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Trofimova AM, Amakhin DV, Postnikova TY, Tiselko VS, Alekseev A, Podoliak E, Gordeliy VI, Chizhov AV, Zaitsev AV. Light-Driven Sodium Pump as a Potential Tool for the Control of Seizures in Epilepsy. Mol Neurobiol 2024; 61:4691-4704. [PMID: 38114761 DOI: 10.1007/s12035-023-03865-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 12/06/2023] [Indexed: 12/21/2023]
Abstract
The marine flavobacterium Krokinobactereikastus light-driven sodium pump (KR2) generates an outward sodium ion current under 530 nm light stimulation, representing a promising optogenetic tool for seizure control. However, the specifics of KR2 application to suppress epileptic activity have not yet been addressed. In the present study, we investigated the possibility of KR2 photostimulation to suppress epileptiform activity in mouse brain slices using the 4-aminopyrindine (4-AP) model. We injected the adeno-associated viral vector (AAV-PHP.eB-hSyn-KR2-YFP) containing the KR2 sodium pump gene enhanced with appropriate trafficking tags. KR2 expression was observed in the lateral entorhinal cortex and CA1 hippocampus. Using whole-cell patch clamp in mouse brain slices, we show that KR2, when stimulated with LED light, induces a substantial hyperpolarization of entorhinal neurons. However, continuous photostimulation of KR2 does not interrupt ictal discharges in mouse entorhinal cortex slices induced by a solution containing 4-AP. KR2-induced hyperpolarization strongly activates neuronal HCN channels. Consequently, turning off photostimulation resulted in HCN channel-mediated rebound depolarization accompanied by a transient increase in spontaneous network activity. Using low-frequency pulsed photostimulation, we induced the generation of short HCN channel-mediated discharges that occurred in response to the light stimulus being turned off; these discharges reliably interrupt ictal activity. Thus, low-frequency pulsed photostimulation of KR2 can be considered as a potential tool for controlling epileptic seizures.
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Affiliation(s)
- Alina M Trofimova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
| | - Dmitry V Amakhin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
| | - Tatyana Y Postnikova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
| | - Vasilii S Tiselko
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
| | - Alexey Alekseev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Elizaveta Podoliak
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Department of Ophthalmology, Universitäts-Augenklinik Bonn, University of Bonn, Bonn, Germany
| | - Valentin I Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Anton V Chizhov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
- MathNeuro Team, Inria Centre at Université Côte d'Azur, Sophia Antipolis, France
| | - Aleksey V Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia.
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Villalobos N. Disinhibition Is an Essential Network Motif Coordinated by GABA Levels and GABA B Receptors. Int J Mol Sci 2024; 25:1340. [PMID: 38279339 PMCID: PMC10816949 DOI: 10.3390/ijms25021340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/16/2024] [Accepted: 01/19/2024] [Indexed: 01/28/2024] Open
Abstract
Network dynamics are crucial for action and sensation. Changes in synaptic physiology lead to the reorganization of local microcircuits. Consequently, the functional state of the network impacts the output signal depending on the firing patterns of its units. Networks exhibit steady states in which neurons show various activities, producing many networks with diverse properties. Transitions between network states determine the output signal generated and its functional results. The temporal dynamics of excitation/inhibition allow a shift between states in an operational network. Therefore, a process capable of modulating the dynamics of excitation/inhibition may be functionally important. This process is known as disinhibition. In this review, we describe the effect of GABA levels and GABAB receptors on tonic inhibition, which causes changes (due to disinhibition) in network dynamics, leading to synchronous functional oscillations.
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Affiliation(s)
- Nelson Villalobos
- Academia de Fisiología, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, Ciudad de México 11340, Mexico;
- Sección de Estudios Posgrado e Investigación de la Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, Ciudad de Mexico 11340, Mexico
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3
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Smyre SA, Bean NL, Stein BE, Rowland BA. Predictability alters multisensory responses by modulating unisensory inputs. Front Neurosci 2023; 17:1150168. [PMID: 37065927 PMCID: PMC10090419 DOI: 10.3389/fnins.2023.1150168] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/13/2023] [Indexed: 03/30/2023] Open
Abstract
The multisensory (deep) layers of the superior colliculus (SC) play an important role in detecting, localizing, and guiding orientation responses to salient events in the environment. Essential to this role is the ability of SC neurons to enhance their responses to events detected by more than one sensory modality and to become desensitized (‘attenuated’ or ‘habituated’) or sensitized (‘potentiated’) to events that are predictable via modulatory dynamics. To identify the nature of these modulatory dynamics, we examined how the repetition of different sensory stimuli affected the unisensory and multisensory responses of neurons in the cat SC. Neurons were presented with 2HZ stimulus trains of three identical visual, auditory, or combined visual–auditory stimuli, followed by a fourth stimulus that was either the same or different (‘switch’). Modulatory dynamics proved to be sensory-specific: they did not transfer when the stimulus switched to another modality. However, they did transfer when switching from the visual–auditory stimulus train to either of its modality-specific component stimuli and vice versa. These observations suggest that predictions, in the form of modulatory dynamics induced by stimulus repetition, are independently sourced from and applied to the modality-specific inputs to the multisensory neuron. This falsifies several plausible mechanisms for these modulatory dynamics: they neither produce general changes in the neuron’s transform, nor are they dependent on the neuron’s output.
