1
|
Eltokhi A, Lundstrom BN, Li J, Zweifel LS, Catterall WA, Gamal El-Din TM. Pathogenic gating pore current conducted by autism-related mutations in the Na V1.2 brain sodium channel. Proc Natl Acad Sci U S A 2024; 121:e2317769121. [PMID: 38564633 PMCID: PMC11009634 DOI: 10.1073/pnas.2317769121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 02/26/2024] [Indexed: 04/04/2024] Open
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by social and communication deficits and repetitive behaviors. The genetic heterogeneity of ASD presents a challenge to the development of an effective treatment targeting the underlying molecular defects. ASD gating charge mutations in the KCNQ/KV7 potassium channel cause gating pore currents (Igp) and impair action potential (AP) firing of dopaminergic neurons in brain slices. Here, we investigated ASD gating charge mutations of the voltage-gated SCN2A/NaV1.2 brain sodium channel, which ranked high among the ion channel genes with mutations in individuals with ASD. Our results show that ASD mutations in the gating charges R2 in Domain-II (R853Q), and R1 (R1626Q) and R2 (R1629H) in Domain-IV of NaV1.2 caused Igp in the resting state of ~0.1% of the amplitude of central pore current. The R1626Q mutant also caused significant changes in the voltage dependence of fast inactivation, and the R1629H mutant conducted proton-selective Igp. These potentially pathogenic Igp were exacerbated by the absence of the extracellular Mg2+ and Ca2+. In silico simulation of the effects of these mutations in a conductance-based single-compartment cortical neuron model suggests that the inward Igp reduces the time to peak for the first AP in a train, increases AP rates during a train of stimuli, and reduces the interstimulus interval between consecutive APs, consistent with increased neural excitability and altered input/output relationships. Understanding this common pathophysiological mechanism among different voltage-gated ion channels at the circuit level will give insights into the underlying mechanisms of ASD.
Collapse
Affiliation(s)
- Ahmed Eltokhi
- Department of Pharmacology, University of Washington, Seattle, WA98195
| | - Brian Nils Lundstrom
- Department of Neurology in the Division of Epilepsy, Mayo Clinic, Rochester, MN55905
| | - Jin Li
- Department of Pharmacology, University of Washington, Seattle, WA98195
| | - Larry S. Zweifel
- Department of Pharmacology, University of Washington, Seattle, WA98195
- Department of Psychiatry & Behavioral Sciences, University of Washington, Seattle, WA98195
| | | | | |
Collapse
|
2
|
Tan S, Mo X, Qin H, Dong B, Zhou J, Long C, Yang L. Biocytin-Labeling in Whole-Cell Recording: Electrophysiological and Morphological Properties of Pyramidal Neurons in CYLD-Deficient Mice. Molecules 2023; 28:molecules28104092. [PMID: 37241833 DOI: 10.3390/molecules28104092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/27/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Biocytin, a chemical compound that is an amide formed from the vitamin biotin and the amino acid L-lysine, has been used as a histological dye to stain nerve cells. Electrophysiological activity and morphology are two key characteristics of neurons, but revealing both the electrophysiological and morphological properties of the same neuron is challenging. This article introduces a detailed and easy-to-operate procedure for single-cell labeling in combination with whole-cell patch-clamp recording. Using a recording electrode filled with a biocytin-containing internal solution, we demonstrate the electrophysiological and morphological characteristics of pyramidal (PNs), medial spiny (MSNs) and parvalbumin neurons (PVs) in brain slices, where the electrophysiological and morphological properties of the same individual cell are elucidated. We first introduce a protocol for whole-cell patch-clamp recording in various neurons, coupled with the intracellular diffusion of biocytin delivered by the glass capillary of the recording electrode, followed by a post hoc procedure to reveal the architecture and morphology of biocytin-labeled neurons. An analysis of action potentials (APs) and neuronal morphology, including the dendritic length, number of intersections, and spine density of biocytin-labeled neurons, were performed using ClampFit and Fiji Image (ImageJ), respectively. Next, to take advantage of the techniques introduced above, we uncovered defects in the APs and the dendritic spines of PNs in the primary motor cortex (M1) of deubiquitinase cylindromatosis (CYLD) knock-out (Cyld-/-) mice. In summary, this article provides a detailed methodology for revealing the morphology as well as the electrophysiological activity of a single neuron that will have many applications in neurobiology.
