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Fei F, Wang X, Xu C, Shi J, Gong Y, Cheng H, Lai N, Ruan Y, Ding Y, Wang S, Chen Z, Wang Y. Discrete subicular circuits control generalization of hippocampal seizures. Nat Commun 2022; 13:5010. [PMID: 36008421 PMCID: PMC9411516 DOI: 10.1038/s41467-022-32742-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 08/15/2022] [Indexed: 11/09/2022] Open
Abstract
Epilepsy is considered a circuit-level dysfunction associated with imbalanced excitation-inhibition, it is therapeutically necessary to identify key brain regions and related circuits in epilepsy. The subiculum is an essential participant in epileptic seizures, but the circuit mechanism underlying its role remains largely elusive. Here we deconstruct the diversity of subicular circuits in a mouse model of epilepsy. We find that excitatory subicular pyramidal neurons heterogeneously control the generalization of hippocampal seizures by projecting to different downstream regions. Notably, anterior thalamus-projecting subicular neurons bidirectionally mediate seizures, while entorhinal cortex-projecting subicular neurons act oppositely in seizure modulation. These two subpopulations are structurally and functionally dissociable. An intrinsically enhanced hyperpolarization-activated current and robust bursting intensity in anterior thalamus-projecting neurons facilitate synaptic transmission, thus contributing to the generalization of hippocampal seizures. These results demonstrate that subicular circuits have diverse roles in epilepsy, suggesting the necessity to precisely target specific subicular circuits for effective treatment of epilepsy.
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Affiliation(s)
- Fan Fei
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xia Wang
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
| | - Jiaying Shi
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yiwei Gong
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Heming Cheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Nanxi Lai
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yeping Ruan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yao Ding
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shuang Wang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhong Chen
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China. .,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China. .,Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Yi Wang
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China. .,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China. .,Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
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Paknahad J, Humayun M, Lazzi G. Selective Activation of Retinal Ganglion Cell Subtypes Through Targeted Electrical Stimulation Parameters. IEEE Trans Neural Syst Rehabil Eng 2022; 30:350-359. [PMID: 35130164 PMCID: PMC8904155 DOI: 10.1109/tnsre.2022.3149967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To restore vision to the low vision, epiretinal implants have been developed to electrically stimulate the healthy retinal ganglion cells (RGCs) in the degenerate retina. Given the diversity of retinal ganglion cells as well as the difference in their visual function, selective activation of RGCs subtypes can significantly improve the quality of the restored vision. Our recent results demonstrated that with the proper modulation of the current amplitude, small D1-bistratified cells with the contribution to blue/yellow color opponent pathway can be selectively activated at high frequency (200 Hz). The computational results correlated with the clinical findings revealing the blue sensation of 5/7 subjects with epiretinal implants at high frequency. Here we further explored the impacts of alterations in pulse duration and interphase gap on the response of RGCs at high frequency. We used the developed RGCs, A2-monostratified and D1-bistratified, and examined their response to a range of pulse durations (0.1−1.2 ms) and interphase gaps (0−1 ms). We found that the use of short pulse durations with no interphase gap at high frequency increases the differential response of RGCs, offering better opportunities for selective activation of D1 cells. The presence of the interphase gap has shown to reduce the overall differential response of RGCs. We also explored how the low density of calcium channels enhances the responsiveness of RGCs at high frequency.
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Affiliation(s)
- Sodikdjon A. Kodirov
- Pavlov Institute of Physiology Russian Academy of Sciences Saint Petersburg Russia
- Institute of Physiology and Pathophysiology University Medical Center Mainz Mainz Germany
- Department of Biological Sciences University of Texas at Brownsville Brownsville TX USA
- Instituto de Medicina MolecularUniversidade de Lisboa Lisbon Portugal
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Vasnik S, Sikdar SK. Cholinergic receptor-independent modulation of intrinsic resonance in the rat subiculum neurons through inhibition of hyperpolarization-activated cyclic nucleotide-gated channels. Acta Physiol (Oxf) 2021; 231:e13603. [PMID: 33332740 DOI: 10.1111/apha.13603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/22/2020] [Accepted: 12/11/2020] [Indexed: 11/27/2022]
Abstract
AIM Acetylcholine release is vital in the pacing of theta rhythms in the hippocampus. The subiculum is the output region of the hippocampus with different neuronal subtypes that generate theta oscillations during arousal and rapid eye movement sleep. The combination of intrinsic resonance in the hippocampal neurons and the periodic excitation of hippocampal excitatory and inhibitory neurons by cholinergic pathway drives theta oscillations. However, the acetylcholine mediated effect on intrinsic subthreshold resonance generating hyperpolarization-activated cyclic nucleotide-gated current, Ih of subicular neurons is unexplored. We studied the acetylcholine receptor-independent effect of cholinergic agents on the intrinsic properties of subiculum principal neurons and the underlying mechanism. METHODS We bath perfused acetylcholine or nicotine on rat brain slices in the presence of synaptic blockers. The physiological effect was studied by cholinergic fibres stimulation and electrophysiological recordings under whole-cell mode of subiculum neurons using septohippocampal sections. RESULTS Exogenously applied acetylcholine in the presence of atropine affected two groups of subicular neurons differently. Acetylcholine reduced the resonance frequency and Ih in bursting neurons, whereas these properties were unaffected in regular firing neurons. Subsequently, the endogenously released acetylcholine by stimulation showed a selective suppressive effect on Ih , sag, and resonance in burst firing among the two excitatory neurons. Nicotine suppressed the Ih amplitude in burst firing neurons, which was evident by decreased sag amplitude and resonance frequency and increased excitability. CONCLUSION Our study suggests cell type-specific acetylcholine receptor-independent shift in resonance frequency by partially inhibiting HCN current during high cholinergic inputs.
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Affiliation(s)
- Sonali Vasnik
- Molecular Biophysics Unit Indian Institute of Science Bangalore India
| | - Sujit K. Sikdar
- Molecular Biophysics Unit Indian Institute of Science Bangalore India
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Paknahad J, Loizos K, Yue L, Humayun MS, Lazzi G. Color and cellular selectivity of retinal ganglion cell subtypes through frequency modulation of electrical stimulation. Sci Rep 2021; 11:5177. [PMID: 33664347 PMCID: PMC7933163 DOI: 10.1038/s41598-021-84437-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/15/2021] [Indexed: 01/31/2023] Open
Abstract
Epiretinal prostheses aim at electrically stimulating the inner most surviving retinal cells-retinal ganglion cells (RGCs)-to restore partial sight to the blind. Recent tests in patients with epiretinal implants have revealed that electrical stimulation of the retina results in the percept of color of the elicited phosphenes, which depends on the frequency of stimulation. This paper presents computational results that are predictive of this finding and further support our understanding of the mechanisms of color encoding in electrical stimulation of retina, which could prove pivotal for the design of advanced retinal prosthetics that elicit both percept and color. This provides, for the first time, a directly applicable "amplitude-frequency" stimulation strategy to "encode color" in future retinal prosthetics through a predictive computational tool to selectively target small bistratified cells, which have been shown to contribute to "blue-yellow" color opponency in the retinal circuitry. The presented results are validated with experimental data reported in the literature and correlated with findings in blind patients with a retinal prosthetic implant collected by our group.
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Affiliation(s)
- Javad Paknahad
- grid.42505.360000 0001 2156 6853Department of Electrical Engineering, University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853The Institute for Technology and Medical Systems (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA USA
| | - Kyle Loizos
- grid.42505.360000 0001 2156 6853The Institute for Technology and Medical Systems (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA USA
| | - Lan Yue
- grid.42505.360000 0001 2156 6853Roski Eye Institute, University of Southern California, Los Angeles, CA USA
| | - Mark S. Humayun
- grid.42505.360000 0001 2156 6853Roski Eye Institute, University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853Departments of Ophthalmology and Biomedical Engineering, University of Southern California, Los Angeles, CA USA
| | - Gianluca Lazzi
- grid.42505.360000 0001 2156 6853Department of Electrical Engineering, University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853The Institute for Technology and Medical Systems (ITEMS), Keck School of Medicine, University of Southern California, Los Angeles, CA USA ,grid.42505.360000 0001 2156 6853Departments of Ophthalmology and Biomedical Engineering, University of Southern California, Los Angeles, CA USA
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Paknahad J, Loizos K, Humayun M, Lazzi G. Targeted Stimulation of Retinal Ganglion Cells in Epiretinal Prostheses: A Multiscale Computational Study. IEEE Trans Neural Syst Rehabil Eng 2020; 28:2548-2556. [PMID: 32991284 PMCID: PMC7737501 DOI: 10.1109/tnsre.2020.3027560] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Retinal prostheses aim at restoring partial sight to patients that are blind due to retinal degenerative diseases by electrically stimulating the surviving healthy retinal neurons. Ideally, the electrical stimulation of the retina is intended to induce localized, focused, percepts only; however, some epiretinal implant subjects have reported seeing elongated phosphenes in a single electrode stimulation due to the axonal activation of retinal ganglion cells (RGCs). This issue can be addressed by properly devising stimulation waveforms so that the possibility of inducing axonal activation of RGCs is minimized. While strategies to devise electrical stimulation waveforms to achieve a focal RGCs response have been reported in literature, the underlying mechanisms are not well understood. This article intends to address this gap; we developed morphologically and biophysically realistic computational models of two classified RGCs: D1-bistratified and A2-monostratified. Computational results suggest that the sodium channel band (SOCB) is less sensitive to modulations in stimulation parameters than the distal axon (DA), and DA stimulus threshold is less sensitive to physiological differences among RGCs. Therefore, over a range of RGCs distal axon diameters, short-pulse symmetric biphasic waveforms can enhance the stimulation threshold difference between the SOCB and the DA. Appropriately designed waveforms can avoid axonal activation of RGCs, implying a consequential reduction of undesired strikes in the visual field.
