII isoforms, γCaMKII is the one that mediates the LTP of excitatory synapses onto inhibitory interneurons (LTPE→I). However, the molecular mechanism underlying how γCaMKII mediates LTPE→I remains unclear. Here, we show that γCaMKII is highly enriched in cultured hippocampal inhibitory interneurons and opts to be activated by higher stimulating frequencies in the 10-30 Hz range. Following stimulation, γCaMKII is translocated to the synapse and becomes co-localized with the postsynaptic protein PSD-95. Knocking down γCaMKII prevents the chemical LTP-induced phosphorylation and trafficking of AMPA receptors (AMPARs) in putative inhibitory interneurons, which are restored by overexpression of γCaMKII but not its kinase-dead form. Taken together, these data suggest that γCaMKII decodes NMDAR-mediated signaling and in turn regulates AMPARs for expressing LTP in inhibitory interneurons.
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Affiliation(s)
- Xingzhi He
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Yang Wang
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Guangjun Zhou
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Jing Yang
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Jiarui Li
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Tao Li
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Hailan Hu
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China
- Research Units for Emotion and Emotion disorders, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Huan Ma
- Department of Neurobiology, Affiliated Mental Health Center and Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, 310058, China.
- Research Units for Emotion and Emotion disorders, Chinese Academy of Medical Sciences, Beijing, 100730, China.
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Watson JF, Pinggera A, Ho H, Greger IH. AMPA receptor anchoring at CA1 synapses is determined by N-terminal domain and TARP γ8 interactions. Nat Commun 2021; 12:5083. [PMID: 34426577 PMCID: PMC8382838 DOI: 10.1038/s41467-021-25281-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 08/02/2021] [Indexed: 12/30/2022] Open
Abstract
AMPA receptor (AMPAR) abundance and positioning at excitatory synapses regulates the strength of transmission. Changes in AMPAR localisation can enact synaptic plasticity, allowing long-term information storage, and is therefore tightly controlled. Multiple mechanisms regulating AMPAR synaptic anchoring have been described, but with limited coherence or comparison between reports, our understanding of this process is unclear. Here, combining synaptic recordings from mouse hippocampal slices and super-resolution imaging in dissociated cultures, we compare the contributions of three AMPAR interaction domains controlling transmission at hippocampal CA1 synapses. We show that the AMPAR C-termini play only a modulatory role, whereas the extracellular N-terminal domain (NTD) and PDZ interactions of the auxiliary subunit TARP γ8 are both crucial, and each is sufficient to maintain transmission. Our data support a model in which γ8 accumulates AMPARs at the postsynaptic density, where the NTD further tunes their positioning. This interplay between cytosolic (TARP γ8) and synaptic cleft (NTD) interactions provides versatility to regulate synaptic transmission and plasticity.
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Affiliation(s)
- Jake F Watson
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
- IST Austria, Am Campus 1, Klosterneuburg, Austria
| | - Alexandra Pinggera
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
| | - Hinze Ho
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Ingo H Greger
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, United Kingdom.
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Karoglu-Eravsar ET, Tuz-Sasik MU, Adams MM. Short-term dietary restriction maintains synaptic plasticity whereas short-term overfeeding alters cellular dynamics in the aged brain: evidence from the zebrafish model organism. Neurobiol Aging 2021; 106:169-182. [PMID: 34284260 DOI: 10.1016/j.neurobiolaging.2021.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 05/06/2021] [Accepted: 06/12/2021] [Indexed: 12/12/2022]
Abstract
Increased caloric intake (OF) impairs quality of life causing comorbidities with other diseases and cognitive deficits, whereas dietary restriction (DR) increases healthspan by preventing age-related deteriorations. To understand the effects of these opposing dietary regimens on the cellular and synaptic dynamics during brain aging, the zebrafish model, which shows gradual aging like mammals, was utilized. Global changes in cellular and synaptic markers with respect to age and a 12 week dietary regimen of OF and DR demonstrated that aging reduces the levels of the glutamate receptor subunits, GLUR2/3, inhibitory synaptic clustering protein, GEP, synaptic vesicle protein, SYP, and early-differentiated neuronal marker, HuC. DR significantly elevates levels of glutamate receptor subunits, GLUR2/3, and NMDA clustering protein, PSD95, levels, while OF subtly increases the level of the neuronal protein, DCAMKL1. These data suggest that decreased caloric intake within the context of aging has more robust effects on synapses than cellular proteins, whereas OF alters cellular dynamics. Thus, patterns like these should be taken into account for possible translation to human subjects.
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Affiliation(s)
- Elif Tugce Karoglu-Eravsar
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey; Department of Psychology, Selcuk University, Konya, Turkey
| | - Melek Umay Tuz-Sasik
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey
| | - Michelle M Adams
- Interdisciplinary Program in Neuroscience, Aysel Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey; National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, Turkey; Department of Molecular Biology and Genetics, Zebrafish Facility, Bilkent University, Ankara, Turkey; Department of Psychology, Bilkent University, Ankara, Turkey.
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9
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Park HS, Hwang ES, Choi GY, Kim HB, Park KS, Sul JY, Hwang Y, Choi GW, Kim BI, Park H, Maeng S, Park JH. Sulforaphane enhances long-term potentiation and ameliorate scopolamine-induced memory impairment. Physiol Behav 2021; 238:113467. [PMID: 34033847 DOI: 10.1016/j.physbeh.2021.113467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 01/04/2023]
Abstract
Increases in human life expectancy have led to increases in the prevalence of senile dementia and neurodegenerative diseases. This is a major problem because there are no curative treatments for these diseases, and patients with unmanaged cognitive and neurodegenerative symptoms experience many social problems. Sulforaphane is a type of organosulfur compound known as an isothiocyanate. It is derived from glucoraphanin, a compound found in cruciferous vegetables such as broccoli, brussels sprouts, and cabbages, via an enzymatic reaction that is triggered by plant damage (e.g., chewing). Sulforaphane exhibits activity against cancer, inflammation, depression, and severe cardiac diseases. It can also alleviate oxidative stress and neural dysfunction in the brain. However, there is insufficient knowledge about the electrophysiological and behavioral basis of the effects of sulforaphane on learning and memory. Therefore, we evaluated whether acute sulforaphane administration affected long-term potentiation (LTP) in organotypic cultured rat hippocampal tissues. We also measured the effect of sulforaphane on the performance of three behavioral tests, the Y-maze test, the passive avoidance test, and the Morris water maze, which assess short-term memory, avoidance memory, and short and long-term spatial memory, respectively. We found that sulforaphane increased the total field excitatory postsynaptic potential (fEPSP) in a dose-dependent manner after high frequency stimulation and attenuated scopolamine-induced interference of the fEPSP in the hippocampal CA1 area. Sulforaphane also restored cognitive function and inhibited memory impairment as indicated by the alleviation of the negative neurological effects of scopolamine, i.e, a lowered ratio of spontaneous alternation in the Y-maze, a reduced step-through latency in the passive avoidance test, and an increased navigation time in the Morris water maze. These results indicate that sulforaphane can effectively prevent the attenuation of LTP and cognitive abilities induced by cholinergic and muscarinic receptor blockade. Further research is warranted to explore the potential therapeutic and prophylactic utility of sulforaphane for improving learning and memory, especially in those suffering from neurodegenerative disorders.
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Affiliation(s)
- Ho-Sub Park
- Department of Gerontology, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin 446-701, Korea
| | - Eun-Sang Hwang
- Department of Gerontology, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin 446-701, Korea
| | - Ga-Young Choi
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, 446-701, Korea
| | - Hyun-Bum Kim
- Department of East-West Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, 446-701, Korea
| | - Kyun-Seob Park
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, 446-701, Korea
| | - Jai-Yoon Sul
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; PENN Program in Single Cell Biology, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Yoonjin Hwang
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, 446-701, Korea
| | - Geun Wook Choi
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, 446-701, Korea
| | - Byung Il Kim
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, 446-701, Korea
| | - Hyunwoo Park
- Health Park Co., Ltd., #2502, Gangnam-dae-Ro 305, Sucho-gu, Seoul 06628, Korea
| | - Sungho Maeng
- Department of Gerontology, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin 446-701, Korea.
| | - Ji-Ho Park
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, 446-701, Korea; Research Institute of Medical Nutrition, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin-si 446-701, Korea.
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10
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He X, Li J, Zhou G, Yang J, McKenzie S, Li Y, Li W, Yu J, Wang Y, Qu J, Wu Z, Hu H, Duan S, Ma H. Gating of hippocampal rhythms and memory by synaptic plasticity in inhibitory interneurons. Neuron 2021; 109:1013-1028.e9. [PMID: 33548174 DOI: 10.1016/j.neuron.2021.01.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 12/17/2020] [Accepted: 01/14/2021] [Indexed: 12/31/2022]
Abstract
Mental experiences can become long-term memories if the hippocampal activity patterns that encode them are broadcast during network oscillations. The activity of inhibitory neurons is essential for generating these neural oscillations, but molecular control of this dynamic process during learning remains unknown. Here, we show that hippocampal oscillatory strength positively correlates with excitatory monosynaptic drive onto inhibitory neurons (E→I) in freely behaving mice. To establish a causal relationship between them, we identified γCaMKII as the long-sought mediator of long-term potentiation for E→I synapses (LTPE→I), which enabled the genetic manipulation of experience-dependent E→I synaptic input/plasticity. Deleting γCaMKII in parvalbumin interneurons selectively eliminated LTPE→I and disrupted experience-driven strengthening in theta and gamma rhythmicity. Behaviorally, this manipulation impaired long-term memory, for which the kinase activity of γCaMKII was required. Taken together, our data suggest that E→I synaptic plasticity, exemplified by LTPE→I, plays a gatekeeping role in tuning experience-dependent brain rhythms and mnemonic function.