Collapse
Affiliation(s)
- Shuyi Tan
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
- School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Xiuping Mo
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Huihui Qin
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Binbin Dong
- School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Jiankui Zhou
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| | - Cheng Long
- School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Li Yang
- School of Life Sciences, Guangzhou University, Guangzhou 510006, China
| |
Collapse
|
3
|
Lightning A, Bourzeix M, Beurrier C, Kuczewski N. Effects of discontinuous blue light stimulation on the electrophysiological properties of neurons lacking opsin expression in vitro: Implications for optogenetic experiments. Eur J Neurosci 2023; 57:885-899. [PMID: 36726326 DOI: 10.1111/ejn.15927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 01/05/2023] [Accepted: 01/26/2023] [Indexed: 02/03/2023]
Abstract
Neuronal sensitivity to light stimulation can be a significant confounding factor for assays that use light to study neuronal processes, such as optogenetics and fluorescent imaging. While continuous one-photon (1P) blue light stimulation has been shown to be responsible for a decrease in firing activity in several neuronal subtypes, discontinuous 1P blue light stimulation commonly used in optogenetic experiments is supposed to have a negligible action. In the present report, we tested experimentally this theoretical prediction by assessing the effects produced by the most commonly used patterns of discontinuous 1P light stimulation on several electrophysiological parameters in brain slices. We found that, compared with continuous stimulation, the artefactual effect of light is reduced when discontinuous stimulation is used, especially when the duty cycle and light power are low.
Collapse
Affiliation(s)
- Anistasha Lightning
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028UMR5292, NEUROPOP, Bron, France
| | - Marie Bourzeix
- Aix Marseille Univ, CNRS UMR 7289, Institut de Neurosciences de la Timone (INT), Marseille, France
| | - Corinne Beurrier
- Aix Marseille Univ, CNRS UMR 7289, Institut de Neurosciences de la Timone (INT), Marseille, France
| | - Nicola Kuczewski
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028UMR5292, NEUROPOP, Bron, France
| |
Collapse
|
4
|
Zhou L, Wang K, Xu Y, Dong BB, Wu DC, Wang ZX, Wang XT, Cai XY, Yang JT, Zheng R, Chen W, Shen Y, Wei JS. A patient-derived mutation of epilepsy-linked LGI1 increases seizure susceptibility through regulating K v1.1. Cell Biosci 2023; 13:34. [PMID: 36804022 PMCID: PMC9940402 DOI: 10.1186/s13578-023-00983-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 02/04/2023] [Indexed: 02/22/2023] Open
Abstract
BACKGROUND Autosomal dominant lateral temporal epilepsy (ADLTE) is an inherited syndrome caused by mutations in the leucine-rich glioma inactivated 1 (LGI1) gene. It is known that functional LGI1 is secreted by excitatory neurons, GABAergic interneurons, and astrocytes, and regulates AMPA-type glutamate receptor-mediated synaptic transmission by binding ADAM22 and ADAM23. However, > 40 LGI1 mutations have been reported in familial ADLTE patients, more than half of which are secretion-defective. How these secretion-defective LGI1 mutations lead to epilepsy is unknown. RESULTS We identified a novel secretion-defective LGI1 mutation from a Chinese ADLTE family, LGI1-W183R. We specifically expressed mutant LGI1W183R in excitatory neurons lacking natural LGI1, and found that this mutation downregulated Kv1.1 activity, led to neuronal hyperexcitability and irregular spiking, and increased epilepsy susceptibility in mice. Further analysis revealed that restoring Kv1.1 in excitatory neurons rescued the defect of spiking capacity, improved epilepsy susceptibility, and prolonged the life-span of mice. CONCLUSIONS These results describe a role of secretion-defective LGI1 in maintaining neuronal excitability and reveal a new mechanism in the pathology of LGI1 mutation-related epilepsy.