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Paknahad J, Loizos K, Humayun M, Lazzi G. Responsiveness of Retinal Ganglion Cells Through Frequency Modulation of Electrical Stimulation: A Computational Modeling Study .. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:3393-3398. [PMID: 33018732 DOI: 10.1109/embc44109.2020.9176125] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Electrical stimulation of surviving retinal neurons has proven effective in restoring sight to totally blind patients affected by retinal degenerative diseases. Morphological and biophysical differences among retinal ganglion cells (RGCs) are important factors affecting their response to epiretinal electrical stimulation. Although detailed models of ON and OFF RGCs have already been investigated, here we developed morphologically and biophysically realistic computational models of two classified RGCs, D1-bistratified and A2-monostratified, and analyzed their response to alternations in stimulation frequency (up to 200 Hz). Results show that the D1-bistratified cell is more responsive to high frequency stimulation compared to the A2-monostratified cell. This differential RGCs response suggests a potential avenue for selective activation, and in turn different encoded percept of RGCs.
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Del Pino I, Tocco C, Magrinelli E, Marcantoni A, Ferraguto C, Tomagra G, Bertacchi M, Alfano C, Leinekugel X, Frick A, Studer M. COUP-TFI/Nr2f1 Orchestrates Intrinsic Neuronal Activity during Development of the Somatosensory Cortex. Cereb Cortex 2020; 30:5667-5685. [DOI: 10.1093/cercor/bhaa137] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/17/2020] [Accepted: 04/29/2020] [Indexed: 01/19/2023] Open
Abstract
Abstract
The formation of functional cortical maps in the cerebral cortex results from a timely regulated interaction between intrinsic genetic mechanisms and electrical activity. To understand how transcriptional regulation influences network activity and neuronal excitability within the neocortex, we used mice deficient for Nr2f1 (also known as COUP-TFI), a key determinant of primary somatosensory (S1) area specification during development. We found that the cortical loss of Nr2f1 impacts on spontaneous network activity and synchronization of S1 cortex at perinatal stages. In addition, we observed alterations in the intrinsic excitability and morphological features of layer V pyramidal neurons. Accordingly, we identified distinct voltage-gated ion channels regulated by Nr2f1 that might directly influence intrinsic bioelectrical properties during critical time windows of S1 cortex specification. Altogether, our data suggest a tight link between Nr2f1 and neuronal excitability in the developmental sequence that ultimately sculpts the emergence of cortical network activity within the immature neocortex.
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Affiliation(s)
- Isabel Del Pino
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
- Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain
| | - Chiara Tocco
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
| | - Elia Magrinelli
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
- Département des Neurosciences Fondamentales, Université de Lausanne, CH-1005 Lausanne, Switzerland
| | - Andrea Marcantoni
- Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, 10125 Torino, Italy
| | | | - Giulia Tomagra
- Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, 10125 Torino, Italy
| | | | | | - Xavier Leinekugel
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Andreas Frick
- Université de Bordeaux, Inserm U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Michèle Studer
- Université Côte d’Azur, CNRS, Inserm, iBV, 06108 Nice, France
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Schulze F, Müller S, Guli X, Schumann L, Brehme H, Riffert T, Rohde M, Goerss D, Rackow S, Einsle A, Kirschstein T, Köhling R. CK2 Inhibition Prior to Status Epilepticus Persistently Enhances K Ca2 Function in CA1 Which Slows Down Disease Progression. Front Cell Neurosci 2020; 14:33. [PMID: 32174814 PMCID: PMC7054465 DOI: 10.3389/fncel.2020.00033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/04/2020] [Indexed: 12/19/2022] Open
Abstract
Purpose Epilepsy therapy is currently based on anti-seizure drugs that do not modify the course of the disease, i.e., they are not anti-epileptogenic in nature. Previously, we observed that in vivo casein kinase 2 (CK2) inhibition with 4,5,6,7-tetrabromotriazole (TBB) had anti-epileptogenic effects in the acute epilepsy slice model. Methods Here, we pretreated rats with TBB in vivo prior to the establishment of a pilocarpine-induced status epilepticus (SE) in order to analyze the long-term sequelae of such a preventive TBB administration. Results We found that TBB pretreatment delayed onset of seizures after pilocarpine and slowed down disease progression during epileptogenesis. This was accompanied with a reduced proportion of burst firing neurons in the CA1 area. Western blot analyses demonstrated that CA1 tissue from TBB-pretreated epileptic animals contained significantly less CK2 than TBB-pretreated controls. On the transcriptional level, TBB pretreatment led to differential gene expression changes of KCa2.2, but also of HCN1 and HCN3 channels. Thus, in the presence of the HCN channel blocker ZD7288, pretreatment with TBB rescued the afterhyperpolarizing potential (AHP) as well as spike frequency adaptation in epileptic animals, both of which are prominent functions of KCa2 channels. Conclusion These data indicate that TBB pretreatment prior to SE slows down disease progression during epileptogenesis involving increased KCa2 function, probably due to a persistently decreased CK2 protein expression.
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Affiliation(s)
- Felix Schulze
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Steffen Müller
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Xiati Guli
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Lukas Schumann
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Hannes Brehme
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Till Riffert
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Marco Rohde
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Doreen Goerss
- Department of Psychosomatic Medicine, Rostock University Medical Center, Rostock, Germany.,German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Simone Rackow
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Anne Einsle
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany
| | - Timo Kirschstein
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany.,Center of Transdisciplinary Neurosciences Rostock, University of Rostock, Rostock, Germany
| | - Rüdiger Köhling
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock, Germany.,Center of Transdisciplinary Neurosciences Rostock, University of Rostock, Rostock, Germany
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Angulo SL, Henzi T, Neymotin SA, Suarez MD, Lytton WW, Schwaller B, Moreno H. Amyloid pathology-produced unexpected modifications of calcium homeostasis in hippocampal subicular dendrites. Alzheimers Dement 2020; 16:251-261. [PMID: 31668966 DOI: 10.1016/j.jalz.2019.07.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Alzheimer's disease (AD) is linked to neuronal calcium dyshomeostasis, which is associated with network hyperexcitability. Decreased expression of the calcium-binding protein cal- bindin-D28K (CB) might be a susceptibility factor for AD. The subiculum is affected early in AD, for unknown reasons. METHODS In AD, CB knock-out and control mice fluorescence Ca2+ imaging combined with patch clamp were used to characterize Ca2+ dynamics, resting Ca2+ , and Ca2+ -buffering capacity in subicular neurons. CB expression levels in wild-type and AD mice were also analyzed. RESULTS The subiculum and dentate gyrus of wild-type mice showed age-related decline in CB expression not observed in AD mice. Resting Ca2+ and Ca2+ -buffering capacity was increased in aged AD mice subicular dendrites. Modeling suggests that AD calcium changes can be explained by alterations of Ca2+ extrusion pumps rather than by buffers. DISCUSSION Overall, abnormal Ca2+ homeostasis in AD has an age dependency that comprises multiple mechanisms, including compensatory processes.
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Affiliation(s)
- Sergio L Angulo
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Thomas Henzi
- Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Samuel A Neymotin
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Manuel D Suarez
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - William W Lytton
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY, USA
- Kings County Hospital, Brooklyn, NY, USA
| | - Beat Schwaller
- Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Herman Moreno
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY, USA
- Kings County Hospital, Brooklyn, NY, USA
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Labarrera C, Deitcher Y, Dudai A, Weiner B, Kaduri Amichai A, Zylbermann N, London M. Adrenergic Modulation Regulates the Dendritic Excitability of Layer 5 Pyramidal Neurons In Vivo. Cell Rep 2019; 23:1034-1044. [PMID: 29694883 DOI: 10.1016/j.celrep.2018.03.103] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 01/22/2018] [Accepted: 03/19/2018] [Indexed: 02/01/2023] Open
Abstract
The excitability of the apical tuft of layer 5 pyramidal neurons is thought to play a crucial role in behavioral performance and synaptic plasticity. We show that the excitability of the apical tuft is sensitive to adrenergic neuromodulation. Using two-photon dendritic Ca2+ imaging and in vivo whole-cell and extracellular recordings in awake mice, we show that application of the α2A-adrenoceptor agonist guanfacine increases the probability of dendritic Ca2+ events in the tuft and lowers the threshold for dendritic Ca2+ spikes. We further show that these effects are likely to be mediated by the dendritic current Ih. Modulation of Ih in a realistic compartmental model controlled both the generation and magnitude of dendritic calcium spikes in the apical tuft. These findings suggest that adrenergic neuromodulation may affect cognitive processes such as sensory integration, attention, and working memory by regulating the sensitivity of layer 5 pyramidal neurons to top-down inputs.