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Affiliation(s)
- Xingzhi He
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Jiarui Li
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Guangjun Zhou
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Jing Yang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Sam McKenzie
- Department of Neurosciences, University of New Mexico, Albuquerque, NM 87131, USA
| | - Yanjun Li
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Wenwen Li
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Jun Yu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Yang Wang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Jing Qu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Zhiying Wu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Hailan Hu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China; Research Units for Emotion and Emotion Disorders, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Shumin Duan
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China; Research Units for Emotion and Emotion Disorders, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Huan Ma
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Mental Health Center, Zhejiang University School of Medicine, Hangzhou 310058, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China; Research Units for Emotion and Emotion Disorders, Chinese Academy of Medical Sciences, Beijing 100730, China.
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11
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Cai WT, Han J, Kim WY, Kim JH. Immunohistochemical detection of GluA1 subunit of AMPA receptor in the rat nucleus accumbens following cocaine exposure. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY 2021; 25:79-85. [PMID: 33361540 PMCID: PMC7756536 DOI: 10.4196/kjpp.2021.25.1.79] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 11/15/2022]
Abstract
α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are differentially regulated in the nucleus accumbens (NAcc) of the brain after cocaine exposure. However, these results are supported only by biochemical and electrophysiological methods, but have not been validated with immunohistochemistry. To overcome the restriction of antigen loss on the postsynaptic target molecules that occurs during perfusion-fixation, we adopted an immersion-fixation method that enabled us to immunohistochemically quantify the expression levels of the AMPA receptor GluA1 subunit in the NAcc. Interestingly, compared to saline exposure, cocaine significantly increased the immunofluorescence intensity of GluA1 in two sub-regions, the core and the shell, of the NAcc on withdrawal day 21 following cocaine exposure, which led to locomotor sensitization. Increases in GluA1 intensity were observed in both the extra-post synaptic density (PSD) and PSD areas in the two sub-regions of the NAcc. These results clearly indicate that AMPA receptor plasticity, as exemplified by GluA1, in the NAcc can be visually detected by immunohistochemistry and confocal imaging. These results expand our understanding of the molecular changes occurring in neuronal synapses by adding a new form of analysis to conventional biochemical and electrophysiological methods.
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Affiliation(s)
- Wen Ting Cai
- Department of Physiology, Graduate School of Medical Sciences, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Joonyeup Han
- Department of Physiology, Graduate School of Medical Sciences, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Wha Young Kim
- Department of Physiology, Graduate School of Medical Sciences, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Jeong-Hoon Kim
- Department of Physiology, Graduate School of Medical Sciences, Yonsei University College of Medicine, Seoul 03722, Korea
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12
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Banke TG, Barria A. Transient Enhanced GluA2 Expression in Young Hippocampal Neurons of a Fragile X Mouse Model. Front Synaptic Neurosci 2020; 12:588295. [PMID: 33343326 PMCID: PMC7745073 DOI: 10.3389/fnsyn.2020.588295] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 11/10/2020] [Indexed: 12/29/2022] Open
Abstract
AMPA-type glutamate receptors (AMPARs) are tetrameric ligand-gated channels made up of combinations of GluA1-4 subunits and play important roles in synaptic transmission and plasticity. Here, we have investigated the development of AMPAR-mediated synaptic transmission in the hippocampus of the Fmr1 knock-out (KO) mouse, a widely used model of Fragile X syndrome (FXS). FXS is the leading monogenic cause of intellectual disability and autism spectrum disorders (ASD) and it is considered a neurodevelopmental disorder. For that reason, we investigated synaptic properties and dendritic development in animals from an early stage when synapses are starting to form up to adulthood. We found that hippocampal CA1 pyramidal neurons in the Fmr1-KO mouse exhibit a higher AMPAR-NMDAR ratio early in development but reverses to normal values after P13. This increase was accompanied by a larger presence of the GluA2-subunit in synaptic AMPARs that will lead to altered Ca2+ permeability of AMPARs that could have a profound impact upon neural circuits, learning, and diseases. Following this, we found that young KO animals lack Long-term potentiation (LTP), a well-understood model of synaptic plasticity necessary for proper development of circuits, and exhibit an increased frequency of spontaneous miniature excitatory postsynaptic currents, a measure of synaptic density. Furthermore, post hoc morphological analysis of recorded neurons revealed altered dendritic branching in the KO group. Interestingly, all these anomalies are transitory and revert to normal values in older animals. Our data suggest that loss of FMRP during early development leads to temporary upregulation of the GluA2 subunit and this impacts synaptic plasticity and altering morphological dendritic branching.
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Affiliation(s)
- Tue G Banke
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - Andres Barria
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
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13
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Long-term potentiation of glycinergic synapses by semi-natural stimulation patterns during tonotopic map refinement. Sci Rep 2020; 10:16899. [PMID: 33037263 PMCID: PMC7547119 DOI: 10.1038/s41598-020-73050-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 09/10/2020] [Indexed: 12/22/2022] Open
Abstract
Before the onset of hearing, cochlea-generated patterns of spontaneous spike activity drive the maturation of central auditory circuits. In the glycinergic sound localization pathway from the medial nucleus of the trapezoid body (MNTB) to the lateral superior olive (LSO) this spontaneous activity guides the strengthening and silencing of synapses which underlies tonotopic map refinement. However, the mechanisms by which patterned activity regulates synaptic refinement in the MNTB-LSO pathway are still poorly understood. To address this question, we recorded from LSO neurons in slices from prehearing mice while stimulating MNTB afferents with stimulation patterns that mimicked those present in vivo. We found that these semi-natural stimulation patterns reliably elicited a novel form of long-term potentiation (LTP) of MNTB-LSO synapses. Stimulation patterns that lacked the characteristic high-frequency (200 Hz) component of prehearing spike activity failed to elicit potentiation. LTP was calcium dependent, required the activation of both g-protein coupled GABAB and metabotropic glutamate receptors and involved an increase in postsynaptic glycine receptor-mediated currents. Our results provide a possible mechanism linking spontaneous spike bursts to tonotopic map refinement and further highlight the importance of the co-release of GABA and glutamate from immature glycinergic MNTB terminals.
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14
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Singh B, Covelo A, Martell-Martínez H, Nanclares C, Sherman MA, Okematti E, Meints J, Teravskis PJ, Gallardo C, Savonenko AV, Benneyworth MA, Lesné SE, Liao D, Araque A, Lee MK. Tau is required for progressive synaptic and memory deficits in a transgenic mouse model of α-synucleinopathy. Acta Neuropathol 2019; 138:551-574. [PMID: 31168644 PMCID: PMC6778173 DOI: 10.1007/s00401-019-02032-w] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/27/2019] [Accepted: 05/27/2019] [Indexed: 01/01/2023]
Abstract
Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB) are clinically and neuropathologically highly related α-synucleinopathies that collectively constitute the second leading cause of neurodegenerative dementias. Genetic and neuropathological studies directly implicate α-synuclein (αS) abnormalities in PDD and DLB pathogenesis. However, it is currently unknown how αS abnormalities contribute to memory loss, particularly since forebrain neuronal loss in PDD and DLB is less severe than in Alzheimer's disease. Previously, we found that familial Parkinson's disease-linked human mutant A53T αS causes aberrant localization of the microtubule-associated protein tau to postsynaptic spines in neurons, leading to postsynaptic deficits. Thus, we directly tested if the synaptic and memory deficits in a mouse model of α-synucleinopathy (TgA53T) are mediated by tau. TgA53T mice exhibit progressive memory deficits associated with postsynaptic deficits in the absence of obvious neuropathological and neurodegenerative changes in the hippocampus. Significantly, removal of endogenous mouse tau expression in TgA53T mice (TgA53T/mTau-/-), achieved by mating TgA53T mice to mouse tau-knockout mice, completely ameliorates cognitive dysfunction and concurrent synaptic deficits without affecting αS expression or accumulation of selected toxic αS oligomers. Among the known tau-dependent effects, memory deficits in TgA53T mice were associated with hippocampal circuit remodeling linked to chronic network hyperexcitability. This remodeling was absent in TgA53T/mTau-/- mice, indicating that postsynaptic deficits, aberrant network hyperactivity, and memory deficits are mechanistically linked. Our results directly implicate tau as a mediator of specific human mutant A53T αS-mediated abnormalities related to deficits in hippocampal neurotransmission and suggest a mechanism for memory impairment that occurs as a consequence of synaptic dysfunction rather than synaptic or neuronal loss. We hypothesize that these initial synaptic deficits contribute to network hyperexcitability which, in turn, exacerbate cognitive dysfunction. Our results indicate that these synaptic changes present potential therapeutic targets for amelioration of memory deficits in α-synucleinopathies.
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Affiliation(s)
- Balvindar Singh
- Medical Scientist Training Program, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
- Graduate Program in Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Ana Covelo
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Héctor Martell-Martínez
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Carmen Nanclares
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Mathew A Sherman
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Emmanuel Okematti
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Joyce Meints
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Peter J Teravskis
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Christopher Gallardo
- Graduate Program in Pharmacology, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Alena V Savonenko
- Department of Pathology, Johns Hopkins University School of Medicine, 733 N Broadway, Baltimore, MD, 21205, USA
| | - Michael A Benneyworth
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
- Institute for Translational Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
- Mouse Behavior Core, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Sylvain E Lesné
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
- Institute for Translational Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
- N. Budd Grossman Center for Memory Research and Care, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Dezhi Liao
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
- Institute for Translational Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
- Institute for Translational Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA
| | - Michael K Lee
- Department of Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA.
- Institute for Translational Neuroscience, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA.
- Geriatric Research Education and Clinical Center, Minneapolis Veterans Affairs Health Care System, University of Minnesota Medical School, 420 Delaware Street SE, Minneapolis, MN, 55455, USA.