Collapse
Affiliation(s)
- Lin Zhou
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Kang Wang
- grid.452661.20000 0004 1803 6319Department of Neurology, First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310003 China
| | - Yuxiang Xu
- grid.256922.80000 0000 9139 560XSchool of Life Sciences, Henan University, Kaifeng, 475004 China
| | - Bin-Bin Dong
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Deng-Chang Wu
- grid.452661.20000 0004 1803 6319Department of Neurology, First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310003 China
| | - Zhao-Xiang Wang
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Xin-Tai Wang
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Xin-Yu Cai
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Jin-Tao Yang
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Rui Zheng
- grid.13402.340000 0004 1759 700XDepartment of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020 China
| | - Wei Chen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020, China.
| | - Ying Shen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310020, China.
| | - Jian-She Wei
- School of Life Sciences, Henan University, Kaifeng, 475004, China.
| |
Collapse
|
5
|
Afterhyperpolarization Promotes the Firing of Mitral Cells through a Voltage-Dependent Modification of Action Potential Threshold. eNeuro 2022; 9:ENEURO.0401-21.2021. [PMID: 35277450 PMCID: PMC8982644 DOI: 10.1523/eneuro.0401-21.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/22/2021] [Accepted: 12/13/2021] [Indexed: 11/21/2022] Open
Abstract
In the olfactory bulb, mitral cells (MCs) display a spontaneous firing that is characterized by bursts of action potentials (APs) intermixed with silent periods. Intraburst firing frequency and duration are heterogeneous among MCs and increase with membrane depolarization. By using patch-clamp recording on rat slices, we dissected out the intrinsic properties responsible for this bursting activity. We showed that the threshold of AP generation dynamically changes as a function of the preceding trajectory of the membrane potential. In fact, the AP threshold became more negative when the membrane was hyperpolarized and had a recovery rate inversely proportional to the membrane repolarization rate. Such variations appeared to be produced by changes in the inactivation state of voltage-dependent Na+ channels. Thus, AP initiation was favored by hyperpolarizing events, such as negative membrane oscillations or inhibitory synaptic input. After the first AP, the following fast afterhyperpolarization (AHP) brought the threshold to more negative values and then promoted the emission of the following AP. This phenomenon was repeated for each AP of the burst making the fast AHP a regenerative mechanism that sustained the firing, AHP with larger amplitudes and faster repolarizations being associated with larger and higher-frequency bursts. Burst termination was found to be because of the development of a slow repolarization component of the AHP (slow AHP). Overall, the AHP characteristics appeared as a major determinant of the bursting properties.
Collapse
|
6
|
Tufo C, Poopalasundaram S, Dorrego-Rivas A, Ford MC, Graham A, Grubb MS. Development of the mammalian main olfactory bulb. Development 2022; 149:274348. [PMID: 35147186 PMCID: PMC8918810 DOI: 10.1242/dev.200210] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The mammalian main olfactory bulb is a crucial processing centre for the sense of smell. The olfactory bulb forms early during development and is functional from birth. However, the olfactory system continues to mature and change throughout life as a target of constitutive adult neurogenesis. Our Review synthesises current knowledge of prenatal, postnatal and adult olfactory bulb development, focusing on the maturation, morphology, functions and interactions of its diverse constituent glutamatergic and GABAergic cell types. We highlight not only the great advances in the understanding of olfactory bulb development made in recent years, but also the gaps in our present knowledge that most urgently require addressing. Summary: This Review describes the morphological and functional maturation of cells in the mammalian main olfactory bulb, from embryonic development to adult neurogenesis.