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Affiliation(s)
- Christina Labarrera
- Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yair Deitcher
- Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Amir Dudai
- Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Benjamin Weiner
- Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Adi Kaduri Amichai
- Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Neta Zylbermann
- Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Michael London
- Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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Hashiguchi S, Doi H, Kunii M, Nakamura Y, Shimuta M, Suzuki E, Koyano S, Okubo M, Kishida H, Shiina M, Ogata K, Hirashima F, Inoue Y, Kubota S, Hayashi N, Nakamura H, Takahashi K, Katsumoto A, Tada M, Tanaka K, Sasaoka T, Miyatake S, Miyake N, Saitsu H, Sato N, Ozaki K, Ohta K, Yokota T, Mizusawa H, Mitsui J, Ishiura H, Yoshimura J, Morishita S, Tsuji S, Takeuchi H, Ishikawa K, Matsumoto N, Ishikawa T, Tanaka F. Ataxic phenotype with altered Ca V3.1 channel property in a mouse model for spinocerebellar ataxia 42. Neurobiol Dis 2019; 130:104516. [PMID: 31229688 DOI: 10.1016/j.nbd.2019.104516] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 06/06/2019] [Accepted: 06/19/2019] [Indexed: 11/16/2022] Open
Abstract
Spinocerebellar ataxia 42 (SCA42) is a neurodegenerative disorder recently shown to be caused by c.5144G > A (p.Arg1715His) mutation in CACNA1G, which encodes the T-type voltage-gated calcium channel CaV3.1. Here, we describe a large Japanese family with SCA42. Postmortem pathological examination revealed severe cerebellar degeneration with prominent Purkinje cell loss without ubiquitin accumulation in an SCA42 patient. To determine whether this mutation causes ataxic symptoms and neurodegeneration, we generated knock-in mice harboring c.5168G > A (p.Arg1723His) mutation in Cacna1g, corresponding to the mutation identified in the SCA42 family. Both heterozygous and homozygous mutants developed an ataxic phenotype from the age of 11-20 weeks and showed Purkinje cell loss at 50 weeks old. Degenerative change of Purkinje cells and atrophic thinning of the molecular layer were conspicuous in homozygous knock-in mice. Electrophysiological analysis of Purkinje cells using acute cerebellar slices from young mice showed that the point mutation altered the voltage dependence of CaV3.1 channel activation and reduced the rebound action potentials after hyperpolarization, although it did not significantly affect the basic properties of synaptic transmission onto Purkinje cells. Finally, we revealed that the resonance of membrane potential of neurons in the inferior olivary nucleus was decreased in knock-in mice, which indicates that p.Arg1723His CaV3.1 mutation affects climbing fiber signaling to Purkinje cells. Altogether, our study shows not only that a point mutation in CACNA1G causes an ataxic phenotype and Purkinje cell degeneration in a mouse model, but also that the electrophysiological abnormalities at an early stage of SCA42 precede Purkinje cell loss.
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Affiliation(s)
- Shunta Hashiguchi
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Hiroshi Doi
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Misako Kunii
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Yukihiro Nakamura
- Department of Pharmacology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Misa Shimuta
- Department of Pharmacology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Etsuko Suzuki
- Department of Pharmacology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Shigeru Koyano
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Masaki Okubo
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Hitaru Kishida
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Masaaki Shiina
- Department of Biochemistry, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kazuhiro Ogata
- Department of Biochemistry, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Fumiko Hirashima
- Department of Rehabilitation Medicine, Flower and Forest Tokyo Hospital, 2-3-6 Nishigahara, Kita-ku, Tokyo 114-0024, Japan
| | - Yukichi Inoue
- Department of Neurology, Toyama Prefectural Rehabilitation Hospital and Support Center for Children with Disabilities, 36 Shimoiino, Toyama 931-8517, Japan
| | - Shun Kubota
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Noriko Hayashi
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Haruko Nakamura
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Keita Takahashi
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Atsuko Katsumoto
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Mikiko Tada
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kenichi Tanaka
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Toshikuni Sasaoka
- Department of Comparative and Experimental Medicine, Center for Bioresource-based Researches, Brain Research Institute, Niigata University, 1-757 Asahimachidori, Chuo-ku, Niigata 951-8585, Japan
| | - Satoko Miyatake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Hirotomo Saitsu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Nozomu Sato
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Kokoro Ozaki
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Kiyobumi Ohta
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Takanori Yokota
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Hidehiro Mizusawa
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Jun Mitsui
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Jun Yoshimura
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Shinichi Morishita
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Hideyuki Takeuchi
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Kinya Ishikawa
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Taro Ishikawa
- Department of Pharmacology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
| | - Fumiaki Tanaka
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
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13
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Diverse synaptic and dendritic mechanisms of complex spike burst generation in hippocampal CA3 pyramidal cells. Nat Commun 2019; 10:1859. [PMID: 31015414 PMCID: PMC6478939 DOI: 10.1038/s41467-019-09767-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 03/27/2019] [Indexed: 01/21/2023] Open
Abstract
Complex spike bursts (CSBs) represent a characteristic firing pattern of hippocampal pyramidal cells (PCs). In CA1PCs, CSBs are driven by regenerative dendritic plateau potentials, produced by correlated entorhinal cortical and CA3 inputs that simultaneously depolarize distal and proximal dendritic domains. However, in CA3PCs neither the generation mechanisms nor the computational role of CSBs are well elucidated. We show that CSBs are induced by dendritic Ca2+ spikes in CA3PCs. Surprisingly, the ability of CA3PCs to produce CSBs is heterogeneous, with non-uniform synaptic input-output transformation rules triggering CSBs. The heterogeneity is partly related to the topographic position of CA3PCs; we identify two ion channel types, HCN and Kv2 channels, whose proximodistal activity gradients contribute to subregion-specific modulation of CSB propensity. Our results suggest that heterogeneous dendritic integrative properties, along with previously reported synaptic connectivity gradients, define functional subpopulations of CA3PCs that may support CA3 network computations underlying associative memory processes.
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14
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Lehnhoff J, Strauss U, Wierschke S, Grosser S, Pollali E, Schneider UC, Holtkamp M, Dehnicke C, Deisz RA. The anticonvulsant lamotrigine enhances Ih in layer 2/3 neocortical pyramidal neurons of patients with pharmacoresistant epilepsy. Neuropharmacology 2019; 144:58-69. [DOI: 10.1016/j.neuropharm.2018.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 09/19/2018] [Accepted: 10/05/2018] [Indexed: 11/29/2022]
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15
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Kameneva T, Meffin H, Burkitt AN, Grayden DB. Bistability in Hodgkin-Huxley-type equations. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:4728-4731. [PMID: 30441405 DOI: 10.1109/embc.2018.8513233] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We study how initial conditions of the Hodgkin-Huxley model affect the dynamics of simulated neurons. We systematically vary the amplitudes of depolarization currents in order to bring neuron dynamics to stable equilibrium. Our results demonstrate that simulated neurons can have spontaneous spiking or a silent state, depending on the initial conditions. We propose the methodology to study the circumstances under which Purkinje cells transit between hyperpolarized quiescent state (down state) and a depolarized spiking state (up state). We show that results derived using the Hodgkin-Huxley methodology should be carefully analyzed before suggesting a direct relevance to neuroprosthetic implants.
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16
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Qin W, Hadjinicolaou A, Grayden DB, Meffin H, Burkitt AN, Ibbotson MR, Kameneva T. Single-compartment models of retinal ganglion cells with different electrophysiologies. NETWORK (BRISTOL, ENGLAND) 2017; 28:74-93. [PMID: 29649919 DOI: 10.1080/0954898x.2018.1455993] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
There are more than 15 different types of retinal ganglion cells (RGCs) in the mammalian retina. To model responses of RGCs to electrical stimulation, we use single-compartment Hodgkin-Huxley-type models and run simulations in the Neuron environment. We use our recently published in vitro data of different morphological cell types to constrain the model, and study the effects of electrophysiology on the cell responses separately from the effects of morphology. We find simple models that can match the spike patterns of different types of RGCs. These models, with different input-output properties, may be used in a network to study retinal network dynamics and interactions.
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Affiliation(s)
- Wei Qin
- a Department of Biomedical Engineering , The University of Melbourne , Melbourne , Australia
| | - Alex Hadjinicolaou
- b Department of Neurology, Massachusetts General Hospital , Harvard Medical School , Boston , USA
| | - David B Grayden
- a Department of Biomedical Engineering , The University of Melbourne , Melbourne , Australia
| | - Hamish Meffin
- c National Vision Research Institute , Australian College of Optometry , Melbourne , Australia
- d Department of Optometry and Vision Sciences , University of Melbourne , Melbourne , Australia
| | - Anthony N Burkitt
- a Department of Biomedical Engineering , The University of Melbourne , Melbourne , Australia
| | - Michael R Ibbotson
- c National Vision Research Institute , Australian College of Optometry , Melbourne , Australia
- d Department of Optometry and Vision Sciences , University of Melbourne , Melbourne , Australia
| | - Tatiana Kameneva
- a Department of Biomedical Engineering , The University of Melbourne , Melbourne , Australia
- e Engineering and Technology , Swinburne University of Technology , Melbourne , Australia
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17
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Kameneva T, Maturana MI, Hadjinicolaou AE, Cloherty SL, Ibbotson MR, Grayden DB, Burkitt AN, Meffin H. Retinal ganglion cells: mechanisms underlying depolarization block and differential responses to high frequency electrical stimulation of ON and OFF cells. J Neural Eng 2016; 13:016017. [DOI: 10.1088/1741-2560/13/1/016017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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18
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Huang S, Hong S, De Schutter E. Non-linear leak currents affect mammalian neuron physiology. Front Cell Neurosci 2015; 9:432. [PMID: 26594148 PMCID: PMC4635211 DOI: 10.3389/fncel.2015.00432] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 10/14/2015] [Indexed: 01/24/2023] Open
Abstract
In their seminal works on squid giant axons, Hodgkin, and Huxley approximated the membrane leak current as Ohmic, i.e., linear, since in their preparation, sub-threshold current rectification due to the influence of ionic concentration is negligible. Most studies on mammalian neurons have made the same, largely untested, assumption. Here we show that the membrane time constant and input resistance of mammalian neurons (when other major voltage-sensitive and ligand-gated ionic currents are discounted) varies non-linearly with membrane voltage, following the prediction of a Goldman-Hodgkin-Katz-based passive membrane model. The model predicts that under such conditions, the time constant/input resistance-voltage relationship will linearize if the concentration differences across the cell membrane are reduced. These properties were observed in patch-clamp recordings of cerebellar Purkinje neurons (in the presence of pharmacological blockers of other background ionic currents) and were more prominent in the sub-threshold region of the membrane potential. Model simulations showed that the non-linear leak affects voltage-clamp recordings and reduces temporal summation of excitatory synaptic input. Together, our results demonstrate the importance of trans-membrane ionic concentration in defining the functional properties of the passive membrane in mammalian neurons as well as other excitable cells.