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15
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Zhang T, Shi Z, Wang Y, Wang L, Zhang B, Chen G, Wan Q, Chen L. Akt3 deletion in mice impairs spatial cognition and hippocampal CA1 long long-term potentiation through downregulation of mTOR. Acta Physiol (Oxf) 2019; 225:e13167. [PMID: 30053339 DOI: 10.1111/apha.13167] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 07/20/2018] [Accepted: 07/24/2018] [Indexed: 11/30/2022]
Abstract
AIM Loss-of-function mutation of Akt3 in humans has been associated with microcephaly and cognitive defects. Two Akt isoforms, Akt1 and Akt3, are highly expressed in hippocampal pyramidal cells. We explored the roles of Akt1 and Akt3, respectively, in spatial cognition and underlying mechanisms. METHODS We used Akt1 knockout (Akt1-KO) and Akt3 knockout (Akt3-KO) mice to examine the influence of Akt1 and Akt3 deficiency on spatial memory, as well as induction and maintenance of hippocampal CA1 NMDA receptor-dependent and protein synthesis-dependent long-term potentiation (LTP). RESULTS Long-term spatial memory was impaired in Akt3-KO mice, but not in Akt1-KO mice, as assessed by the Morris water maze task. Akt3-KO and Akt1-KO mice displayed reductions in brain size without concurrent changes in the number of pyramidal cells or basal properties of synaptic transmission. One-train high-frequency stimulation (HFS × 1) induced NMDA receptor-dependent LTP in Akt3-KO mice and Akt1-KO mice. Four-train HFS (HFS × 4) induced rapamycin-sensitive long-LTP in Akt1-KO mice, but not Akt3-KO mice. Basal level of mTOR phosphorylation was reduced in Akt3-KO mice rather than Akt1-KO mice. HFS × 4 induced an elevation of mTOR and p70S6K phosphorylation in Akt1-KO mice, which led to enhanced 4EBP2 and eIF4E phosphorylation along with an increase in AMPA receptor protein. However, the same protocol of HFS × 4 failed to trigger the mTOR-p70S6K signalling cascade or increase 4EBP2 and eIF4E phosphorylation in Akt3-KO mice. CONCLUSION The Akt3 deficiency via inactivation of mTOR suppresses HFS × 4-induced mTOR-p70S6K signalling to reduce phosphorylation of 4EBP and eIF4E, which impairs protein synthesis-dependent long-LTP and long-term spatial cognitive function.
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Affiliation(s)
- Tingting Zhang
- State Key Lab of Reproductive Medicine; Nanjing Medical University; Nanjing China
- Department of Physiology; Nanjing Medical University; Nanjing China
| | - Zhaochun Shi
- Department of Neurology; First Affiliated Hospital of Nanjing Medical University; Nanjing China
| | - Ya Wang
- Department of Physiology; Nanjing Medical University; Nanjing China
| | - Ling Wang
- Department of Physiology; Nanjing Medical University; Nanjing China
| | - Baofeng Zhang
- Department of Physiology; Nanjing Medical University; Nanjing China
| | - Guiquan Chen
- State Key Laboratory of Pharmaceutical Biotechnology; MOE Key Laboratory of Model Animal for Disease Study; Model Animal Research Center; Nanjing University; Nanjing China
| | - Qi Wan
- Department of Neurology; First Affiliated Hospital of Nanjing Medical University; Nanjing China
| | - Ling Chen
- State Key Lab of Reproductive Medicine; Nanjing Medical University; Nanjing China
- Department of Physiology; Nanjing Medical University; Nanjing China
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16
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Bennabi D, Haffen E, Van Waes V. Vortioxetine for Cognitive Enhancement in Major Depression: From Animal Models to Clinical Research. Front Psychiatry 2019; 10:771. [PMID: 31780961 PMCID: PMC6851880 DOI: 10.3389/fpsyt.2019.00771] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 09/25/2019] [Indexed: 12/21/2022] Open
Abstract
Objectives: Vortioxetine has already shown its efficacy in the acute and long-term treatment of major depressive disorder (MDD) and its potential interest in the prevention of relapse. The aim of this study was to review the current status of knowledge regarding its cognitive effects. Methods: We conducted a review of key data obtained from preclinical behavioral models and clinical trials in MDD focusing on vortioxetine-induced cognitive changes. Results: In animals, acute and chronic administration of vortioxetine improves performance on objective measures that cover a broad range of cognitive domains. In human, vortioxetine appears to be a useful treatment option in MDD patients with cognitive dysfunction. Conclusion: Vortioxetine constitutes a promising treatment for treatment of cognitive impairment in MDD, but its place in the therapeutic armamentarium still needs to be determined.
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Affiliation(s)
- Djamila Bennabi
- Department of Clinical Psychiatry, INSERM, CHU de Besançon, Neurosciences, University Bourgogne Franche-Comté, FondaMental Foundation, Creteil, France
| | - Emmanuel Haffen
- Department of Clinical Psychiatry, INSERM, CHU de Besançon, Neurosciences, University Bourgogne Franche-Comté, FondaMental Foundation, Creteil, France
| | - Vincent Van Waes
- Laboratory of Integrative and Clinical Neuroscience, University of Bourgogne Franche-Comté, Besançon, France
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17
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Dong J, Zhou Q, Wei Z, Yan S, Sun F, Cai X. Protein kinase A mediates scopolamine-induced mTOR activation and an antidepressant response. J Affect Disord 2018; 227:633-642. [PMID: 29174736 DOI: 10.1016/j.jad.2017.11.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 11/11/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Clinical reports have shown that scopolamine produces a rapid (3-4 d) and potent anti-depressive response without severe adverse effects. Animal experiments have proven that scopolamine induces mTOR pathway activation in an AMPAR dependent manner. The present study aimed to determine the role of PKA in scopolamine-induced potentiation of AMPAR, as well as in mTOR pathway activation and rapid antidepressant effects. METHODS We utilized electrophysiological recording, Western blotting, and behavior tests to examine the effects of scopolamine, the selective M2 cholinergic receptor antagonist methoctramine, and H89, a PKA specific inhibitor on AMPAR potentiation, mTOR pathway activation, and behavioral responses in a rat depression model of learned helplessness. RESULTS Scopolamine (1μM) rapidly increased AMPAR-fEPSP amplitudes and membrane GluA1 expression in CA1 region of hippocampal slices, both of which were abolished by H89. Moreover, scopolamine promoted AMPAR phosphorylation on GluA1 ser845, a PKA site involved in GluA1 membrane insertion. H89 disrupted both GluA1 ser845 phosphorylation and mTOR activation, as well as the antidepressant effects of scopolamine as determined via forced swim test. Additionally, methoctramine mimicked the effects of scopolamine on phosphorylation and counter-depressive action in a PKA-dependent manner. LIMITATIONS Only one test was used to evaluate depressive behavior, and gene knock-out rats were not yet utilized to refine our hypotheses. CONCLUSION Our findings revealed that PKA pathway is necessary for scopolamine-induced synaptic plasticity and mTOR pathway activation, and indicated that a potential M2-PKA mechanism underlies scopolamine's antidepressant effects. Such findings suggest that GluA1 ser845 phosphorylation may be a trigger event for scopolamine's actions, and that PKA may represent a novel target for the treatment of depressive symptoms.
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Affiliation(s)
- Jianyang Dong
- Institute of Neurosciences, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qinji Zhou
- Institute of Neurosciences, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zhisheng Wei
- Department of Neurology, School of Clinical Medicine, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China
| | - Shi Yan
- Institute of Neurosciences, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Fangfang Sun
- Institute of Neurosciences, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xiang Cai
- Institute of Neurosciences, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China; Department of Physiology, Southern Illinois University, Carbondale, IL, USA.
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18
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Matur Z, Öge AE. Sensorimotor Integration During Motor Learning: Transcranial Magnetic Stimulation Studies. ACTA ACUST UNITED AC 2017; 54:358-363. [PMID: 29321712 DOI: 10.5152/npa.2016.18056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of sensory signals coming from skin and muscle afferents on the sensorimotor cortical networks is entitled as sensory-motor integration (SMI). SMI can be studied electrophysiologically by the motor cortex excitability changes in response to peripheral sensory stimulation. These changes include the periods of short afferent inhibition (SAI), afferent facilitation (AF), and late afferent inhibition (LAI). During the early period of motor skill acquisition, motor cortex excitability increases and changes occur in the area covered by the relevant zone of the motor cortex. In the late period, these give place to the morphological changes, such as synaptogenesis. SAI decreases during learning the motor skills, while LAI increases during motor activity. In this review, the role of SMI in the process of motor learning and transcranial magnetic stimulation techniques performed for studying SMI is summarized.
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Affiliation(s)
- Zeliha Matur
- Department of Neurology, İstanbul Bilim University School of Medicine, İstanbul, Turkey
| | - A Emre Öge
- Department of Neurology, İstanbul University İstanbul School of Medicine, İstanbul, Turkey
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19
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The AMPA Receptor Subunit GluA1 is Required for CA1 Hippocampal Long-Term Potentiation but is not Essential for Synaptic Transmission. Neurochem Res 2017; 44:549-561. [PMID: 29098531 DOI: 10.1007/s11064-017-2425-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 09/13/2017] [Accepted: 10/21/2017] [Indexed: 10/18/2022]
Abstract
AMPA receptors mediate the majority of excitatory glutamatergic transmission in the mammalian brain and are heterotetramers composed of GluA1-4 subunits. Despite genetic studies, the roles of the subunits in synaptic transmission and plasticity remain controversial. To address this issue, we investigated the effects of cell-specific removal of GluA1 in hippocampal CA1 pyramidal neurons using virally-expressed GluA1 shRNA in organotypic slice culture. We show that this shRNA approach produces a rapid, efficient and selective loss of GluA1, and removed > 80% of surface GluA1 from synapses. This loss of GluA1 caused a modest reduction (up to 57%) in synaptic transmission and when applied in neurons from GluA3 knock-out mice, a similar small reduction in transmission occurred. Further, we found that loss of GluA1 caused a redistribution of GluA2 to synapses that may compensate functionally for the absence of GluA1. We found that LTP was absent in neurons lacking GluA1, induced either by pairing or by a theta-burst pairing protocol previously shown to induce LTP in GluA1 knock-out mice. Our findings demonstrate a critical role of GluA1 in CA1 LTP, but no absolute requirement for GluA1 in maintaining synaptic transmission. Further, our results indicate that GluA2 homomers can mediate synaptic transmission and can compensate for loss of GluA1.