Collapse
Affiliation(s)
- Candida Tufo
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Subathra Poopalasundaram
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Ana Dorrego-Rivas
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Marc C Ford
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Anthony Graham
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Matthew S Grubb
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| |
Collapse
|
7
|
Yu L, Chu C, Yuan Y, Guo X, Lei C, Sheng H, Yang L, Cui D, Lai B, Zheng P. Activity in projection neurons from prelimbic cortex to the PVT is necessary for retrieval of morphine withdrawal memory. Cell Rep 2021; 35:108958. [PMID: 33826893 DOI: 10.1016/j.celrep.2021.108958] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 12/28/2020] [Accepted: 03/17/2021] [Indexed: 11/25/2022] Open
Abstract
Previous work has shown that the paraventricular nucleus of the thalamus (PVT) is an important region that is involved in the conditioned context-induced retrieval of morphine withdrawal memory. However, the upstream neural circuits that activate the PVT to participate in the conditioned context-induced retrieval of morphine withdrawal memory remain unknown. In the present work, we find that the conditioned context activates projection neurons from the prelimbic cortex (PrL) to the PVT, and the inhibition of PrL-PVT projection neurons inhibits the conditioned context-induced retrieval of morphine withdrawal memory; the conditioned context induces an increase in Arc expression, intrinsic excitability, and glutamate output in PrL-PVT projection neurons in morphine-withdrawn mice. These results suggest that the activity of PrL-PVT projection neurons is necessary for the retrieval of morphine withdrawal memory, and the conditioned context causes a plastic change in the activity in these projection neurons during the withdrawal memory retrieval.
Collapse
Affiliation(s)
- Lanfang Yu
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Chenshan Chu
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Yu Yuan
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Xinli Guo
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Chao Lei
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Huan Sheng
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Li Yang
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Dongyang Cui
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Bin Lai
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
| | - Ping Zheng
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China; Department of Neurology of Zhongshan Hospital, MOE Frontier Center for Brain Science, School of Basic Medical Sciences, Shanghai, China.
| |
Collapse
|
8
|
Lage-Rupprecht V, Zhou L, Bianchini G, Aghvami SS, Mueller M, Rózsa B, Sassoè-Pognetto M, Egger V. Presynaptic NMDARs cooperate with local spikes toward GABA release from the reciprocal olfactory bulb granule cell spine. eLife 2020; 9:e63737. [PMID: 33252329 PMCID: PMC7704106 DOI: 10.7554/elife.63737] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/10/2020] [Indexed: 12/16/2022] Open
Abstract
In the rodent olfactory bulb the smooth dendrites of the principal glutamatergic mitral cells (MCs) form reciprocal dendrodendritic synapses with large spines on GABAergic granule cells (GC), where unitary release of glutamate can trigger postsynaptic local activation of voltage-gated Na+-channels (Navs), that is a spine spike. Can such single MC input evoke reciprocal release? We find that unitary-like activation via two-photon uncaging of glutamate causes GC spines to release GABA both synchronously and asynchronously onto MC dendrites. This release indeed requires activation of Navs and high-voltage-activated Ca2+-channels (HVACCs), but also of NMDA receptors (NMDAR). Simulations show temporally overlapping HVACC- and NMDAR-mediated Ca2+-currents during the spine spike, and ultrastructural data prove NMDAR presence within the GABAergic presynapse. This cooperative action of presynaptic NMDARs allows to implement synapse-specific, activity-dependent lateral inhibition, and thus could provide an efficient solution to combinatorial percept synthesis in a sensory system with many receptor channels.