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Villalobos CA, Basso MA. Optogenetic activation of the inhibitory nigro-collicular circuit evokes contralateral orienting movements in mice. Cell Rep 2022; 39:110699. [PMID: 35443172 PMCID: PMC10144672 DOI: 10.1016/j.celrep.2022.110699] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/20/2021] [Accepted: 03/29/2022] [Indexed: 11/03/2022] Open
Abstract
We report that increasing inhibition from the basal ganglia (BG) to the superior colliculus (SC) through the substantia nigra pars reticulata (nigra) using in vivo optogenetic activation of GABAergic terminals in mice produces contralateral orienting movements. These movements are unexpected because decreases, and not increases, in nigral activity are generally associated with the initiation of orienting movements. We found that, in slice recordings, the same optogenetic stimulation of nigral terminals producing movements in vivo evokes post-inhibitory rebound depolarization followed by Na+ spikes in SC output neurons. Moreover, blocking T-type Ca2+ channels in slices prevent post-inhibitory rebound and subsequent Na+ spiking in SC output neurons and also reduce the likelihood of contralateral orienting in vivo. On the basis of these results, we propose that, in addition to the permissive role, the BG may play an active role in the generation of orienting movements in mice by driving post-inhibitory rebound depolarization in SC output neurons.
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Affiliation(s)
- Claudio A Villalobos
- Fuster Laboratory of Cognitive Neuroscience, Department of Psychiatry and Biobehavioral Sciences, The Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
| | - Michele A Basso
- Fuster Laboratory of Cognitive Neuroscience, Department of Psychiatry and Biobehavioral Sciences, The Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
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5
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Zhu M, Yan Y, Cao X, Zeng F, Xu G, Shen W, Li F, Luo L, Wang Z, Zhang Y, Zhang X, Zhang D, Liu T. Electrophysiological and Morphological Features of Rebound Depolarization Characterized Interneurons in Rat Superficial Spinal Dorsal Horn. Front Cell Neurosci 2021; 15:736879. [PMID: 34621158 PMCID: PMC8490703 DOI: 10.3389/fncel.2021.736879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 08/25/2021] [Indexed: 11/18/2022] Open
Abstract
Substantia gelatinosa (SG) neurons, which are located in the spinal dorsal horn (lamina II), have been identified as the “central gate” for the transmission and modulation of nociceptive information. Rebound depolarization (RD), a biophysical property mediated by membrane hyperpolarization that is frequently recorded in the central nervous system, contributes to shaping neuronal intrinsic excitability and, in turn, contributes to neuronal output and network function. However, the electrophysiological and morphological properties of SG neurons exhibiting RD remain unclarified. In this study, whole-cell patch-clamp recordings were performed on SG neurons from parasagittal spinal cord slices. RD was detected in 44.44% (84 out of 189) of the SG neurons recorded. We found that RD-expressing neurons had more depolarized resting membrane potentials, more hyperpolarized action potential (AP) thresholds, higher AP amplitudes, shorter AP durations, and higher spike frequencies in response to depolarizing current injection than neurons without RD. Based on their firing patterns and morphological characteristics, we propose that most of the SG neurons with RD mainly displayed tonic firing (69.05%) and corresponded to islet cell morphology (58.82%). Meanwhile, subthreshold currents, including the hyperpolarization-activated cation current (Ih) and T-type calcium current (IT), were identified in SG neurons with RD. Blockage of Ih delayed the onset of the first spike in RD, while abolishment of IT significantly blunted the amplitude of RD. Regarding synaptic inputs, SG neurons with RD showed lower frequencies in both spontaneous and miniature excitatory synaptic currents. Furthermore, RD-expressing neurons received either Aδ- or C-afferent-mediated monosynaptic and polysynaptic inputs. However, RD-lacking neurons received afferents from monosynaptic and polysynaptic Aδ fibers and predominantly polysynaptic C-fibers. These findings demonstrate that SG neurons with RD have a specific cell-type distribution, and may differentially process somatosensory information compared to those without RD.