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Affiliation(s)
- Shiwei Huang
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University Okinawa, Japan
| | - Sungho Hong
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University Okinawa, Japan
| | - Erik De Schutter
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University Okinawa, Japan
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19
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Gasselin C, Inglebert Y, Debanne D. Homeostatic regulation of h-conductance controls intrinsic excitability and stabilizes the threshold for synaptic modification in CA1 neurons. J Physiol 2015; 593:4855-69. [PMID: 26316265 DOI: 10.1113/jp271369] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 08/15/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We determined the contribution of the hyperpolarization-activated cationic (h) current (Ih ) to the homeostatic regulation of CA1 pyramidal cells in vitro using chronic treatments (48 h) that either increase (picrotoxin) or decrease (kynurenate) neuronal activity. The h-conductance was found to be up- or down-regulated following chronic activity enhancement or activity deprivation, respectively. This bidirectional plasticity of Ih was found to subsequently alter both apparent input resistance and intrinsic neuronal excitability. Bidirectional homeostatic plasticity of Ih also determined EPSP waveform and EPSP summation tested at 5-30 Hz. Long-term synaptic modification induced by repetitive stimulation of the Schaffer collaterals was found to be constant across treatments in the presence of Ih but not when Ih was blocked pharmacologically. Thus, bidirectional homeostatic regulation of Ih stabilizes induction of long-term synaptic modification in CA1 pyramidal neurons that depends on EPSP summation. ABSTRACT The hyperpolarization-activated cationic (h) current is a voltage-shock absorber, highly expressed in the dendrites of CA1 pyramidal neurons. Up-regulation of Ih has been reported following episodes of intense network activity but the effect of activity deprivation on Ih and the functional consequence of homeostatic regulation of Ih remain unclear. We determined here the contribution of Ih to the homeostatic regulation of CA1 pyramidal cell excitability. Intrinsic neuronal excitability was decreased in neurons treated for 2-3 days with the GABAA channel blocker picrotoxin (PiTx) but increased in neurons treated (2-3 days) with the glutamate receptor antagonist kynurenate (Kyn). Membrane capacitance remained unchanged after treatment but the apparent input resistance was reduced for PiTx-treated neurons and enhanced for Kyn-treated neurons. Maximal Ih conductance was up-regulated after chronic hyperactivity but down-regulated following chronic hypoactivity. Up-regulation of Ih in PiTx-treated cultures was found to accelerate EPSP kinetics and reduce temporal summation of EPSPs whereas opposite effects were observed in Kyn-treated cultures, indicating that homeostatic regulation of Ih may control the induction of synaptic modification depending on EPSP summation. In fact, stimulation of the Schaffer collaterals at 3-10 Hz induced differential levels of plasticity in PiTx-treated and Kyn-treated neurons when Ih was blocked pharmacologically but not in control conditions. These data indicate that homeostatic regulation of Ih normalizes the threshold for long-term synaptic modification that depends on EPSP summation. In conclusion, bidirectional homeostatic regulation of Ih not only controls spiking activity but also stabilizes the threshold for long-term potentiation induced in CA1 pyramidal neurons by repetitive stimulation.
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Affiliation(s)
- Célia Gasselin
- INSERM, U-1072, Marseille, France.,Aix-Marseille University, Marseille, France.,Neurobiology of ion channels (UNIS), Marseille, France
| | - Yanis Inglebert
- INSERM, U-1072, Marseille, France.,Aix-Marseille University, Marseille, France.,Neurobiology of ion channels (UNIS), Marseille, France
| | - Dominique Debanne
- INSERM, U-1072, Marseille, France.,Aix-Marseille University, Marseille, France.,Neurobiology of ion channels (UNIS), Marseille, France
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20
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Yamada-Hanff J, Bean BP. Activation of Ih and TTX-sensitive sodium current at subthreshold voltages during CA1 pyramidal neuron firing. J Neurophysiol 2015; 114:2376-89. [PMID: 26289465 PMCID: PMC4620139 DOI: 10.1152/jn.00489.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/13/2015] [Indexed: 11/22/2022] Open
Abstract
We used dynamic clamp and action potential clamp techniques to explore how currents carried by tetrodotoxin-sensitive sodium channels and HCN channels (Ih) regulate the behavior of CA1 pyramidal neurons at resting and subthreshold voltages. Recording from rat CA1 pyramidal neurons in hippocampal slices, we found that the apparent input resistance and membrane time constant were strongly affected by both conductances, with Ih acting to decrease apparent input resistance and time constant and sodium current acting to increase both. We found that both Ih and sodium current were active during subthreshold summation of artificial excitatory postsynaptic potentials (EPSPs) generated by dynamic clamp, with Ih dominating at less depolarized voltages and sodium current at more depolarized voltages. Subthreshold sodium current-which amplifies EPSPs-was most effectively recruited by rapid voltage changes, while Ih-which blunts EPSPs-was maximal for slow voltage changes. The combined effect is to selectively amplify rapid EPSPs. We did similar experiments in mouse CA1 pyramidal neurons, doing voltage-clamp experiments using experimental records of action potential firing of CA1 neurons previously recorded in awake, behaving animals as command voltages to quantify flow of Ih and sodium current at subthreshold voltages. Subthreshold sodium current was larger and subthreshold Ih was smaller in mouse neurons than in rat neurons. Overall, the results show opposing effects of subthreshold sodium current and Ih in regulating subthreshold behavior of CA1 neurons, with subthreshold sodium current prominent in both rat and mouse CA1 pyramidal neurons and additional regulation by Ih in rat neurons.
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Affiliation(s)
- Jason Yamada-Hanff
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
| | - Bruce P Bean
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
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21
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Anderson GR, Aoto J, Tabuchi K, Földy C, Covy J, Yee AX, Wu D, Lee SJ, Chen L, Malenka RC, Südhof TC. β-Neurexins Control Neural Circuits by Regulating Synaptic Endocannabinoid Signaling. Cell 2015. [PMID: 26213384 DOI: 10.1016/j.cell.2015.06.056] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
α- and β-neurexins are presynaptic cell-adhesion molecules implicated in autism and schizophrenia. We find that, although β-neurexins are expressed at much lower levels than α-neurexins, conditional knockout of β-neurexins with continued expression of α-neurexins dramatically decreased neurotransmitter release at excitatory synapses in cultured cortical neurons. The β-neurexin knockout phenotype was attenuated by CB1-receptor inhibition, which blocks presynaptic endocannabinoid signaling, or by 2-arachidonoylglycerol synthesis inhibition, which impairs postsynaptic endocannabinoid release. In synapses formed by CA1-region pyramidal neurons onto burst-firing subiculum neurons, presynaptic in vivo knockout of β-neurexins aggravated endocannabinoid-mediated inhibition of synaptic transmission and blocked LTP; presynaptic CB1-receptor antagonists or postsynaptic 2-arachidonoylglycerol synthesis inhibition again reversed this block. Moreover, conditional knockout of β-neurexins in CA1-region neurons impaired contextual fear memories. Thus, our data suggest that presynaptic β-neurexins control synaptic strength in excitatory synapses by regulating postsynaptic 2-arachidonoylglycerol synthesis, revealing an unexpected role for β-neurexins in the endocannabinoid-dependent regulation of neural circuits.
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Affiliation(s)
- Garret R Anderson
- Department of Molecular and Cellular Physiology, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA; Department of Psychiatry and Behavioral Sciences, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Jason Aoto
- Department of Molecular and Cellular Physiology, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Katsuhiko Tabuchi
- Department of Molecular and Cellular Physiology, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA; Department of Neurophysiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
| | - Csaba Földy
- Department of Molecular and Cellular Physiology, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA; Department of Psychiatry and Behavioral Sciences, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Jason Covy
- Department of Molecular and Cellular Physiology, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Ada Xin Yee
- Department of Neurosurgery, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Dick Wu
- Department of Molecular and Cellular Physiology, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA; Department of Psychiatry and Behavioral Sciences, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Sung-Jin Lee
- Department of Molecular and Cellular Physiology, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Lu Chen
- Department of Neurosurgery, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Robert C Malenka
- Department of Psychiatry and Behavioral Sciences, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA; Nancy Pritzker Laboratory, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA; Howard Hughes Medical Institute, Stanford University Medical School, 265 Campus Drive, Stanford, CA 94305-5453, USA.
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22
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Eller J, Zarnadze S, Bäuerle P, Dugladze T, Gloveli T. Cell type-specific separation of subicular principal neurons during network activities. PLoS One 2015; 10:e0123636. [PMID: 25874555 PMCID: PMC4396839 DOI: 10.1371/journal.pone.0123636] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/23/2015] [Indexed: 11/18/2022] Open
Abstract
The hippocampal output structure, the subiculum, expresses two major memory relevant network rhythms, sharp wave ripple and gamma frequency oscillations. To this date, it remains unclear how the two distinct types of subicular principal cells, intrinsically bursting and regular spiking neurons, participate in these two network rhythms. Using concomitant local field potential and intracellular recordings in an in vitro mouse model that allows the investigation of both network rhythms, we found a cell type-specific segregation of principal neurons into participating intrinsically bursting and non-participating regular spiking cells. However, if regular spiking cells were kept at a more depolarized level, they did participate in a specific manner, suggesting a potential bimodal working model dependent on the level of excitation. Furthermore, intrinsically bursting and regular spiking cells exhibited divergent intrinsic membrane and synaptic properties in the active network. Thus, our results suggest a cell-type-specific segregation of principal cells into two separate groups during network activities, supporting the idea of two parallel streams of information processing within the subiculum.