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20
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Lee SH, Jin C, Cai E, Ge P, Ishitsuka Y, Teng KW, de Thomaz AA, Nall D, Baday M, Jeyifous O, Demonte D, Dundas CM, Park S, Delgado JY, Green WN, Selvin PR. Super-resolution imaging of synaptic and Extra-synaptic AMPA receptors with different-sized fluorescent probes. eLife 2017; 6:27744. [PMID: 28749340 PMCID: PMC5779237 DOI: 10.7554/elife.27744] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/26/2017] [Indexed: 12/13/2022] Open
Abstract
Previous studies tracking AMPA receptor (AMPAR) diffusion at synapses observed a large mobile extrasynaptic AMPAR pool. Using super-resolution microscopy, we examined how fluorophore size and photostability affected AMPAR trafficking outside of, and within, post-synaptic densities (PSDs) from rats. Organic fluorescent dyes (≈4 nm), quantum dots, either small (≈10 nm diameter; sQDs) or big (>20 nm; bQDs), were coupled to AMPARs via different-sized linkers. We find that >90% of AMPARs labeled with fluorescent dyes or sQDs were diffusing in confined nanodomains in PSDs, which were stable for 15 min or longer. Less than 10% of sQD-AMPARs were extrasynaptic and highly mobile. In contrast, 5-10% of bQD-AMPARs were in PSDs and 90-95% were extrasynaptic as previously observed. Contrary to the hypothesis that AMPAR entry is limited by the occupancy of open PSD 'slots', our findings suggest that AMPARs rapidly enter stable 'nanodomains' in PSDs with lifetime >15 min, and do not accumulate in extrasynaptic membranes.
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Affiliation(s)
- Sang Hak Lee
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - Chaoyi Jin
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - En Cai
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - Pinghua Ge
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - Yuji Ishitsuka
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - Kai Wen Teng
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - Andre A de Thomaz
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - Duncan Nall
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - Murat Baday
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
| | - Okunola Jeyifous
- Department of Neurobiology, University of Chicago and the Marine Biological Laboratory, Chicago, United States
| | - Daniel Demonte
- Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, United States
| | - Christopher M Dundas
- Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, United States
| | - Sheldon Park
- Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, United States
| | - Jary Y Delgado
- Department of Neurobiology, University of Chicago and the Marine Biological Laboratory, Chicago, United States
| | - William N Green
- Department of Neurobiology, University of Chicago and the Marine Biological Laboratory, Chicago, United States
| | - Paul R Selvin
- Department of Physics, Center for Biophysics, and Quantitative Biology, and Center for the Physics of Living Cells, University of Illinois, Urbana-Champaign, Champaign, United States
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Watson JF, Ho H, Greger IH. Synaptic transmission and plasticity require AMPA receptor anchoring via its N-terminal domain. eLife 2017; 6. [PMID: 28290985 PMCID: PMC5370185 DOI: 10.7554/elife.23024] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 03/04/2017] [Indexed: 12/02/2022] Open
Abstract
AMPA-type glutamate receptors (AMPARs) mediate fast excitatory neurotransmission and are selectively recruited during activity-dependent plasticity to increase synaptic strength. A prerequisite for faithful signal transmission is the positioning and clustering of AMPARs at postsynaptic sites. The mechanisms underlying this positioning have largely been ascribed to the receptor cytoplasmic C-termini and to AMPAR-associated auxiliary subunits, both interacting with the postsynaptic scaffold. Here, using mouse organotypic hippocampal slices, we show that the extracellular AMPAR N-terminal domain (NTD), which projects midway into the synaptic cleft, plays a fundamental role in this process. This highly sequence-diverse domain mediates synaptic anchoring in a subunit-selective manner. Receptors lacking the NTD exhibit increased mobility in synapses, depress synaptic transmission and are unable to sustain long-term potentiation (LTP). Thus, synaptic transmission and the expression of LTP are dependent upon an AMPAR anchoring mechanism that is driven by the NTD. DOI:http://dx.doi.org/10.7554/eLife.23024.001 Neurons send signals via electrical impulses that are transmitted between cells by small molecules known as neurotransmitters. The information is passed from neuron to neuron at specialized points of contact termed synapses. On release of neurotransmitters from the first neuron, the molecules attach to ‘docking stations’ called receptors on the next neuron, referred to as the postsynaptic cell. One of these receptors, the AMPA receptor, transmits signals by binding to a neurotransmitter called glutamate. Previous research has shown that in order to bind glutamate effectively, these receptors need to be trapped and anchored at the correct location at the synapse. This trapping mechanism controls the number of receptors present, which strengthens the synapse, and ultimately mediates learning and memory. However, it is still not clear how AMPA receptor trapping is achieved. To investigate this question, Watson et al. examined how AMPA receptors (and mutant forms of the receptor) affect the communication between neurons using brain slices from mice. The experiments show that an external segment of the AMPA receptor called the N-terminal domain (or NTD for short) is a key element for receptor anchoring at the postsynapse. The AMPA receptor is made out of four different subunits; when the NTD portion was removed from one specific subunit, fewer receptors were anchored correctly at the postsynapse. When the NTD was removed from another subunit, it completely prevented the synapse from learning. Therefore, the NTD brings about subunit-selective anchoring of the AMPA receptor, which affects the ability of the synapse to transmit signals. Important next steps would be to identify the proteins that interact with the NTD and how this specific anchoring affects the strength of the synapse. Another key step will be to understand what mechanisms control the number of AMPA receptors at synapses, to ultimately enable learning. DOI:http://dx.doi.org/10.7554/eLife.23024.002
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Affiliation(s)
- Jake F Watson
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Hinze Ho
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Ingo H Greger
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
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22
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Spampinato D, Celnik P. Temporal dynamics of cerebellar and motor cortex physiological processes during motor skill learning. Sci Rep 2017; 7:40715. [PMID: 28091578 PMCID: PMC5238434 DOI: 10.1038/srep40715] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 12/08/2016] [Indexed: 11/30/2022] Open
Abstract
Learning motor tasks involves distinct physiological processes in the cerebellum (CB) and primary motor cortex (M1). Previous studies have shown that motor learning results in at least two important neurophysiological changes: modulation of cerebellar output mediated in-part by long-term depression of parallel fiber-Purkinje cell synapse and induction of long-term plasticity (LTP) in M1, leading to transient occlusion of additional LTP-like plasticity. However, little is known about the temporal dynamics of these two physiological mechanisms during motor skill learning. Here we use non-invasive brain stimulation to explore CB and M1 mechanisms during early and late motor skill learning in humans. We predicted that early skill acquisition would be proportional to cerebellar excitability (CBI) changes, whereas later stages of learning will result in M1 LTP-like plasticity modifications. We found that early, and not late into skill training, CBI changed. Whereas, occlusion of LTP-like plasticity over M1 occurred only during late, but not early training. These findings indicate a distinct temporal dissociation in the physiological role of the CB and M1 when learning a novel skill. Understanding the role and temporal dynamics of different brain regions during motor learning is critical to device optimal interventions to augment learning.
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Affiliation(s)
- D Spampinato
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, 720 Rutland Avenue Baltimore, MD 21205, USA.,Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, 600 North Wolfe Street Baltimore, MD 21287, USA
| | - P Celnik
- Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, 600 North Wolfe Street Baltimore, MD 21287, USA.,Department of Neuroscience, Johns Hopkins School of Medicine, 725 North Wolfe Street Baltimore, MD 21205, USA.,Department of Neurology, Johns Hopkins School of Medicine, 600 North Wolfe Street Baltimore, MD 21287, USA
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23
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David DJ, Tritschler L, Guilloux JP, Gardier AM, Sanchez C, Gaillard R. [Pharmacological properties of vortioxetine and its pre-clinical consequences]. Encephale 2016; 42:1S12-23. [PMID: 26879252 DOI: 10.1016/s0013-7006(16)30015-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Selective Serotonin Reuptake Inhibitors (SSRIs) are extensively used for the treatment of major depressive disorder (MDD). SSRIs are defined as indirect receptor agonists since the activation of postsynaptic receptors is a consequence of an increase in extracellular concentrations of serotonin (5-HT) mediated by the blockade of serotonin transporter. The activation of some serotoninergic receptors (5-HT1A, post-synaptic, 5-HT1B post-synaptic, 5-HT2B, and 5-HT4), but not all (5-HT1A, pre-synaptic, 5-HT1B pre-synaptic, 5-HT2A, 5-HT2C, 5-HT3, and probably 5-HT6), induces anxiolytic/antidepressive - like effects. Targetting specifically some of them could potentially improve the onset of action and/or efficacy and/or prevent MD relapse. Vortioxetine (Brintellix, 1- [2-(2,4-dimethylphenyl-sulfanyl)-phenyl]-piperazine) is a novel multi-target antidepressant drug approved by the Food and Drug Administration (FDA) and by European Medicines Agency. Its properties are markedly different from the extensively prescribed SSRIs. Compared to the SSRIs, vortioxetine is defined as a multimodal antidepressant drug since it is not only a serotonin reuptake inhibitor, but also a 5-HT1D, 5-HT3, 5-HT7 receptor antagonist, 5-HT1B receptor partial agonist and 5-HT1A receptor agonist. This specific pharmacological profile enables vortioxetine to affect not only the serotoninergic and noradrenergic systems, but also the histaminergic, cholinergic, gamma-butyric acid (GABA) ergic and glutamatergic ones. Thus, vortioxetine not only induces antidepressant-like or anxiolytic-like activity but also improves cognitive parameters in several animal models. Indeed, vortioxetine was shown to improve working memory, episodic memory, cognitive flexibility and spatial memory in young adult rodents and also in old animal models. These specific effects of the vortioxetine are of interest considering that cognitive dysfunction is a common comorbidity to MDD. Altogether, even though this molecule still needs to be investigated further, especially in the insufficient-response to antidepressant drugs, vortioxetine is already an innovative therapeutic option for the treatment of major depression.