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Affiliation(s)
- Mengye Zhu
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Yi Yan
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Xuezhong Cao
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Fei Zeng
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Gang Xu
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Wei Shen
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Fan Li
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Lingyun Luo
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Zhijian Wang
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Yong Zhang
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Xuexue Zhang
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Daying Zhang
- Department of Pain Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Institute of Pain Medicine, Jiangxi Academy of Clinical and Medical Sciences, Nanchang, China
| | - Tao Liu
- Center for Experimental Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China
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Liu X, Li H, Wang Y, Lei T, Wang J, Spillmann L, Andolina IM, Wang W. From Receptive to Perceptive Fields: Size-Dependent Asymmetries in Both Negative Afterimages and Subcortical On and Off Post-Stimulus Responses. J Neurosci 2021; 41:7813-7830. [PMID: 34326144 PMCID: PMC8445057 DOI: 10.1523/jneurosci.0300-21.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 07/11/2021] [Accepted: 07/13/2021] [Indexed: 11/21/2022] Open
Abstract
Negative afterimages are perceptual phenomena that occur after physical stimuli disappear from sight. Their origin is linked to transient post-stimulus responses of visual neurons. The receptive fields (RFs) of these subcortical ON- and OFF-center neurons exhibit antagonistic interactions between central and surrounding visual space, resulting in selectivity for stimulus polarity and size. These two features are closely intertwined, yet their relationship to negative afterimage perception remains unknown. Here we tested whether size differentially affects the perception of bright and dark negative afterimages in humans of both sexes, and how this correlates with neural mechanisms in subcortical ON and OFF cells. Psychophysically, we found a size-dependent asymmetry whereby dark disks produce stronger and longer-lasting negative afterimages than bright disks of equal contrast at sizes >0.8°. Neurophysiological recordings from retinal and relay cells in female cat dorsal lateral geniculate nucleus showed that subcortical ON cells exhibited stronger sustained post-stimulus responses to dark disks, than OFF cells to bright disks, at sizes >1°. These sizes agree with the emergence of center-surround antagonism, revealing stronger suppression to opposite-polarity stimuli for OFF versus ON cells, particularly in dorsal lateral geniculate nucleus. Using a network-based retino-geniculate model, we confirmed stronger antagonism and temporal transience for OFF-cell post-stimulus rebound responses. A V1 population model demonstrated that both strength and duration asymmetries can be propagated to downstream cortical areas. Our results demonstrate how size-dependent antagonism impacts both the neuronal post-stimulus response and the resulting afterimage percepts, thereby supporting the idea of perceptual RFs reflecting the underlying neuronal RF organization of single cells.SIGNIFICANCE STATEMENT Visual illusions occur when sensory inputs and perceptual outcomes do not match, and provide a valuable tool to understand transformations from neural to perceptual responses. A classic example are negative afterimages that remain visible after a stimulus is removed from view. Such perceptions are linked to responses in early visual neurons, yet the details remain poorly understood. Combining human psychophysics, neurophysiological recordings in cats and retino-thalamo-cortical computational modeling, our study reveals how stimulus size and the receptive-field structure of subcortical ON and OFF cells contributes to the parallel asymmetries between neural and perceptual responses to bright versus dark afterimages. Thus, this work provides a deeper link from the underlying neural mechanisms to the resultant perceptual outcomes.
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Affiliation(s)
- Xu Liu
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hui Li
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ye Wang
- State Key Laboratory of Media Convergence and Communication, Neuroscience and Intelligent Media Institute, Communication University of China, Beijing, 100024, China
| | - Tianhao Lei
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Jijun Wang
- Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Psychotic Disorders, Shanghai, 200030, China
| | - Lothar Spillmann
- Department of Neurology, University of Freiburg, Freiburg, 79085, Germany
| | - Ian Max Andolina
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
- Shanghai Center for Brain and Brain-inspired Intelligence Technology, Shanghai, 200031, China
| | - Wei Wang
- Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, State Key Laboratory of Neuroscience, Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, 200031, China
- Shanghai Center for Brain and Brain-inspired Intelligence Technology, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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7
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Cooke JE, Lee JJ, Bartlett EL, Wang X, Bendor D. Post-stimulatory activity in primate auditory cortex evoked by sensory stimulation during passive listening. Sci Rep 2020; 10:13885. [PMID: 32807854 PMCID: PMC7431571 DOI: 10.1038/s41598-020-70397-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 07/17/2020] [Indexed: 01/04/2023] Open
Abstract
Under certain circumstances, cortical neurons are capable of elevating their firing for long durations in the absence of a stimulus. Such activity has typically been observed and interpreted in the context of performance of a behavioural task. Here we investigated whether post-stimulatory activity is observed in auditory cortex and the medial geniculate body of the thalamus in the absence of any explicit behavioural task. We recorded spiking activity from single units in the auditory cortex (fields A1, R and RT) and auditory thalamus of awake, passively-listening marmosets. We observed post-stimulatory activity that lasted for hundreds of milliseconds following the termination of the acoustic stimulus. Post-stimulatory activity was observed following both adapting, sustained and suppressed response profiles during the stimulus. These response types were observed across all cortical fields tested, but were largely absent from the auditory thalamus. As well as being of shorter duration, thalamic post-stimulatory activity emerged following a longer latency than in cortex, indicating that post-stimulatory activity may be generated within auditory cortex during passive listening. Given that these responses were observed in the absence of an explicit behavioural task, post-stimulatory activity in sensory cortex may play a functional role in processes such as echoic memory and temporal integration that occur during passive listening.