Collapse
Affiliation(s)
- Vanessa Lage-Rupprecht
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
- Department of Bioinformatics, Fraunhofer SCAISankt AugustinGermany
| | - Li Zhou
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
| | - Gaia Bianchini
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
| | - S Sara Aghvami
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
- School of Electrical and Computer Engineering, University of TehranTehranIslamic Republic of Iran
- School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM)TehranIslamic Republic of Iran
| | - Max Mueller
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
| | - Balázs Rózsa
- Two-Photon Imaging Center, Institute of Experimental Medicine, Hungarian Academy of SciencesBudapestHungary
| | | | - Veronica Egger
- Neurophysiology, Institute of Zoology, Universität RegensburgRegensburgGermany
| |
Collapse
|
9
|
Meiser S, Ashida G, Kretzberg J. Non-synaptic Plasticity in Leech Touch Cells. Front Physiol 2019; 10:1444. [PMID: 31827443 PMCID: PMC6890822 DOI: 10.3389/fphys.2019.01444] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/08/2019] [Indexed: 01/06/2023] Open
Abstract
The role of Na+/K+-pumps in activity-dependent synaptic plasticity has been described in both vertebrates and invertebrates. Here, we provide evidence that the Na+/K+-pump is also involved in activity-dependent non-synaptic cellular plasticity in leech sensory neurons. We show that the resting membrane potential (RMP) of T cells hyperpolarizes in response to repeated somatic current injection, while at the same time their spike count (SC) and the input resistance (IR) increase. Our Hodgkin–Huxley-type neuron model, adjusted to physiological T cell properties, suggests that repetitive action potential discharges lead to increased Na+/K+-pump activity, which then hyperpolarizes the RMP. In consequence, a slow, non-inactivating current decreases, which is presumably mediated by voltage-dependent, low-threshold potassium channels. Closing of these putative M-type channels due to hyperpolarization of the resting potential increases the IR of the cell, leading to a larger number of spikes. By this mechanism, the response behavior switches from rapidly to slowly adapting spiking. These changes in spiking behavior also effect other T cells on the same side of the ganglion, which are connected via a combination of electrical and chemical synapses. An increased SC in the presynaptic T cell results in larger postsynaptic responses (PRs) in the other T cells. However, when the number of elicited presynaptic spikes is kept constant, the PR does not change. These results suggest that T cells change their responses in an activity-dependent manner through non-synaptic rather than synaptic plasticity. These changes might act as a gain-control mechanism. Depending on the previous activity, this gain could scale the relative impacts of synaptic inputs from other mechanoreceptors, versus the spike responses to tactile skin stimulation. This multi-tasking ability, and its flexible adaptation to previous activity, might make the T cell a key player in a preparatory network, enabling the leech to perform fast behavioral reactions to skin stimulation.
Collapse
Affiliation(s)
- Sonja Meiser
- Computational Neuroscience, Department of Neuroscience, Faculty VI, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - Go Ashida
- Computational Neuroscience, Department of Neuroscience, Faculty VI, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany.,Cluster of Excellence Hearing4all, Department of Neuroscience, Faculty VI, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - Jutta Kretzberg
- Computational Neuroscience, Department of Neuroscience, Faculty VI, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany.,Cluster of Excellence Hearing4all, Department of Neuroscience, Faculty VI, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| |
Collapse
|
10
|
Tamadon H, Ghasemi Z, Ghasemi F, Hosseinmardi N, Vatanpour H, Janahmadi M. Characterization of Functional Effects of Two New Active Fractions Isolated From Scorpion Venom on Neuronal Ca 2+ Spikes: A Possible Action on Ca 2+-Dependent Dependent K + Channels. Basic Clin Neurosci 2019. [PMID: 31031893 PMCID: PMC6484188 DOI: 10.32598/bcn.9.10.352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION It is a long time that natural toxin research is conducted to unlock the medical potential of toxins. Although venoms-toxins cause pathophysiological conditions, they may be effective to treat several diseases. Since toxins including scorpion toxins target voltage-gated ion channels, they may have profound effects on excitable cells. Therefore, elucidating the cellular and electrophysiological impacts of toxins, particularly scorpion toxins would be helpful in future drug development opportunities. METHODS Intracellular recording was made from F1 cells of Helix aspersa in the presence of calcium Ringer solution in which Na+ and K+ channels were blocked. Then, the modulation of channel function in the presence of extracellular application of F4 and F6 toxins and kaliotoxin (KTX; 50 nM and 1 μM) was examined by assessing the electrophysiological characteristics of calcium spikes. RESULTS The two active toxin fractions, similar to KTX, a known Ca2+-activated K+ channel blocker, reduced the amplitude of AHP, enhanced the firing frequency of calcium spikes and broadened the duration of Ca2+ spikes. Therefore, it might be inferred that these two new fractions induce neuronal hyperexcitability possibly, in part, by blocking calcium-activated potassium channel current. However, this supposition requires further investigation using voltage clamping technique. CONCLUSION These toxin fractions may act as blocker of calcium-activated potassium channels.