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Affiliation(s)
- D J David
- Inserm UMR-S 1178 Santé Mentale et Santé Publique, Université Paris-Sud, Fac Pharmacie, Université Paris Saclay, Châtenay-Malabry, France; DJD et LT ont contribué de façon équivalente à l'élaboration du manuscrit
| | - L Tritschler
- Inserm UMR-S 1178 Santé Mentale et Santé Publique, Université Paris-Sud, Fac Pharmacie, Université Paris Saclay, Châtenay-Malabry, France; DJD et LT ont contribué de façon équivalente à l'élaboration du manuscrit
| | - J-P Guilloux
- Inserm UMR-S 1178 Santé Mentale et Santé Publique, Université Paris-Sud, Fac Pharmacie, Université Paris Saclay, Châtenay-Malabry, France
| | - A M Gardier
- Inserm UMR-S 1178 Santé Mentale et Santé Publique, Université Paris-Sud, Fac Pharmacie, Université Paris Saclay, Châtenay-Malabry, France
| | - C Sanchez
- Lundbeck Research USA, Inc., 215 College Road, 07652 Paramus, NJ, United States
| | - R Gaillard
- Service Hospitalo-Universitaire - Addictologie, Centre Hospitalier Sainte Anne, 1, rue Cabanis, 75674 Paris cedex 14, France.
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24
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Abstract
For more than 20 years, we have known that Ca(2+)/calmodulin-dependent protein kinase (CaMKII) activation is both necessary and sufficient for the induction of long-term potentiation (LTP). During this time, tremendous effort has been spent in attempting to understand how CaMKII activation gives rise to this phenomenon. Despite such efforts, there is much to be learned about the molecular mechanisms involved in LTP induction downstream of CaMKII activation. In this review, we highlight recent developments that have shaped our current thinking about the molecular mechanisms underlying LTP and discuss important questions that remain in the field.
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Affiliation(s)
| | - Roger A Nicoll
- Department of Cellular and Molecular Pharmacology and.,Department of Physiology, University of California, San Francisco, California 94143; ,
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25
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Mansur F, Ivshina M, Gu W, Schaevitz L, Stackpole E, Gujja S, Edwards YJK, Richter JD. Gld2-catalyzed 3' monoadenylation of miRNAs in the hippocampus has no detectable effect on their stability or on animal behavior. RNA (NEW YORK, N.Y.) 2016; 22:1492-9. [PMID: 27495319 PMCID: PMC5029448 DOI: 10.1261/rna.056937.116] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/30/2016] [Indexed: 05/20/2023]
Abstract
Gld2, a noncanonical cytoplasmic poly(A) polymerase, interacts with the RNA binding protein CPEB1 to mediate polyadenylation-induced translation in dendrites of cultured hippocampal neurons. Depletion of Gld2 from the hippocampus leads to a deficit in long-term potentiation evoked by theta burst stimulation. At least in mouse liver and human primary fibroblasts, Gld2 also 3' monoadenylates and thereby stabilizes specific miRNAs, which enhance mRNA translational silencing and eventual destruction. These results suggest that Gld2 would be likely to monoadenylate and stabilize miRNAs in the hippocampus, which would produce measurable changes in animal behavior. We now report that using Gld2 knockout mice, there are detectable alterations in specific miRNA monoadenylation in the hippocampus when compared to wild type, but that these modifications produce no detectable effect on miRNA stability. Moreover, we surprisingly find no overt change in animal behavior when comparing Gld2 knockout to wild-type mice. These data indicate that miRNA monoadenylation-mediated stability is cell type-specific and that monoadenylation has no measurable effect on higher cognitive function.
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Affiliation(s)
- Fernanda Mansur
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Maria Ivshina
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Weifeng Gu
- Department of Cell Biology and Neuroscience, University of California at Riverside, Riverside, California 92521, USA
| | - Laura Schaevitz
- Animal Research and Development, Mousera, San Mateo, California 94402, USA
| | - Emily Stackpole
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Sharvari Gujja
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Yvonne J K Edwards
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Joel D Richter
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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26
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Abstract
Craniofacial nociceptive processing in patients ( n = 25) suffering from unilateral cluster headache was assessed by laser-evoked cortical potentials (LEPs). Latencies and amplitudes of late (N2, P2) and middle-latency (N1) LEPs were measured in chronic (CCH, n = 9) and episodic cluster headache (ECH, n = 17). In CCH patients on headache side N1c occurred later and P2 amplitude was smaller than on the healthy control side. In active periods of ECH patients P2 latency was shorter on the headache side. In remission periods of ECH patients the N2P2 ratio was lower on the headache side. In 19 out of 26 examinations in 25 headache patients LEP deviated from normative data in healthy controls ( n = 10) without any specific pattern of altered parameters. LEPs document pathological changes in craniofacial nociception in cluster headache. However, there seems to be no pathognomonic deviation pattern that enables reliable diagnosis of cluster headache and application of LEPs in further studies of pathophysiological mechanisms.
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Affiliation(s)
- J Ellrich
- Department of Neurosurgery, Experimental Neurosurgery Section, RWTH Aachen University, Aachen, Germany.
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27
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Ge YX, Tian XZ, Lin YY, Liu XY. Chronic treatment with levetiracetam reverses deficits in hippocampal LTP in vivo in experimental temporal lobe epilepsy rats. Neurosci Lett 2016; 628:194-200. [PMID: 27345386 DOI: 10.1016/j.neulet.2016.06.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 06/10/2016] [Accepted: 06/21/2016] [Indexed: 12/21/2022]
Abstract
Temporal lobe epilepsy (TLE), the common form of epilepsy in adults, often displays complex partial seizures and cognitive deficits. The underlying mechanisms of such deficits are not yet well understood. Many contributing factors, such as initial epileptogenic lesion, seizure type, age of onset, and treatment side effects have been proposed. Levetiracetam (LEV) is a novel anti-epileptic drug (AED) used to treat partial seizures and idiopathic generalized epilepsy. It has been suggested that LEV exerts antiepileptic properties by modulation of synaptic release of neurotransmitters. However, its neuroprotective effects on learning and memory are not yet well demonstrated. Here we showed the impairment of spatial memory in the pilocarpine-induced experimental TLE rats, which can be improved by LEV. Furthermore, we found chronic LEV treatment partially reversed the SE-induced synaptic dysfunction in hippocampal LTP induction in vivo. In addition, LEV treatment can alleviate the SE-induced abnormal GluR1 phosphorylation at Ser(831) site, which may contribute to the rescue of synaptic transmission. These results indicate the neuroprotective role for LEV while it exhibits an antiseizure effect on experimental epileptic models.
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Affiliation(s)
- Yu-Xing Ge
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Xiang-Zhu Tian
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Ying-Ying Lin
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Xue-Yuan Liu
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China.
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28
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Ryu HH, Lee YS. Cell type-specific roles of RAS-MAPK signaling in learning and memory: Implications in neurodevelopmental disorders. Neurobiol Learn Mem 2016; 135:13-21. [PMID: 27296701 DOI: 10.1016/j.nlm.2016.06.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/28/2016] [Accepted: 06/09/2016] [Indexed: 01/17/2023]
Abstract
The RAS-mitogen-activated protein kinase (MAPK) signaling pathway plays critical roles in brain function, including learning and memory. Mutations of molecules in the RAS-MAPK pathway are associated with a group of disorders called RASopathies, which include Noonan syndrome, neurofibromatosis type 1, Costello syndrome, Noonan syndrome with multiple lentigines, Legius syndrome, and cardio-facio-cutaneous syndrome. RASopathies share certain clinical symptoms, including craniofacial abnormalities, heart defects, delayed growth, and cognitive deficits such as learning disabilities, while each individual syndrome also displays unique phenotypes. Recent studies using mouse models of RASopathies showed that each disorder may have a distinct molecular and cellular etiology depending on the cellular specificity of the mutated molecules. Here, we review the cell-type specific roles of the regulators of the RAS-MAPK pathway in cognitive function (learning and memory) and their contribution to the development of RASopathies. We also discussed recent technical advances in analyzing cell type-specific transcriptomes and proteomes in the nervous system. Understanding specific mechanisms for these similar but distinct disorders would facilitate the development of mechanism-based individualized treatment for RASopathies.
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Affiliation(s)
- Hyun-Hee Ryu
- Department of Life Science, College of Natural Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, South Korea; Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Yong-Seok Lee
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
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29
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Posttranslational Modifications Regulate the Postsynaptic Localization of PSD-95. Mol Neurobiol 2016; 54:1759-1776. [PMID: 26884267 DOI: 10.1007/s12035-016-9745-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/22/2016] [Indexed: 01/08/2023]
Abstract
The postsynaptic density (PSD) consists of a lattice-like array of interacting proteins that organizes and stabilizes synaptic receptors, ion channels, structural proteins, and signaling molecules required for normal synaptic transmission and synaptic function. The scaffolding and hub protein postsynaptic density protein-95 (PSD-95) is a major element of central chemical synapses and interacts with glutamate receptors, cell adhesion molecules, and cytoskeletal elements. In fact, PSD-95 can regulate basal synaptic stability as well as the activity-dependent structural plasticity of the PSD and, therefore, of the excitatory chemical synapse. Several studies have shown that PSD-95 is highly enriched at excitatory synapses and have identified multiple protein structural domains and protein-protein interactions that mediate PSD-95 function and trafficking to the postsynaptic region. PSD-95 is also a target of several signaling pathways that induce posttranslational modifications, including palmitoylation, phosphorylation, ubiquitination, nitrosylation, and neddylation; these modifications determine the synaptic stability and function of PSD-95 and thus regulate the fates of individual dendritic spines in the nervous system. In the present work, we review the posttranslational modifications that regulate the synaptic localization of PSD-95 and describe their functional consequences. We also explore the signaling pathways that induce such changes.