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Affiliation(s)
- Joanna Eller
- Cellular and Network Physiology Group, Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Shota Zarnadze
- Cellular and Network Physiology Group, Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Peter Bäuerle
- Cellular and Network Physiology Group, Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Tamar Dugladze
- Cellular and Network Physiology Group, Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Cluster of excellence “NeuroCure”, Berlin, Germany
| | - Tengis Gloveli
- Cellular and Network Physiology Group, Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- * E-mail:
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23
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Kameneva T, Grayden DB, Meffin H, Burkitt AN. Feedback stimulation strategy: control of retinal ganglion cells activation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:1703-6. [PMID: 25570303 DOI: 10.1109/embc.2014.6943935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
It is possible to cause a sensation of light in patients who have lost photoreceptors due to degenerative eye diseases by targeting surviving neurons with electrical stimulation by means of visual prosthetic devices. All stimulation strategies in currently used visual prostheses are open-loop, that is, the stimulation parameters do not depend on the level of activation of neurons surrounding stimulating electrodes. In this paper, we investigate a closed-loop stimulation strategy using computer simulations of previously constrained models of ON and OFF retinal ganglion cells. Using a proportional-integral-type controller we show that it is possible to control activation level of both types of retinal ganglion cells. We also demonstrate that the controller tuned for a particular combination of synaptic currents continues to work during retina degeneration when excitatory currents are reduced by 20%.
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24
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Shah MM. Cortical HCN channels: function, trafficking and plasticity. J Physiol 2014; 592:2711-9. [PMID: 24756635 PMCID: PMC4104471 DOI: 10.1113/jphysiol.2013.270058] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 04/15/2014] [Indexed: 12/26/2022] Open
Abstract
The hyperpolarization-activated cyclic nucleotide-gated (HCN) channels belong to the superfamily of voltage-gated potassium ion channels. They are, however, activated by hyperpolarizing potentials and are permeable to cations. Four HCN subunits have been cloned, of which HCN1 and HCN2 subunits are predominantly expressed in the cortex. These subunits are principally located in pyramidal cell dendrites, although they are also found at lower concentrations in the somata of pyramidal neurons as well as other neuron subtypes. HCN channels are actively trafficked to dendrites by binding to the chaperone protein TRIP8b. Somato-dendritic HCN channels in pyramidal neurons modulate spike firing and synaptic potential integration by influencing the membrane resistance and resting membrane potential. Intriguingly, HCN channels are present in certain cortical axons and synaptic terminals too. Here, they regulate synaptic transmission but the underlying mechanisms appear to vary considerably amongst different synaptic terminals. In conclusion, HCN channels are expressed in multiple neuronal subcellular compartments in the cortex, where they have a diverse and complex effect on neuronal excitability.
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Affiliation(s)
- Mala M Shah
- Department of Pharmacology, UCL School of Pharmacy, London, UK
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25
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Pandey A, Sikdar SK. Depression biased non-Hebbian spike-timing-dependent synaptic plasticity in the rat subiculum. J Physiol 2014; 592:3537-57. [PMID: 24907304 DOI: 10.1113/jphysiol.2014.273367] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The subiculum is a structure that forms a bridge between the hippocampus and the entorhinal cortex (EC), and plays a major role in the memory consolidation process. Here, we demonstrate spike-timing-dependent plasticity (STDP) at the proximal excitatory inputs on the subicular pyramidal neurons of juvenile rat. Causal (positive) pairing of a single EPSP with a single back-propagating action potential (bAP) after a time interval of 10 ms (+10 ms) failed to induce plasticity. However, increasing the number of bAPs in a burst to three, at two different frequencies of 50 Hz (bAP burst) and 150 Hz, induced long-term depression (LTD) after a time interval of +10 ms in both the regular-firing (RF), and the weak burst firing (WBF) neurons. The LTD amplitude decreased with increasing time interval between the EPSP and the bAP burst. Reversing the order of the pairing of the EPSP and the bAP burst induced LTP at a time interval of -10 ms. This finding is in contrast with reports at other synapses, wherein pre- before postsynaptic (causal) pairing induced LTP and vice versa. Our results reaffirm the earlier observations that the relative timing of the pre- and postsynaptic activities can lead to multiple types of plasticity profiles. The induction of timing-dependent LTD (t-LTD) was dependent on postsynaptic calcium change via NMDA receptors in the WBF neurons, while it was independent of postsynaptic calcium change, but required active L-type calcium channels in the RF neurons. Thus the mechanism of synaptic plasticity may vary within a hippocampal subfield depending on the postsynaptic neuron involved. This study also reports a novel mechanism of LTD induction, where L-type calcium channels are involved in a presynaptically induced synaptic plasticity. The findings may have strong implications in the memory consolidation process owing to the central role of the subiculum and LTD in this process.
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Affiliation(s)
- Anurag Pandey
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560 012, India
| | - Sujit Kumar Sikdar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560 012, India
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26
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Sah N, Sikdar SK. Tonic current through GABAA receptors and hyperpolarization-activated cyclic nucleotide-gated channels modulate resonance properties of rat subicular pyramidal neurons. Eur J Neurosci 2014; 40:2241-54. [PMID: 24720274 DOI: 10.1111/ejn.12581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 02/10/2014] [Accepted: 03/05/2014] [Indexed: 11/26/2022]
Abstract
The subiculum, considered to be the output structure of the hippocampus, modulates information flow from the hippocampus to various cortical and sub-cortical areas such as the nucleus accumbens, lateral septal region, thalamus, nucleus gelatinosus, medial nucleus and mammillary nuclei. Tonic inhibitory current plays an important role in neuronal physiology and pathophysiology by modulating the electrophysiological properties of neurons. While the alterations of various electrical properties due to tonic inhibition have been studied in neurons from different regions, its influence on intrinsic subthreshold resonance in pyramidal excitatory neurons expressing hyperpolarization-activated cyclic nucleotide-gated (HCN) channels is not known. Using pharmacological agents, we show the involvement of α5βγ GABAA receptors in the picrotoxin-sensitive tonic current in subicular pyramidal neurons. We further investigated the contribution of tonic conductance in regulating subthreshold electrophysiological properties using current clamp and dynamic clamp experiments. We demonstrate that tonic GABAergic inhibition can actively modulate subthreshold properties, including resonance due to HCN channels, which can potentially alter the response dynamics of subicular pyramidal neurons in an oscillating neuronal network.
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Affiliation(s)
- Nirnath Sah
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560 012, India
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27
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Maturana MI, Grayden DB, Burkitt AN, Meffin H, Kameneva T. Multicompartment retinal ganglion cells response to high frequency bi-phasic pulse train stimulation: Simulation results. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2013:69-72. [PMID: 24109626 DOI: 10.1109/embc.2013.6609439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Retinal ganglion cells (RGCs) are the sole output neurons of the retina that carry information about a visual scene to the brain. By stimulating RGCs with electrical stimulation, it is possible to elicit a sensation of light for people with macular degeneration or retinitis pigmentosa. To investigate the responses of RGCs to high frequency bi-phasic pulse train stimulation, we use previously constrained models of multi-compartment OFF RGCs. The morphologies of mouse RGCs are taken from the Chalupa set of the NeuroMorpho database. The cell models are divided into compartments representing the dendrites, soma and axon that vary between the cells. A total of 132 cells are simulated in the NEURON environment. Results show that the cell morphology plays an important role in the response characteristics of the cell to high frequency bi-phasic pulse train stimulation.
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28
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Savage CO, Kameneva T, Grayden DB, Meffin H, Burkitt AN. Minimisation of required charge for desired neuronal spike rate. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2012:3009-12. [PMID: 23366558 DOI: 10.1109/embc.2012.6346597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Retinal implants restore limited visual perception to blind implantees by electrical stimulation of surviving neurons. We consider the efficacy of two electrical stimulation parameters, frequency of stimulation and interphase gap between cathodic and anodic phases, on the required charge to reach a desired neuronal spike rate. Using a Hodgkin-Huxley model of a neuron, we find the most efficient means of achieving a desired spike rate for neurons by electrical stimulation is to use a stimulation frequency identical to the desired spike rate, as well as a long interphase gap.
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Affiliation(s)
- Craig O Savage
- NeuroEngineering Laboratory, Department of Electrical and Electronic Engineering, The University of Melbourne, VIC 3010 Australia.
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29
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Maturana MI, Kameneva T, Burkitt AN, Meffin H, Grayden DB. The effect of morphology upon electrophysiological responses of retinal ganglion cells: simulation results. J Comput Neurosci 2013; 36:157-75. [PMID: 23835760 PMCID: PMC3950609 DOI: 10.1007/s10827-013-0463-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 04/15/2013] [Accepted: 05/14/2013] [Indexed: 11/30/2022]
Abstract
Retinal ganglion cells (RGCs) display differences in their morphology and intrinsic electrophysiology. The goal of this study is to characterize the ionic currents that explain the behavior of ON and OFF RGCs and to explore if all morphological types of RGCs exhibit the phenomena described in electrophysiological data. We extend our previous single compartment cell models of ON and OFF RGCs to more biophysically realistic multicompartment cell models and investigate the effect of cell morphology on intrinsic electrophysiological properties. The membrane dynamics are described using the Hodgkin - Huxley type formalism. A subset of published patch-clamp data from isolated intact mouse retina is used to constrain the model and another subset is used to validate the model. Two hundred morphologically distinct ON and OFF RGCs are simulated with various densities of ionic currents in different morphological neuron compartments. Our model predicts that the differences between ON and OFF cells are explained by the presence of the low voltage activated calcium current in OFF cells and absence of such in ON cells. Our study shows through simulation that particular morphological types of RGCs are capable of exhibiting the full range of phenomena described in recent experiments. Comparisons of outputs from different cells indicate that the RGC morphologies that best describe recent experimental results are ones that have a larger ratio of soma to total surface area.