Collapse
Affiliation(s)
- Hanieh Tamadon
- Department of Physiology, Neuroscience Research Center,
School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zahra Ghasemi
- Department of Physiology, School of Medicine, Tarbiat
Modares University, Tehran, Iran
| | - Fatemeh Ghasemi
- Department of Physiology, Neuroscience Research Center,
School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Narges Hosseinmardi
- Department of Physiology, Neuroscience Research Center,
School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Vatanpour
- Department of Toxicology and Pharmacology, School of
Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadi
- Department of Physiology, Neuroscience Research Center,
School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Corresponding Author: Mahyar
Janahmadi, PhD.Address: Department of Physiology, Neuroscience Research
Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Tel: +98 (21) 22439971
E-mail:;
| |
Collapse
|
11
|
Ait Ouares K, Beurrier C, Canepari M, Laverne G, Kuczewski N. Opto nongenetics inhibition of neuronal firing. Eur J Neurosci 2018; 49:6-26. [PMID: 30387216 DOI: 10.1111/ejn.14251] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/07/2018] [Accepted: 09/14/2018] [Indexed: 01/28/2023]
Abstract
Optogenetics is based on the selective expression of exogenous opsins by neurons allowing experimental control of their electrical activity using visible light. The interpretation of the results of optogenetic experiments is based on the assumption that light stimulation selectively acts on those neurons expressing the exogenous opsins without perturbing the activity of naive ones. Here, we report that light stimulation, of wavelengths and power in the range of those normally used in optogenetic experiments, consistently reduces the firing activity of naive Mitral Cells (MCs) and Tufted Neurons in the olfactory bulb as well as in Medium Spiny Neurons (MSNs) in the striatum. No such effect was observed for cerebellar Purkinje and hippocampal CA1 neurons. The effects on MC firing appear to be mainly due to a light-induced increase in tissue temperature, between 0.1 and 0.4°C, associated with the generation of a hyperpolarizing current and a modification of action potential (AP) shape. Therefore, light in the visible range can affect neuronal physiology in a cell-specific manner. Beside the implications for optogenetic studies, our results pave the way to investigating the use of visible light for therapeutic purposes in pathologies associated with neuronal hyperexcitability.
Collapse
Affiliation(s)
- Karima Ait Ouares
- Univ. Grenoble Alpes, CNRS, LIPhy, Grenoble, France.,Laboratories of Excellence, Ion Channel Science and Therapeutics, Grenoble, France
| | - Corinne Beurrier
- Univ. Grenoble Alpes, CNRS, LIPhy, Grenoble, France.,Laboratories of Excellence, Ion Channel Science and Therapeutics, Grenoble, France.,Aix Marseille University, CNRS, IBDM, Marseille, France
| | - Marco Canepari
- Univ. Grenoble Alpes, CNRS, LIPhy, Grenoble, France.,Laboratories of Excellence, Ion Channel Science and Therapeutics, Grenoble, France.,Institut National de la Santé et Recherche Médicale, Paris, France
| | | | - Nicola Kuczewski
- CNRS, UMR 5292, INSERM, U1028, Lyon, France.,Lyon Neuroscience Research Center, Neuroplasticity and neuropathology of olfactory perception Team, Lyon, France.,University Lyon, Lyon, Franc.,University Lyon1, Villeurbanne, France
| |
Collapse
|
12
|