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30
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Zhou Y, Tencerová B, Hartveit E, Veruki ML. Functional NMDA receptors are expressed by both AII and A17 amacrine cells in the rod pathway of the mammalian retina. J Neurophysiol 2016; 115:389-403. [PMID: 26561610 PMCID: PMC4760463 DOI: 10.1152/jn.00947.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 11/08/2015] [Indexed: 11/22/2022] Open
Abstract
At many glutamatergic synapses, non-N-methyl-d-aspartate (NMDA) and NMDA receptors are coexpressed postsynaptically. In the mammalian retina, glutamatergic rod bipolar cells are presynaptic to two rod amacrine cells (AII and A17) that constitute dyad postsynaptic partners opposite each presynaptic active zone. Whereas there is strong evidence for expression of non-NMDA receptors by both AII and A17 amacrines, the expression of NMDA receptors by the pre- and postsynaptic neurons in this microcircuit has not been resolved. In this study, using patch-clamp recording from visually identified cells in rat retinal slices, we investigated the expression and functional properties of NMDA receptors in these cells with a combination of pharmacological and biophysical methods. Pressure application of NMDA did not evoke a response in rod bipolar cells, but for both AII and A17 amacrines, NMDA evoked responses that were blocked by a competitive antagonist (CPP) applied extracellularly and an open channel blocker (MK-801) applied intracellularly. NMDA-evoked responses also displayed strong Mg(2+)-dependent voltage block and were independent of gap junction coupling. With low-frequency application (60-s intervals), NMDA-evoked responses remained stable for up to 50 min, but with higher-frequency stimulation (10- to 20-s intervals), NMDA responses were strongly and reversibly suppressed. We observed strong potentiation when NMDA was applied in nominally Ca(2+)-free extracellular solution, potentially reflecting Ca(2+)-dependent NMDA receptor inactivation. These results indicate that expression of functional (i.e., conductance-increasing) NMDA receptors is common to both AII and A17 amacrine cells and suggest that these receptors could play an important role for synaptic signaling, integration, or plasticity in the rod pathway.
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Affiliation(s)
- Yifan Zhou
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Espen Hartveit
- Department of Biomedicine, University of Bergen, Bergen, Norway
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31
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Bell RL, Hauser SR, McClintick J, Rahman S, Edenberg HJ, Szumlinski KK, McBride WJ. Ethanol-Associated Changes in Glutamate Reward Neurocircuitry: A Minireview of Clinical and Preclinical Genetic Findings. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 137:41-85. [PMID: 26809998 DOI: 10.1016/bs.pmbts.2015.10.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Herein, we have reviewed the role of glutamate, the major excitatory neurotransmitter in the brain, in a number of neurochemical, -physiological, and -behavioral processes mediating the development of alcohol dependence. The findings discussed include results from both preclinical as well as neuroimaging and postmortem clinical studies. Expression levels for a number of glutamate-associated genes and/or proteins are modulated by alcohol abuse and dependence. These changes in expression include metabotropic receptors and ionotropic receptor subunits as well as different glutamate transporters. Moreover, these changes in gene expression parallel the pharmacologic manipulation of these same receptors and transporters. Some of these gene expression changes may have predated alcohol abuse and dependence because a number of glutamate-associated polymorphisms are related to a genetic predisposition to develop alcohol dependence. Other glutamate-associated polymorphisms are linked to age at the onset of alcohol-dependence and initial level of response/sensitivity to alcohol. Finally, findings of innate and/or ethanol-induced glutamate-associated gene expression differences/changes observed in a genetic animal model of alcoholism, the P rat, are summarized. Overall, the existing literature indicates that changes in glutamate receptors, transporters, enzymes, and scaffolding proteins are crucial for the development of alcohol dependence and there is a substantial genetic component to these effects. This indicates that continued research into the genetic underpinnings of these glutamate-associated effects will provide important novel molecular targets for treating alcohol abuse and dependence.
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Affiliation(s)
- Richard L Bell
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA.
| | - Sheketha R Hauser
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Jeanette McClintick
- Departments of Biochemistry and Molecular Biology and Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana , USA
| | - Shafiqur Rahman
- Department of Pharmaceutical Sciences, South Dakota State University, Brookings, South Dakota, USA
| | - Howard J Edenberg
- Departments of Biochemistry and Molecular Biology and Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana , USA
| | - Karen K Szumlinski
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, California, USA
| | - William J McBride
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Structural Components of Synaptic Plasticity and Memory Consolidation. Cold Spring Harb Perspect Biol 2015; 7:a021758. [PMID: 26134321 DOI: 10.1101/cshperspect.a021758] [Citation(s) in RCA: 243] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Consolidation of implicit memory in the invertebrate Aplysia and explicit memory in the mammalian hippocampus are associated with remodeling and growth of preexisting synapses and the formation of new synapses. Here, we compare and contrast structural components of the synaptic plasticity that underlies these two distinct forms of memory. In both cases, the structural changes involve time-dependent processes. Thus, some modifications are transient and may contribute to early formative stages of long-term memory, whereas others are more stable, longer lasting, and likely to confer persistence to memory storage. In addition, we explore the possibility that trans-synaptic signaling mechanisms governing de novo synapse formation during development can be reused in the adult for the purposes of structural synaptic plasticity and memory storage. Finally, we discuss how these mechanisms set in motion structural rearrangements that prepare a synapse to strengthen the same memory and, perhaps, to allow it to take part in other memories as a basis for understanding how their anatomical representation results in the enhanced expression and storage of memories in the brain.
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Hafner AS, Penn AC, Grillo-Bosch D, Retailleau N, Poujol C, Philippat A, Coussen F, Sainlos M, Opazo P, Choquet D. Lengthening of the Stargazin Cytoplasmic Tail Increases Synaptic Transmission by Promoting Interaction to Deeper Domains of PSD-95. Neuron 2015; 86:475-89. [PMID: 25843401 DOI: 10.1016/j.neuron.2015.03.013] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 11/17/2014] [Accepted: 02/23/2015] [Indexed: 11/28/2022]
Abstract
PSD-95 is a prominent organizer of the postsynaptic density (PSD) that can present a filamentous orientation perpendicular to the plasma membrane. Interactions between PSD-95 and transmembrane proteins might be particularly sensitive to this orientation, as "long" cytoplasmic tails might be required to reach deeper PSD-95 domains. Extension/retraction of transmembrane protein C-tails offer a new way of regulating binding to PSD-95. Using stargazin as a model, we found that enhancing the apparent length of stargazin C-tail through phosphorylation or by an artificial linker was sufficient to potentiate binding to PSD-95, AMPAR anchoring, and synaptic transmission. A linear extension of stargazin C-tail facilitates binding to PSD-95 by preferentially engaging interaction with the farthest located PDZ domains regarding to the plasma membrane, which present a greater affinity for the stargazin PDZ-domain-binding motif. Our study reveals that the concerted orientation of the stargazin C-tail and PSD-95 is a major determinant of synaptic strength.
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Affiliation(s)
- Anne-Sophie Hafner
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Andrew C Penn
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Dolors Grillo-Bosch
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Natacha Retailleau
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Christel Poujol
- Bordeaux Imaging Center, UMS 3420 CNRS, US4 INSERM, University of Bordeaux, 33000 Bordeaux, France
| | - Amandine Philippat
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Françoise Coussen
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Matthieu Sainlos
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Patricio Opazo
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France.
| | - Daniel Choquet
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; Bordeaux Imaging Center, UMS 3420 CNRS, US4 INSERM, University of Bordeaux, 33000 Bordeaux, France.
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Ruiz-DeDiego I, Mellstrom B, Vallejo M, Naranjo JR, Moratalla R. Activation of DREAM (downstream regulatory element antagonistic modulator), a calcium-binding protein, reduces L-DOPA-induced dyskinesias in mice. Biol Psychiatry 2015; 77:95-105. [PMID: 24857398 DOI: 10.1016/j.biopsych.2014.03.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 03/05/2014] [Accepted: 03/20/2014] [Indexed: 12/26/2022]
Abstract
BACKGROUND Previous studies have implicated the cyclic adenosine monophosphate/protein kinase A pathway as well as FosB and dynorphin-B expression mediated by dopamine D1 receptor stimulation in the development of 3,4-dihydroxyphenyl-L-alanine (L-DOPA)-induced dyskinesia. The magnitude of these molecular changes correlates with the intensity of dyskinesias. The calcium-binding protein downstream regulatory element antagonistic modulator (DREAM) binds to regulatory element sites called DRE in the DNA and represses transcription of target genes such as c-fos, fos-related antigen-2 (fra-2), and prodynorphin. This repression is released by calcium and protein kinase A activation. Dominant-active DREAM transgenic mice (daDREAM) and DREAM knockout mice (DREAM(-/-)) were used to define the involvement of DREAM in dyskinesias. METHODS Dyskinesias were evaluated twice a week in mice with 6-hydroxydopamine lesions during long-term L-DOPA (25 mg/kg) treatment. The impact of DREAM on L-DOPA efficacy was evaluated using the rotarod and the cylinder test after the establishment of dyskinesia and the molecular changes by immunohistochemistry and Western blot. RESULTS In daDREAM mice, L-DOPA-induced dyskinesia was decreased throughout the entire treatment. In correlation with these behavioral results, daDREAM mice showed a decrease in FosB, phosphoacetylated histone H3, dynorphin-B, and phosphorylated glutamate receptor subunit, type 1 expression. Conversely, genetic inactivation of DREAM potentiated the intensity of dyskinesia, and DREAM(-/-) mice exhibited an increase in expression of molecular markers associated with dyskinesias. The DREAM modifications did not affect the kinetic profile or antiparkinsonian efficacy of L-DOPA therapy. CONCLUSIONS The protein DREAM decreases development of L-DOPA-induced dyskinesia in mice and reduces L-DOPA-induced expression of FosB, phosphoacetylated histone H3, and dynorphin-B in the striatum. These data suggest that therapeutic approaches that activate DREAM may be useful to alleviate L-DOPA-induced dyskinesia without interfering with the therapeutic motor effects of L-DOPA.