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Affiliation(s)
- Matias I Maturana
- Centre for Neural Engineering, University of Melbourne, 203 Bouverie St, Carlton, Vic, 3053, Australia
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30
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Roggenhofer E, Fidzinski P, Shor O, Behr J. Reduced threshold for induction of LTP by activation of dopamine D1/D5 receptors at hippocampal CA1-subiculum synapses. PLoS One 2013; 8:e62520. [PMID: 23626827 PMCID: PMC3633881 DOI: 10.1371/journal.pone.0062520] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 03/21/2013] [Indexed: 11/18/2022] Open
Abstract
The phasic release of dopamine in the hippocampal formation has been shown to facilitate the encoding of novel information. There is evidence that the subiculum operates as a detector and distributor of sensory information, which incorporates the novelty and relevance of signals received from CA1. The subiculum acts as the final hippocampal relay station for outgoing information. Subicular pyramidal cells have been classified as regular- and burst-spiking neurons. The goal of the present study was to study the effect of dopamine D1/D5 receptor activation on synaptic transmission and plasticity in the subicular regular-spiking neurons of 4–6 week old Wistar rats. We demonstrate that prior activation of D1/D5 receptors reduces the threshold for the induction of long-term potentiation (LTP) in subicular regular-spiking neurons. Our results indicate that D1/D5 receptor activation facilitates a postsynaptic form of LTP in subicular regular-spiking cells that is NMDA receptor-dependent, relies on postsynaptic Ca2+ signaling, and requires the activation of protein kinase A. The enhanced propensity of subicular regular-spiking cells to express postsynaptic LTP after activation of D1/D5 receptors provides an intriguing mechanism for the encoding of hippocampal output information.
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Affiliation(s)
- Elisabeth Roggenhofer
- Department of Psychiatry and Psychotherapy, Charite, Universitätsmedizin Berlin, Berlin, Germany.
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31
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Graves AR, Moore SJ, Bloss EB, Mensh BD, Kath WL, Spruston N. Hippocampal pyramidal neurons comprise two distinct cell types that are countermodulated by metabotropic receptors. Neuron 2013. [PMID: 23177962 DOI: 10.1016/j.neuron.2012.09.036] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Relating the function of neuronal cell types to information processing and behavior is a central goal of neuroscience. In the hippocampus, pyramidal cells in CA1 and the subiculum process sensory and motor cues to form a cognitive map encoding spatial, contextual, and emotional information, which they transmit throughout the brain. Do these cells constitute a single class or are there multiple cell types with specialized functions? Using unbiased cluster analysis, we show that there are two morphologically and electrophysiologically distinct principal cell types that carry hippocampal output. We show further that these two cell types are inversely modulated by the synergistic action of glutamate and acetylcholine acting on metabotropic receptors that are central to hippocampal function. Combined with prior connectivity studies, our results support a model of hippocampal processing in which the two pyramidal cell types are predominantly segregated into two parallel pathways that process distinct modalities of information.
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Affiliation(s)
- Austin R Graves
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA
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32
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Cholinergic receptor activation induces a relative facilitation of synaptic responses in the entorhinal cortex during theta- and gamma-frequency stimulation of parasubicular inputs. Neuroscience 2013. [DOI: 10.1016/j.neuroscience.2012.11.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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33
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Arencibia-Albite F, Vázquez R, Velásquez-Martinez MC, Jiménez-Rivera CA. Cocaine sensitization inhibits the hyperpolarization-activated cation current Ih and reduces cell size in dopamine neurons of the ventral tegmental area. J Neurophysiol 2012; 107:2271-82. [PMID: 22262829 DOI: 10.1152/jn.00818.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The progressive augmentation of motor activity that results from repeated cocaine administration is termed behavioral sensitization. This phenomenon is thought to be a critical component in compulsive drug taking and relapse. Still, the cellular mechanisms that underlie sensitization remain elusive. Cocaine abuse, nonetheless, is known to evoke neuroplastic adaptations in dopamine (DA) neurotransmission originating from the midbrain's ventral tegmental area (VTA). Here, we report that concomitant with the development of locomotor sensitization to cocaine the hyperpolarization-activated cation current (I(h)) amplitude is depressed by ∼40% in VTA DA cells. Such effect did not result from a negative shift in I(h) voltage dependence. Nonstationary fluctuation analysis indicates that this inhibition was caused by an ∼45% reduction in the number of h-channels with no change in their unitary properties. The cocaine-induced I(h) depression was accompanied by a reduction in cell capacitance of similar magnitude (∼33%), leaving h-current density unaltered. Two implications follow from these data. First, I(h) inhibition may contribute to cocaine addiction by increasing bursting probability in DA cells and this effect could be intensified by the decrease in cell capacitance. Second, the cocaine-induced diminution of DA cell capacitance may also lead to reward tolerance promoting drug-seeking behaviors.
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34
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Hájos N, Holderith N, Németh B, Papp OI, Szabó GG, Zemankovics R, Freund TF, Haller J. The effects of an Echinacea preparation on synaptic transmission and the firing properties of CA1 pyramidal cells in the hippocampus. Phytother Res 2011; 26:354-62. [PMID: 21717515 DOI: 10.1002/ptr.3556] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 04/26/2011] [Accepted: 04/29/2011] [Indexed: 01/30/2023]
Abstract
Traditionally, Echinacea preparations are used as antiinflammatory agents and immune-enhancers. In addition to these effects, their anxiolytic potency has been recognized recently in laboratory tests. Our aim in this study was to uncover the potential effects of an Echinacea preparation on neuronal operations in the hippocampus, a brain region that is involved in anxiety and anxiety-related behaviors. Using in vitro electrophysiological techniques, we observed that excitatory synaptic transmission in hippocampal slices was significantly suppressed by an Echinacea extract found to be effective in anxiety tests. In contrast, no change in inhibitory synaptic transmission could be detected upon application of this extract. In addition, our experiments revealed that at low concentration the Echinacea extract reduced the spiking activity of CA1 pyramidal cells, while at high concentration increased it. This latter observation was parallel to the reduction in the magnitude of the h-current-mediated voltage responses in pyramidal cells. At any concentrations, the passive membrane properties of CA1 pyramidal cells were found to be unaltered by the Echinacea extract. In summary, the Echinacea extract can significantly regulate excitatory, but not inhibitory, synaptic transmission in the hippocampus, and this action might be involved in its anxiolytic effects observed in behaviour tests.
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Affiliation(s)
- Norbert Hájos
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
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35
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Modelling intrinsic electrophysiological properties of ON and OFF retinal ganglion cells. J Comput Neurosci 2011; 31:547-61. [PMID: 21431392 DOI: 10.1007/s10827-011-0322-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 01/11/2011] [Accepted: 02/27/2011] [Indexed: 10/18/2022]
Abstract
ON and OFF retinal ganglion cells (RGCs) display differences in their intrinsic electrophysiology: OFF cells maintain spontaneous activity in the absence of any input, exhibit subthreshold membrane potential oscillations, rebound excitation and burst firing; ON cells require excitatory input to drive their activity and display none of the aforementioned phenomena. The goal of this study was to identify and characterize ionic currents that explain these intrinsic electrophysiological differences between ON and OFF RGCs. A mathematical model of the electrophysiological properties of ON and OFF RGCs was constructed and validated using published patch-clamp data from isolated intact mouse retina. The model incorporates three ionic currents hypothesized to play a role in generating behaviors that are different between ON and OFF RGCs. These currents are persistent Na( + ), I (NaP), hyperpolarization-activated, I (h), and low voltage activated Ca(2 + ), I (T), currents. Using computer simulations of Hodgkin-Huxley type neuron with a single compartment model we found two distinct sets of I (NaP), I (h), I (T) conductances that correspond to ON and OFF RGCs populations. Simulations indicated that special properties of I (T) explain the differences in intrinsic electrophysiology between ON and OFF RGCs examined here. The modelling shows that the maximum conductance of I (T) is higher in OFF than in ON cells, in agreement with recent experimental data.
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36
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Kameneva T, Meffin H, Burkitt AN. Differential stimulation of ON and OFF retinal ganglion cells: a modeling study. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2011; 2010:4246-9. [PMID: 21096639 DOI: 10.1109/iembs.2010.5627176] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A model of the electrophysiological properties of ON and OFF retinal ganglion cells (RGCs) was constrained and validated using experimental data from the literature. Our simulations support experimental findings that differences in the magnitude of the T-type Ca(2+) current explain differences in the intrinsic electrophysiology of ON and OFF RGCs. The models are used to investigate the potential for differential stimulation of ON and OFF RGCs during neuroprosthetic stimulation with sinusoidal current. The model predicts that OFF cells fire preferential over ON cells in a frequency band around 10 Hz.
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Affiliation(s)
- Tatiana Kameneva
- Department of Electrical Engineering, The University of Melbourn, Australia.
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37
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Kameneva T, Grayden DB, Meffin H, Burkitt AN. Simulating electrical stimulation of degenerative retinal ganglion cells with bi-phasic pulse trains. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2011; 2011:7103-7106. [PMID: 22255975 DOI: 10.1109/iembs.2011.6091795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim of this work was to investigate how retinal ganglion cells (RGCs) respond to repetitive electrical stimulation in degenerative retina. The response of modeled ON and OFF cells was examined to bi-phasic pulse train stimulation of varying frequencies. Previously developed models of RGCs were extended to include an experimentally observable balance of excitatory and inhibitory currents in degenerative retina. The phenomena of fading and dark phosphenes with retinal implants were investigated. A hypothesis for a mechanism contributing to these phenomena was formulated.