Reuveni I, Barkai E. Tune it in: mechanisms and computational significance of neuron-autonomous plasticity. J Neurophysiol 2018; 120:1781-1795. [DOI: 10.1152/jn.00102.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The activity of a neural network is a result of synaptic signals that convey the communication between neurons and neuron-based intrinsic currents that determine the neuron’s input-output transfer function. Ample studies have demonstrated that cell-based excitability, and in particular intrinsic excitability, is modulated by learning and that these modifications play a key role in learning-related behavioral changes. The field of cell-based plasticity is largely growing, and it entails numerous experimental findings that demonstrate a large diversity of currents that are affected by learning. The diverse effect of learning on the neuron’s excitability emphasizes the need for a framework under which cell-based plasticity can be categorized to enable the assessment of the computational roles of the intrinsic modifications. We divide the domain of cell-based plasticity into three main categories, where the first category entails the currents that mediate the passive properties and single-spike generation, the second category entails the currents that mediate spike frequency adaptation, and the third category entails a novel learning-induced mechanism where all excitatory and inhibitory synapses double their strength. Curiously, this elementary division enables a natural categorization of the computational roles of these learning-induced plasticities. The computational roles are diverse and include modification of the neuronal mode of action, such as bursting, prolonged, and fast responsive; attention-like effect where the signal detection is improved; transfer of the network into an active state; biasing the competition for memory allocation; and transforming an environmental cue into a dominant cue and enabling a quicker formation of new memories.
Collapse
Affiliation(s)
- Iris Reuveni
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Edi Barkai
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| |
Collapse
|
13
|
Ghasemi F, Tamadon H, Hosseinmardi N, Janahmadi M. Effects of Dorema ammoniacum Gum on Neuronal Epileptiform Activity-Induced by Pentylenetetrazole. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH : IJPR 2018; 17:735-742. [PMID: 29881430 PMCID: PMC5985190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Epilepsy is a chronic neurological disease which disrupts the neuronal electrical activity. One-third of patients are resistant to treatment with available antiepileptic agents. The use of herbal medicine for treating several diseases including epilepsy is on the rise. Therefore, further investigation is required to verify the safety and effectiveness of Phytomedicine in treating diseases. The current study is an attempt to elucidate the electrophysiological mechanism of the effect of Dorema ammoniacum gum on a cellular model of epilepsy, using intracellular recording method. The gum was applied either after or before pentylenetetrazole, as an epileptic drug, in order to explore the possible therapeutic and preventive effects of gum. Treatment with D. ammoniacum gum alone increased the neuronal excitability and when applied before or after treatment with PTZ not only did not prevent or change the electrophysiological changes induced by PTZ but also re-enhanced the induction of hyperexcitability and epileptiform activity through depolarizing membrane potential, increasing the firing frequency and decreasing the AHP amplitude. However, phenobarbital, as a standard anti-epileptic agent, almost reversed the effect of PTZ and preserved the normal firing properties of F1 neurons. The possible candidate mechanism of the effect of gum on neuronal excitability could be suppressive effects of gum on voltage and/or Ca2+ dependent K+ channels currents underlying AHP.
Collapse
Affiliation(s)
- Fatemeh Ghasemi
- Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Evin, Tehran, Iran.
| | - Hanieh Tamadon
- Neuroscience Research Center, Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Evin, Tehran, Iran.
| | - Narges Hosseinmardi
- Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Evin, Tehran, Iran. ,Neuroscience Research Center, Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Evin, Tehran, Iran.