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Affiliation(s)
- Irene Ruiz-DeDiego
- Cajal Institute, Madrid, Spain; Centro Nacional de Biotecnología, Madrid, Spain
| | - Britt Mellstrom
- Centro Nacional de Biotecnología, Madrid, Spain; Instituto de Investigaciones Biomédicas Alberto Sols all part of Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Mario Vallejo
- CIBERNED, Madrid, Spain; CIBERDEM, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Jose R Naranjo
- Centro Nacional de Biotecnología, Madrid, Spain; Instituto de Investigaciones Biomédicas Alberto Sols all part of Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Rosario Moratalla
- Cajal Institute, Madrid, Spain; Centro Nacional de Biotecnología, Madrid, Spain.
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Sanchez C, Asin KE, Artigas F. Vortioxetine, a novel antidepressant with multimodal activity: Review of preclinical and clinical data. Pharmacol Ther 2015; 145:43-57. [DOI: 10.1016/j.pharmthera.2014.07.001] [Citation(s) in RCA: 315] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 07/02/2014] [Indexed: 12/21/2022]
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Functional insight into development of positive allosteric modulators of AMPA receptors. Neuropharmacology 2014; 85:57-66. [PMID: 24878241 DOI: 10.1016/j.neuropharm.2014.05.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 05/02/2014] [Accepted: 05/15/2014] [Indexed: 11/22/2022]
Abstract
Positive allosteric modulators of α-amino-3-hydroxy-5-methyl-isoxazole-propionic acid (AMPA) ionotropic glutamate receptors facilitate synaptic plasticity and contribute essentially to learning and memory, properties which make AMPA receptors targets for drug discovery and development. One region at which several different classes of positive allosteric modulators bind lies at the dimer interface between the ligand-binding core of the second, membrane-proximal, extracellular domain of AMPA receptors. This solvent-accessible binding pocket has been the target of drug discovery efforts, leading to the recent delineation of five "subsites" which differentially allow access to modulator moieties, and for which distinct modulator affinities and apparent efficacies are attributed. Here we use the voltage-clamp technique in conjunction with rapid drug application to study the effects of mutants lining subsites "A" and "B" of the allosteric modulator pocket to assess affinity and efficacy of allosteric modulation by cyclothiazide, CX614, CMPDA and CMPDB. A novel analysis of the decay of current produced by the onset of desensitization has allowed us to estimate both affinity and efficacy from single concentrations of modulator. Such an approach may be useful for effective high throughput screening of new target compounds.
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Gerrow K, Triller A. GABAA receptor subunit composition and competition at synapses are tuned by GABAB receptor activity. Mol Cell Neurosci 2014; 60:97-107. [PMID: 24747870 DOI: 10.1016/j.mcn.2014.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 02/20/2014] [Accepted: 04/04/2014] [Indexed: 10/25/2022] Open
Abstract
GABABRs have a well-established role in controlling neuronal excitability and presynaptic neurotransmitter release. We examined the role of GABABR activity in modulating the number and lateral diffusion of GABAARs at inhibitory synapses. Changes in diffusion of GABAARs at synapses were observed when subunit heterogeneity was taken into account. While α1-GABAARs were unaffected, α2- and α5-GABAARs showed inverse changes in enrichment and diffusion. The intracellular TM3-4 loop of α2 was sufficient to observe the changes in diffusion by GABABR activity, whereas the loop of α5 was not. The opposing effect on α2- and α5-GABAARs was caused by a competition between GABAARs for binding slots at synapses. Receptor immobilization by cross-linking revealed that α5-GABAAR trapping at synapses is regulated by modulation of α2-GABAAR mobility. Finally, PKC activity was determined to be part of the signaling pathway through which GABABR activity modulates α2-GABAAR diffusion at synapses. These results outline a novel mechanism for tuning inhibitory transmission in a subunit-specific manner, and for the first time describe competition between GABAARs with different subunit compositions for binding slots at synapses.
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Affiliation(s)
- K Gerrow
- Institut de Biologie de l'ENS (IBENS), 46 rue d'Ulm, 75005 Paris, France
| | - A Triller
- Institut de Biologie de l'ENS (IBENS), 46 rue d'Ulm, 75005 Paris, France.
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38
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Kandel E, Dudai Y, Mayford M. The Molecular and Systems Biology of Memory. Cell 2014; 157:163-86. [DOI: 10.1016/j.cell.2014.03.001] [Citation(s) in RCA: 661] [Impact Index Per Article: 66.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Indexed: 01/04/2023]
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Kehoe LA, Bernardinelli Y, Muller D. GluN3A: an NMDA receptor subunit with exquisite properties and functions. Neural Plast 2013; 2013:145387. [PMID: 24386575 PMCID: PMC3872238 DOI: 10.1155/2013/145387] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/12/2013] [Indexed: 12/19/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDAR) are pivotal for synaptic plasticity and memory formation. Conventional NMDAR consist of heterotetrameric structures composed of GluN1 and GluN2 subunits. A third subunit, GluN3, can also assemble with NMDAR subunits giving a remarkable modification of their heteromeric structure, forming a "nonconventional" NMDAR. As a consequence, the stoichiometry and kinetic properties of the receptors are dramatically changed. Among the GluN3 family, the GluN3A subunit has been the focus of a large amount of studies during recent years. These studies reveal that GluN3A is transiently expressed during development and could play a role in the fine tuning of neuronal networks as well as associated diseases. Moreover, GluN3A distribution outside the postsynaptic densities, including perisynaptic astrocytes, places it at a strategic position to play an important role in the interactions between neurons and glial cells. This review highlights GluN3A properties and addresses its role in neurophysiology and associated pathologies.
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Affiliation(s)
- Laura A. Kehoe
- Department of Neuroscience, University of Geneva, CMU, 1211 Geneve 4, Switzerland
- Cellular Neurobiology, Departamento de Neurociencias, Centro de Investigacion Médica Aplicada (CIMA), Universidad de Navarra, 31008 Pamplona, Spain
| | - Yann Bernardinelli
- Department of Neuroscience, University of Geneva, CMU, 1211 Geneve 4, Switzerland
| | - Dominique Muller
- Department of Neuroscience, University of Geneva, CMU, 1211 Geneve 4, Switzerland
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Abstract
Spike timing-dependent plasticity (STDP) and other conventional Hebbian-type plasticity rules are prone to produce runaway dynamics of synaptic weights. Once potentiated, a synapse would have higher probability to lead to spikes and thus to be further potentiated, but once depressed, a synapse would tend to be further depressed. The runaway synaptic dynamics can be prevented by precisely balancing STDP rules for potentiation and depression; however, experimental evidence shows a great variety of potentiation and depression windows and magnitudes. Here we show that modifications of synapses to layer 2/3 pyramidal neurons from rat visual and auditory cortices in slices can be induced by intracellular tetanization: bursts of postsynaptic spikes without presynaptic stimulation. Induction of these heterosynaptic changes depended on the rise of intracellular calcium, and their direction and magnitude correlated with initial state of release mechanisms. We suggest that this type of plasticity serves as a mechanism that stabilizes the distribution of synaptic weights and prevents their runaway dynamics. To test this hypothesis, we develop a cortical neuron model implementing both homosynaptic (STDP) and heterosynaptic plasticity with properties matching the experimental data. We find that heterosynaptic plasticity effectively prevented runaway dynamics for the tested range of STDP and input parameters. Synaptic weights, although shifted from the original, remained normally distributed and nonsaturated. Our study presents a biophysically constrained model of how the interaction of different forms of plasticity--Hebbian and heterosynaptic--may prevent runaway synaptic dynamics and keep synaptic weights unsaturated and thus capable of further plastic changes and formation of new memories.
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Yang Y, Calakos N. Presynaptic long-term plasticity. Front Synaptic Neurosci 2013; 5:8. [PMID: 24146648 PMCID: PMC3797957 DOI: 10.3389/fnsyn.2013.00008] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 09/09/2013] [Indexed: 01/01/2023] Open
Abstract
Long-term synaptic plasticity is a major cellular substrate for learning, memory, and behavioral adaptation. Although early examples of long-term synaptic plasticity described a mechanism by which postsynaptic signal transduction was potentiated, it is now apparent that there is a vast array of mechanisms for long-term synaptic plasticity that involve modifications to either or both the presynaptic terminal and postsynaptic site. In this article, we discuss current and evolving approaches to identify presynaptic mechanisms as well as discuss their limitations. We next provide examples of the diverse circuits in which presynaptic forms of long-term synaptic plasticity have been described and discuss the potential contribution this form of plasticity might add to circuit function. Finally, we examine the present evidence for the molecular pathways and cellular events underlying presynaptic long-term synaptic plasticity.
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Affiliation(s)
- Ying Yang
- Department of Pediatrics, Stanford University School of Medicine Stanford, CA, USA
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Ahmad F, Kaila K, Blaesse P. Quantitative analysis of surface expression of membrane proteins using cold-adapted proteases. CURRENT PROTOCOLS IN PROTEIN SCIENCE 2013; 73:3.11.1-3.11.12. [PMID: 24510593 DOI: 10.1002/0471140864.ps0311s73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This unit presents an improved method for quantitative analysis of surface expression of membrane proteins utilizing a cold-adapted trypsin. Preservation of the proteolytic activity of the enzyme at 0° to 4°C allows cleavage of surface-expressed membrane proteins at temperatures at which trafficking of the mammalian plasmalemmal proteins is blocked. This provides an important advantage over established trypsin-cleavage protocols since it can be applied to membrane proteins with a fast turnover rate of the membrane pool and a fast recycling rate. Compared to surface biotinylation, the method is less time consuming.