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Affiliation(s)
- Tatiana Kameneva
- Department of Electrical and Electronic Engineering, The University of Melbourne.
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38
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Hyperpolarization-activated current (I(h)) in ganglion-cell photoreceptors. PLoS One 2010; 5:e15344. [PMID: 21187958 PMCID: PMC3004865 DOI: 10.1371/journal.pone.0015344] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 11/10/2010] [Indexed: 12/31/2022] Open
Abstract
Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin and serve as the primary retinal drivers of non-image-forming visual functions such as circadian photoentrainment, the pupillary light reflex, and suppression of melatonin production in the pineal. Past electrophysiological studies of these cells have focused on their intrinsic photosensitivity and synaptic inputs. Much less is known about their voltage-gated channels and how these might shape their output to non-image-forming visual centers. Here, we show that rat ipRGCs retrolabeled from the suprachiasmatic nucleus (SCN) express a hyperpolarization-activated inwardly-rectifying current (Ih). This current is blocked by the known Ih blockers ZD7288 and extracellular cesium. As in other systems, including other retinal ganglion cells, Ih in ipRGCs is characterized by slow kinetics and a slightly greater permeability for K+ than for Na+. Unlike in other systems, however, Ih in ipRGCs apparently does not actively contribute to resting membrane potential. We also explore non-specific effects of the common Ih blocker ZD7288 on rebound depolarization and evoked spiking and discuss possible functional roles of Ih in non-image-forming vision. This study is the first to characterize Ih in a well-defined population of retinal ganglion cells, namely SCN-projecting ipRGCs.
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39
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Radulescu AR. Mechanisms explaining transitions between tonic and phasic firing in neuronal populations as predicted by a low dimensional firing rate model. PLoS One 2010; 5:e12695. [PMID: 20877649 PMCID: PMC2943909 DOI: 10.1371/journal.pone.0012695] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 08/13/2010] [Indexed: 11/18/2022] Open
Abstract
Several firing patterns experimentally observed in neural populations have been successfully correlated to animal behavior. Population bursting, hereby regarded as a period of high firing rate followed by a period of quiescence, is typically observed in groups of neurons during behavior. Biophysical membrane-potential models of single cell bursting involve at least three equations. Extending such models to study the collective behavior of neural populations involves thousands of equations and can be very expensive computationally. For this reason, low dimensional population models that capture biophysical aspects of networks are needed. The present paper uses a firing-rate model to study mechanisms that trigger and stop transitions between tonic and phasic population firing. These mechanisms are captured through a two-dimensional system, which can potentially be extended to include interactions between different areas of the nervous system with a small number of equations. The typical behavior of midbrain dopaminergic neurons in the rodent is used as an example to illustrate and interpret our results. The model presented here can be used as a building block to study interactions between networks of neurons. This theoretical approach may help contextualize and understand the factors involved in regulating burst firing in populations and how it may modulate distinct aspects of behavior.
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Affiliation(s)
- Anca R Radulescu
- Department of Psychology, University of Colorado, Boulder, Colorado, USA.
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40
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Szücs A, Berton F, Nowotny T, Sanna P, Francesconi W. Consistency and diversity of spike dynamics in the neurons of bed nucleus of stria terminalis of the rat: a dynamic clamp study. PLoS One 2010; 5:e11920. [PMID: 20689810 PMCID: PMC2914744 DOI: 10.1371/journal.pone.0011920] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 07/07/2010] [Indexed: 11/19/2022] Open
Abstract
Neurons display a high degree of variability and diversity in the expression and regulation of their voltage-dependent ionic channels. Under low level of synaptic background a number of physiologically distinct cell types can be identified in most brain areas that display different responses to standard forms of intracellular current stimulation. Nevertheless, it is not well understood how biophysically different neurons process synaptic inputs in natural conditions, i.e., when experiencing intense synaptic bombardment in vivo. While distinct cell types might process synaptic inputs into different patterns of action potentials representing specific “motifs” of network activity, standard methods of electrophysiology are not well suited to resolve such questions. In the current paper we performed dynamic clamp experiments with simulated synaptic inputs that were presented to three types of neurons in the juxtacapsular bed nucleus of stria terminalis (jcBNST) of the rat. Our analysis on the temporal structure of firing showed that the three types of jcBNST neurons did not produce qualitatively different spike responses under identical patterns of input. However, we observed consistent, cell type dependent variations in the fine structure of firing, at the level of single spikes. At the millisecond resolution structure of firing we found high degree of diversity across the entire spectrum of neurons irrespective of their type. Additionally, we identified a new cell type with intrinsic oscillatory properties that produced a rhythmic and regular firing under synaptic stimulation that distinguishes it from the previously described jcBNST cell types. Our findings suggest a sophisticated, cell type dependent regulation of spike dynamics of neurons when experiencing a complex synaptic background. The high degree of their dynamical diversity has implications to their cooperative dynamics and synchronization.
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Affiliation(s)
- Attila Szücs
- BioCircuits Institute, University of California San Diego, La Jolla, California, United States of America.
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41
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Watt AJ, Desai NS. Homeostatic Plasticity and STDP: Keeping a Neuron's Cool in a Fluctuating World. Front Synaptic Neurosci 2010; 2:5. [PMID: 21423491 PMCID: PMC3059670 DOI: 10.3389/fnsyn.2010.00005] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 05/17/2010] [Indexed: 11/23/2022] Open
Abstract
Spike-timing-dependent plasticity (STDP) offers a powerful means of forming and modifying neural circuits. Experimental and theoretical studies have demonstrated its potential usefulness for functions as varied as cortical map development, sharpening of sensory receptive fields, working memory, and associative learning. Even so, it is unlikely that STDP works alone. Unless changes in synaptic strength are coordinated across multiple synapses and with other neuronal properties, it is difficult to maintain the stability and functionality of neural circuits. Moreover, there are certain features of early postnatal development (e.g., rapid changes in sensory input) that threaten neural circuit stability in ways that STDP may not be well placed to counter. These considerations have led researchers to investigate additional types of plasticity, complementary to STDP, that may serve to constrain synaptic weights and/or neuronal firing. These are collectively known as “homeostatic plasticity” and include schemes that control the total synaptic strength of a neuron, that modulate its intrinsic excitability as a function of average activity, or that make the ability of synapses to undergo Hebbian modification depend upon their history of use. In this article, we will review the experimental evidence for homeostatic forms of plasticity and consider how they might interact with STDP during development, and learning and memory.
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Affiliation(s)
- Alanna J Watt
- Wolfson Institute for Biomedical Research, University College London London, UK
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42
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Inyushin MU, Arencibia-Albite F, Vázquez-Torres R, Vélez-Hernández ME, Jiménez-Rivera CA. Alpha-2 noradrenergic receptor activation inhibits the hyperpolarization-activated cation current (Ih) in neurons of the ventral tegmental area. Neuroscience 2010; 167:287-97. [PMID: 20122999 PMCID: PMC2854519 DOI: 10.1016/j.neuroscience.2010.01.052] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 12/28/2009] [Accepted: 01/25/2010] [Indexed: 01/13/2023]
Abstract
The ventral tegmental area (VTA) is the source of dopaminergic projections innervating cortical structures and ventral forebrain. Dysfunction of this mesocorticolimbic system is critically involved in psychiatric disorders such as addiction and schizophrenia. Changes in VTA dopamine (DA) neuronal activity can alter neurotransmitter release at target regions which modify information processing in the reward circuit. Here we studied the effect of alpha-2 noradrenergic receptor activation on the hyperpolarization-activated cation current (I(h)) in DA neurons of the rat VTA. Brain slice preparations using whole-cell current and voltage-clamp techniques were employed. Clonidine and UK14304 (alpha-2 receptor selective agonists) were found to decrease I(h) amplitude and to slow its rate of activation indicating a negative shift in the current's voltage dependence. Two non-subtype-selective alpha-2 receptor antagonists, yohimbine and RS79948, prevented the effects of alpha-2 receptor activation. RX821002, a noradrenergic antagonist specific for alpha-2A and alpha-2D did not prevent I(h) inhibition. This result suggests that clonidine might be acting via an alpha-2C subtype since this receptor is the most abundant variant in the VTA. Analysis of a second messenger system associated with the alpha-2 receptor revealed that I(h) inhibition is independent of cyclic AMP (cAMP) and resulted from the activation of protein kinase C. It is suggested that the alpha-2 mediated hyperpolarizing shift in I(h) voltage dependence can facilitate the transition from pacemaker firing to afferent-driven burst activity. This transition may play a key role on the changes in synaptic plasticity that occurs in the mesocorticolimbic system under pathological conditions.
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Affiliation(s)
- M U Inyushin
- Department of Physiology, Universidad Central del Caribe, Medical School, PO Box 60-327, Bayamón, Puerto Rico
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Tunstall B, Agnew ZK, Panzeri S, Gigg J. Naturalistic stimulus trains evoke reproducible subicular responses both within and between animals in vivo. Hippocampus 2009; 20:252-63. [PMID: 19452520 DOI: 10.1002/hipo.20629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Previous investigation of CA1-evoked subicular responses has used either single low-frequency pulses (LF), paired-pulses (PP), or high-frequency bursts. Here we test for the first time how subiculum responds to naturalistic stimulation trains (NSTs). We recorded CA1-evoked field potentials from dorsal rat subiculum in response to LF, PP, and two NST patterns. The latter were derived from CA1 place cell activity; NST1 contained bursts of stimuli presented in two main episodes, while the burst-patterned stimuli in NST2 were spaced more evenly. NSTs generated significantly greater field responses compared with LF or PP patterns. Response patterns to either NST were significantly correlated across trial repeats in 9 out of 10 rats, supporting a robust postsynaptic encoding of CA1 input by subiculum. Correlations between NST responses were also observed across experiments; however, these were more variable than those within experiments. The relationship between response magnitude and activation history revealed a strong correlation between magnitude and NST instantaneous frequency for NST1 but was weaker for NST2. In addition, the number of stimuli within a prior 500 ms window was a determining factor for response magnitude for both NSTs. Overall, the robust reproducibility in subicular responses within rats suggests that information within NSTs is faithfully transmitted through the CA1-subiculum axis. However, variation in response sequences across rats suggests that encoding patterns to the same input differ across the subiculum. Changes in the ratio of target bursting and regularly spiking neurons along the subicular proximodistal axis may account for this variation. The activation history of this connection also appears to be a strong determining factor for response magnitude.