| | - Mahyar Janahmadi
- Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Evin, Tehran, Iran. ,Neuroscience Research Center, Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Evin, Tehran, Iran.,Corresponding author: E-mail:
| |
Collapse
|
14
|
Liu S, Puche AC, Shipley MT. The Interglomerular Circuit Potently Inhibits Olfactory Bulb Output Neurons by Both Direct and Indirect Pathways. J Neurosci 2016; 36:9604-17. [PMID: 27629712 PMCID: PMC5039244 DOI: 10.1523/jneurosci.1763-16.2016] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/07/2016] [Accepted: 07/28/2016] [Indexed: 01/13/2023] Open
Abstract
UNLABELLED Sensory processing shapes our perception. In mammals, odor information is encoded by combinatorial activity patterns of olfactory bulb (OB) glomeruli. Glomeruli are richly interconnected by short axon cells (SACs), which form the interglomerular circuit (IGC). It is unclear how the IGC impacts OB output to downstream neural circuits. We combined in vitro and in vivo electrophysiology with optogenetics in mice and found the following: (1) the IGC potently and monosynaptically inhibits the OB output neurons mitral/tufted cells (MTCs) by GABA release from SACs: (2) gap junction-mediated electrical coupling is strong for the SAC→MTC synapse, but negligible for the SAC→ETC synapse; (3) brief IGC-mediated inhibition is temporally prolonged by the intrinsic properties of MTCs; and (4) sniff frequency IGC activation in vivo generates persistent MTC inhibition. These findings suggest that the temporal sequence of glomerular activation by sensory input determines which stimulus features are transmitted to downstream olfactory networks and those filtered by lateral inhibition. SIGNIFICANCE STATEMENT Odor identity is encoded by combinatorial patterns of activated glomeruli, the initial signal transformation site of the olfactory system. Lateral circuit processing among activated glomeruli modulates olfactory signal transformation before transmission to higher brain centers. Using a combination of in vitro and in vivo optogenetics, this work demonstrates that interglomerular circuitry produces potent inhibition of olfactory bulb output neurons via direct chemical and electrical synapses as well as by indirect pathways. The direct inhibitory synaptic input engages mitral cell intrinsic membrane properties to generate inhibition that outlasts the initial synaptic action.
Collapse
Affiliation(s)
- Shaolin Liu
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, Maryland 21042
| | - Adam C Puche
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, Maryland 21042
| | - Michael T Shipley
- Department of Anatomy and Neurobiology, Program in Neurosciences, University of Maryland School of Medicine, Baltimore, Maryland 21042
| |
Collapse
|
15
|
Yu Y, Burton SD, Tripathy SJ, Urban NN. Postnatal development attunes olfactory bulb mitral cells to high-frequency signaling. J Neurophysiol 2015; 114:2830-42. [PMID: 26354312 DOI: 10.1152/jn.00315.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 09/04/2015] [Indexed: 11/22/2022] Open
Abstract
Mitral cells (MCs) are a major class of principal neurons in the vertebrate olfactory bulb, conveying odor-evoked activity from the peripheral sensory neurons to olfactory cortex. Previous work has described the development of MC morphology and connectivity during the first few weeks of postnatal development. However, little is known about the postnatal development of MC intrinsic biophysical properties. To understand stimulus encoding in the developing olfactory bulb, we have therefore examined the development of MC intrinsic biophysical properties in acute slices from postnatal day (P)7-P35 mice. Across development, we observed systematic changes in passive membrane properties and action potential waveforms consistent with a developmental increase in sodium and potassium conductances. We further observed developmental decreases in hyperpolarization-evoked membrane potential sag and firing regularity, extending recent links between MC sag heterogeneity and firing patterns. We then applied a novel combination of statistical analyses to examine how the evolution of these intrinsic biophysical properties specifically influenced the representation of fluctuating stimuli by MCs. We found that immature MCs responded to frozen fluctuating stimuli with lower firing rates, lower spike-time reliability, and lower between-cell spike-time correlations than more mature MCs. Analysis of spike-triggered averages revealed that these changes in spike timing were driven by a developmental shift from broad integration of inputs to more selective detection of coincident inputs. Consistent with this shift, generalized linear model fits to MC firing responses demonstrated an enhanced encoding of high-frequency stimulus features by mature MCs.
Collapse
Affiliation(s)
- Yiyi Yu
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania; Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Shawn D Burton
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania; Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania; and
| | - Shreejoy J Tripathy
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Nathaniel N Urban
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania; Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania; and Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| |
Collapse
|