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Affiliation(s)
- Faraz Ahmad
- Department of Biosciences and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Peter Blaesse
- Department of Biosciences and Neuroscience Center, University of Helsinki, Helsinki, Finland.,Institute of Physiology I, Westfälische Wilhelms-University Münster, Münster, Germany
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Palmitoylation-dependent regulation of glutamate receptors and their PDZ domain-containing partners. Biochem Soc Trans 2013; 41:72-8. [PMID: 23356261 DOI: 10.1042/bst20120223] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In recent years, it has become clear that both AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid)- and NMDA (N-methyl-D-aspartate)-type glutamate receptors, and many of their interacting partners, are palmitoylated proteins. Interfering with palmitoylation dramatically affects receptor trafficking and distribution and, in turn, can profoundly alter synaptic transmission. Increased knowledge of synaptic palmitoylation not only will aid our understanding of physiological neuronal regulation, but also may provide insights into, and even novel treatments for, neuropathological conditions. In the present paper, we review recent advances regarding the regulation of ionotropic glutamate receptor trafficking and function by palmitoylation.
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PKCλ is critical in AMPA receptor phosphorylation and synaptic incorporation during LTP. EMBO J 2013; 32:1365-80. [PMID: 23511975 DOI: 10.1038/emboj.2013.60] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 02/13/2013] [Indexed: 01/26/2023] Open
Abstract
Direct phosphorylation of GluA1 by PKC controls α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) receptor (AMPAR) incorporation into active synapses during long-term potentiation (LTP). Numerous signalling molecules that involved in AMPAR incorporation have been identified, but the specific PKC isoform(s) participating in GluA1 phosphorylation and the molecule triggering PKC activation remain largely unknown. Here, we report that the atypical isoform of PKC, PKCλ, is a critical molecule that acts downstream of phosphatidylinositol 3-kinase (PI3K) and is essential for LTP expression. PKCλ activation is required for both GluA1 phosphorylation and increased surface expression of AMPARs during LTP. Moreover, p62 interacts with both PKCλ and GluA1 during LTP and may serve as a scaffolding protein to place PKCλ in close proximity to facilitate GluA1 phosphorylation by PKCλ. Thus, we conclude that PKCλ is the critical signalling molecule responsible for GluA1-containing AMPAR phosphorylation and synaptic incorporation at activated synapses during LTP expression.
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Takkala P, Woodin MA. Muscarinic acetylcholine receptor activation prevents disinhibition-mediated LTP in the hippocampus. Front Cell Neurosci 2013; 7:16. [PMID: 23450426 PMCID: PMC3584297 DOI: 10.3389/fncel.2013.00016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 02/08/2013] [Indexed: 11/13/2022] Open
Abstract
Disinhibition-mediated long-term potentiation (LTP) in the CA1 region of the hippocampus involves GABAergic synaptic plasticity at feedforward inhibitory inputs, resulting in the reduced shunting of glutamatergic excitatory currents. The GABAergic plasticity which underlies disinhibition-mediated LTP results from a Ca(2+)-dependent decrease in the activity of the K(+)-Cl(-) cotransporter (KCC2), depolarizing the reversal potential for GABAA receptor-mediated currents (EGABA), thereby attenuating inhibition. Muscarinic acetylcholine receptor (mAChR) activation has previously been shown to regulate classic glutamatergic LTP, modulate intracellular [Ca(2+)] and signaling, and facilitate the excitability of GABAergic interneurons in the CA1. Based on these effects, and the ability of mAChR activation to regulate CA1 pyramidal neuron KCC2 expression, we proposed that mAChR activation would modulate disinhibition-mediated LTP. To test this prediction, we made whole cell recordings from CA1 pyramidal neurons in hippocampal slices. Disinhibition-mediated LTP was induced using a spike timing-dependent plasticity (STDP) protocol, which involved coincident pre-synaptic stimulation and post-synaptic current injection (at 5 Hz for 60 s). We found that mAChR activation via carbachol (CCh) prevented the induction of disinhibition-mediated LTP. Moreover, in the presence of CCh, EGABA failed to depolarize following plasticity induction. Lastly, we recorded the paired-pulse ratio (PPR) during the induction of disinhibition-mediated LTP and found that in the presence of CCh, plasticity induction induced a significant paired-pulse depression. This suggests that pre-synaptic mAChR activation may prevent the post-synaptic expression of disinhibition-mediated LTP.
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Affiliation(s)
- Petri Takkala
- Department of Cell and Systems Biology, University of Toronto Toronto, ON, Canada
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Abstract
The presynaptic source of dopamine in the CA1 field of dorsal hippocampus is uncertain due to an anatomical mismatch between dopaminergic terminals and receptors. We show, in an in vitro slice preparation from C57BL/6 male mice, that a dopamine (DA) D1 receptor (D1R)-mediated enhancement in glutamate synaptic transmission occurs following release of endogenous DA with amphetamine exposure. It is assumed DA is released from terminals innervating from the ventral tegmental area (VTA) even though DA transporter (DAT)-positive fibers are absent in hippocampus, a region with abundant D1Rs. It has been suggested this results from a lack of DAT expression on VTA terminals rather than a lack of these terminals per se. Neither a knockdown of tyrosine hydroxylase (TH) expression in the VTA by THsiRNA, delivered locally, by adeno-associated viral vector, nor localized pharmacological blockade of DAT to prevent amphetamine uptake into DA terminals, has any effect on the D1R synaptic, enhancement response to amphetamine. However, either a decrease in TH expression in the locus ceruleus (LC) or a blockade of the norepinephrine (NE) transporter prevents the DA-mediated response, indicating LC terminals can release both NE and DA. These findings suggest noradrenergic fibers may be the primary source of DA release in hippocampus and corresponding DA-mediated increase in synaptic transmission. Accordingly, these data imply the LC may have a role in DA transmission in the CNS in response to drugs of abuse, and potentially, under physiological conditions.
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Pereda AE, Curti S, Hoge G, Cachope R, Flores CE, Rash JE. Gap junction-mediated electrical transmission: regulatory mechanisms and plasticity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:134-46. [PMID: 22659675 DOI: 10.1016/j.bbamem.2012.05.026] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 05/16/2012] [Accepted: 05/23/2012] [Indexed: 02/08/2023]
Abstract
The term synapse applies to cellular specializations that articulate the processing of information within neural circuits by providing a mechanism for the transfer of information between two different neurons. There are two main modalities of synaptic transmission: chemical and electrical. While most efforts have been dedicated to the understanding of the properties and modifiability of chemical transmission, less is still known regarding the plastic properties of electrical synapses, whose structural correlate is the gap junction. A wealth of data indicates that, rather than passive intercellular channels, electrical synapses are more dynamic and modifiable than was generally perceived. This article will discuss the factors determining the strength of electrical transmission and review current evidence demonstrating its dynamic properties. Like their chemical counterparts, electrical synapses can also be plastic and modifiable. This article is part of a Special Issue entitled: The Communicating junctions, roles and dysfunctions.
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Affiliation(s)
- Alberto E Pereda
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.
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Chistiakova M, Volgushev M. Heterosynaptic plasticity in the neocortex. Exp Brain Res 2012; 199:377-90. [PMID: 19499213 PMCID: PMC2781103 DOI: 10.1007/s00221-009-1859-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Accepted: 05/12/2009] [Indexed: 01/25/2023]
Abstract
Ongoing learning continuously shapes the distribution of neurons’ synaptic weights in a system with plastic synapses. Plasticity may change the weights of synapses that were active during the induction—homosynaptic changes, but also may change synapses not active during the induction—heterosynaptic changes. Here we will argue, that heterosynaptic and homosynaptic plasticity are complementary processes, and that heterosynaptic plasticity might accompany homosynaptic plasticity induced by typical pairing protocols. Synapses are not uniform in their susceptibility for plastic changes, but have predispositions to undergo potentiation or depression, or not to change. Predisposition is one of the factors determining the direction and magnitude of homo- and heterosynaptic changes. Heterosynaptic changes which take place according to predispositions for plasticity may provide a useful mechanism(s) for homeostasis of neurons’ synaptic weights and extending the lifetime of memory traces during ongoing learning in neuronal networks.
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Regulation of AMPA receptor surface diffusion by PSD-95 slots. Curr Opin Neurobiol 2011; 22:453-60. [PMID: 22051694 DOI: 10.1016/j.conb.2011.10.010] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 10/09/2011] [Accepted: 10/10/2011] [Indexed: 11/20/2022]
Abstract
Excitatory synaptic transmission is largely mediated by AMPA receptors (AMPARs) present at the postsynaptic density. Recent studies in single molecule tracking of AMPAR has revealed that extrasynaptic AMPARs are highly mobile and thus might serve as a readily available pool for their synaptic recruitment during synaptic plasticity events such as long-term potentiation (LTP). Because this hypothesis relies on the cell's ability to increase the number of diffusional traps or 'slots' at synapses during LTP, we will review a number of protein-protein interactions that might impact AMPARs lateral diffusion and thus potentially serve as slots. Recent studies have identified the interaction between the AMPAR-Stargazin complex and PSD-95 as the minimal components of the diffusional trapping slot. We will overview the molecular basis of this critical interaction, its activity-dependent regulation and its potential contribution to LTP.
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Abstract
Synaptic incorporation of NMDA receptors (NMDARs) is regulated by GluN2 subunits with different rules controlling GluN2A- and GluN2B-containing receptors; whereas GluN2B-containing receptors are constitutively incorporated into synapses, GluN2A incorporation is activity-dependent. We expressed electrophysiologically tagged NMDARs in rat hippocampal slices to identify the molecular determinants controlling the mode of synaptic incorporation of NMDARs. Expressing chimeric GluN2 subunits, we identified a putative N-glycosylation site present in GluN2B, but not in GluN2A, as necessary and sufficient to drive NMDARs into synapses in an activity-independent manner. This suggests a novel mechanism for regulating activity-driven changes and trafficking of NMDARs to the synapse.
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