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Affiliation(s)
- Beth Tunstall
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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Srinivas KV, Sikdar SK. Epileptiform activity induces distance-dependent alterations of the Ca2+extrusion mechanism in the apical dendrites of subicular pyramidal neurons. Eur J Neurosci 2008; 28:2195-212. [DOI: 10.1111/j.1460-9568.2008.06519.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bender RA, Baram TZ. Hyperpolarization activated cyclic-nucleotide gated (HCN) channels in developing neuronal networks. Prog Neurobiol 2008; 86:129-40. [PMID: 18834920 PMCID: PMC2606691 DOI: 10.1016/j.pneurobio.2008.09.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 07/24/2008] [Accepted: 09/04/2008] [Indexed: 12/23/2022]
Abstract
Developing neuronal networks evolve continuously, requiring that neurons modulate both their intrinsic properties and their responses to incoming synaptic signals. Emerging evidence supports roles for the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in this neuronal plasticity. HCN channels seem particularly suited for fine-tuning neuronal properties and responses because of their remarkably large and variable repertoire of functions, enabling integration of a wide range of cellular signals. Here, we discuss the involvement of HCN channels in cortical and hippocampal network maturation, and consider potential roles of developmental HCN channel dysregulation in brain disorders such as epilepsy.
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Affiliation(s)
- Roland A. Bender
- Institute of Anatomy I, University of Hamburg, D-20246 Hamburg, Germany, Phone: +49-40-428034333, Fax: +49-40-428034966, E-mail:
| | - Tallie Z. Baram
- Departments Anatomy/Neurobiology, Pediatrics & Neurology, University of California, Irvine, CA 92697-4475, USA, Phone: +1-949-824-3307, Fax: +1-949-824-1106, E-mail:
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46
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Huggenberger S, Vater M, Deisz RA. Interlaminar Differences of Intrinsic Properties of Pyramidal Neurons in the Auditory Cortex of Mice. Cereb Cortex 2008; 19:1008-18. [DOI: 10.1093/cercor/bhn143] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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McDaid J, McElvain MA, Brodie MS. Ethanol effects on dopaminergic ventral tegmental area neurons during block of Ih: involvement of barium-sensitive potassium currents. J Neurophysiol 2008; 100:1202-10. [PMID: 18614756 DOI: 10.1152/jn.00994.2007] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The dopaminergic neurons of the ventral tegmental area (DA VTA neurons) are important for the rewarding and reinforcing properties of drugs of abuse, including ethanol. Ethanol increases the firing frequency of DA VTA neurons from rats and mice. Because of a recent report on block of ethanol excitation in mouse DA VTA neurons with ZD7288, a selective blocker of the hyperpolarization-activated cationic current Ih, we examined the effect of ZD7288 on ethanol excitation in DA VTA neurons from C57Bl/6J and DBA/2J mice and Fisher 344 rats. Ethanol (80 mM) caused only increases in firing rate in mouse DA VTA neurons in the absence of ZD7288, but in the presence of ZD7288 (30 microM), ethanol produced a more transient excitation followed by a decrease of firing. This same biphasic phenomenon was observed in DA VTA neurons from rats in the presence of ZD7288 only at very high ethanol concentrations (160-240 mM) but not at lower pharmacologically relevant concentrations. The longer latency ethanol-induced inhibition was not observed in DA VTA neurons from mice or rats in the presence of barium (100 microM), which blocks G protein-linked potassium channels (GIRKs) and other inwardly rectifying potassium channels. Ethanol may have a direct effect to increase an inhibitory potassium conductance, but this effect of ethanol can only decrease the firing rate if Ih is blocked.
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Affiliation(s)
- John McDaid
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, USA
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48
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Fidzinski P, Shor O, Behr J. Target-cell-specific bidirectional synaptic plasticity at hippocampal output synapses. Eur J Neurosci 2008; 27:1111-8. [PMID: 18312585 DOI: 10.1111/j.1460-9568.2008.06089.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is commonly accepted that the hippocampus is critically involved in the explicit memory formation of mammals. The subiculum is the principal target of CA1 pyramidal cells and thus serves as the major relay station for the outgoing hippocampal information. Pyramidal cells in the subiculum can be classified according to their firing properties into burst-spiking and regular-spiking cells. In the present study we demonstrate that burst-spiking and regular-spiking cells show fundamentally different forms of low frequency-induced synaptic plasticity in rats. In burst-spiking cells, low-frequency stimulation (at 0.5-5 Hz) induces frequency-dependent long-term depression (LTD) with a maximum at 1 Hz. This LTD is dependent on the activation of NMDAR and masks an mGluR-dependent long-term potentiation (LTP). In contrast, in regular-spiking cells low-frequency stimulation induces an mGluR-dependent LTP that masks an NMDAR-dependent LTD. Both processes depend on postsynaptic Ca(2+)-signaling as BAPTA prevents the induction of synaptic plasticity in both cell types. Thus, mGluR-dependent LTP and NMDAR-dependent LTD occur simultaneously at CA1-subiculum synapses and the predominant direction of synaptic plasticity relies on the cell type investigated. Our data indicate a novel mechanism for the sliding-threshold model of synaptic plasticity, in which induction of LTP and LTD seems to be driven by the relative activation state of NMDAR and mGluR. Our observation that the direction of synaptic plasticity correlates with the discharge properties of the postsynaptic cell reveals a novel and intriguing mechanism of target specificity that may serve in tuning the significance of neuronal information by trafficking hippocampal output onto either subicular burst-spiking or regular-spiking cells.
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Affiliation(s)
- Pawel Fidzinski
- Department of Psychiatry and Psychotherapy, Charité Universitätsmedizin Berlin, Chariteplatz 1, 10117 Berlin, Germany.
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Arencibia-Albite F, Paladini C, Williams JT, Jiménez-Rivera CA. Noradrenergic modulation of the hyperpolarization-activated cation current (Ih) in dopamine neurons of the ventral tegmental area. Neuroscience 2007; 149:303-14. [PMID: 17884297 PMCID: PMC2254936 DOI: 10.1016/j.neuroscience.2007.08.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 08/01/2007] [Accepted: 08/06/2007] [Indexed: 11/17/2022]
Abstract
Alterations in the state of excitability of midbrain dopamine (DA) neurons from the ventral tegmental area (VTA) may underlie changes in the synaptic plasticity of the mesocorticolimbic system. Here, we investigated norepinephrine's (NE) regulation of VTA DA cell excitability by modulation of the hyperpolarization-activated cation current, Ih, with whole cell recordings in rat brain slices. Current clamp recordings show that NE (40 microM) hyperpolarizes spontaneously firing VTA DA cells (11.23+/-4 mV; n=8). In a voltage clamp, NE (40 microM) induces an outward current (100+/-24 pA; n=8) at -60 mV that reverses at about the Nernst potential for potassium (-106 mV). In addition, NE (40 microM) increases the membrane cord conductance (179+/-42%; n=10) and reduces Ih amplitude (68+/-3% of control at -120 mV; n=10). The noradrenergic alpha-1 antagonist prazosin (40 microM; n=5) or the alpha-2 antagonist yohimbine (40 microM; n=5) did not block NE effects. All NE-evoked events were blocked by the D2 antagonists sulpiride (1 microM) and eticlopride (100 nM) and no significant reduction of Ih took place in the presence of the potassium channel blocker BaCl2 (300 microM). Therefore, it is concluded that NE inhibition of Ih was due to an increase in membrane conductance by a nonspecific activation of D2 receptors that induce an outward potassium current and is not a result of a second messenger system acting on h-channels. The results also suggest that Ih channels are mainly located at dendrites of VTA DA cells and, thus, their inhibition may facilitate the transition from single-spike firing to burst firing and vice versa.
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Affiliation(s)
- F Arencibia-Albite
- Department of Physiology, Universidad Central del Caribe, Bayamón, Puerto Rico
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Crasto CJ, Marenco LN, Liu N, Morse TM, Cheung KH, Lai PC, Bahl G, Masiar P, Lam HYK, Lim E, Chen H, Nadkarni P, Migliore M, Miller PL, Shepherd GM. SenseLab: new developments in disseminating neuroscience information. Brief Bioinform 2007; 8:150-62. [PMID: 17510162 PMCID: PMC2756159 DOI: 10.1093/bib/bbm018] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This article presents the latest developments in neuroscience information dissemination through the SenseLab suite of databases: NeuronDB, CellPropDB, ORDB, OdorDB, OdorMapDB, ModelDB and BrainPharm. These databases include information related to: (i) neuronal membrane properties and neuronal models, and (ii) genetics, genomics, proteomics and imaging studies of the olfactory system. We describe here: the new features for each database, the evolution of SenseLab's unifying database architecture and instances of SenseLab database interoperation with other neuroscience online resources.
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Affiliation(s)
- Chiquito J Crasto
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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