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Affiliation(s)
- James E Cooke
- Institute of Behavioural Neuroscience (IBN), University College London (UCL), London, WC1H 0AP, UK.
| | - Julie J Lee
- Institute of Behavioural Neuroscience (IBN), University College London (UCL), London, WC1H 0AP, UK
- Institute of Ophthalmology, University College London (UCL), London, WC1H 0AP, UK
| | - Edward L Bartlett
- Departments of Biological Sciences and Biomedical Engineering, Purdue University, West Lafayette, 47907, USA
| | - Xiaoqin Wang
- Departments of Biomedical Engineering, Johns Hopkins University, Baltimore, 21205, USA
| | - Daniel Bendor
- Institute of Behavioural Neuroscience (IBN), University College London (UCL), London, WC1H 0AP, UK
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Valdés-Baizabal C, Casado-Román L, Bartlett EL, Malmierca MS. In vivo whole-cell recordings of stimulus-specific adaptation in the inferior colliculus. Hear Res 2020; 399:107978. [PMID: 32402412 DOI: 10.1016/j.heares.2020.107978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/17/2020] [Accepted: 04/18/2020] [Indexed: 12/31/2022]
Abstract
The inferior colliculus is an auditory structure where inputs from multiple lower centers converge, allowing the emergence of complex coding properties of auditory information such as stimulus-specific adaptation. Stimulus-specific adaptation is the adaptation of neuronal responses to a specific repeated stimulus, which does not entirely generalize to other new stimuli. This phenomenon provides a mechanism to emphasize saliency and potentially informative sensory inputs. Stimulus-specific adaptation has been traditionally studied analyzing the somatic spiking output. However, studies that correlate within the same inferior colliculus neurons their intrinsic properties, subthreshold responses and the level of acoustic stimulus-specific adaptation are still pending. For this, we recorded in vivo whole-cell patch-clamp neurons in the mouse inferior colliculus while stimulating with current injections or the classic auditory oddball paradigm. Our data based on cases of ten neuron, suggest that although passive properties were similar, intrinsic properties differed between adapting and non-adapting neurons. Non-adapting neurons showed a sustained-regular firing pattern that corresponded to central nucleus neurons and adapting neurons at the inferior colliculus cortices showed variable firing patterns. Our current results suggest that synaptic stimulus-specific adaptation was variable and could not be used to predict the presence of spiking stimulus-specific adaptation. We also observed a small trend towards hyperpolarized membrane potentials in adapting neurons and increased synaptic inhibition with consecutive stimulus repetitions in all neurons. This finding indicates a more simple type of adaptation, potentially related to potassium conductances. Hence, these data represent a modest first step in the intracellular study of stimulus-specific adaptation in inferior colliculus neurons in vivo that will need to be expanded with pharmacological manipulations to disentangle specific ionic channels participation.
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Affiliation(s)
- Catalina Valdés-Baizabal
- Cognitive and Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León, University of Salamanca, 37007, Salamanca, Spain; The Salamanca Institute for Biomedical Research (IBSAL), 37007, Salamanca, Spain
| | - Lorena Casado-Román
- Cognitive and Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León, University of Salamanca, 37007, Salamanca, Spain; The Salamanca Institute for Biomedical Research (IBSAL), 37007, Salamanca, Spain
| | - Edward L Bartlett
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA; Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Manuel S Malmierca
- Cognitive and Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León, University of Salamanca, 37007, Salamanca, Spain; The Salamanca Institute for Biomedical Research (IBSAL), 37007, Salamanca, Spain; Department of Cell Biology and Pathology, Faculty of Medicine, Campus Miguel de Unamuno, University of Salamanca, 37007, Salamanca, Spain.
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9
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Zhang Y, Garcia E, Sack AS, Snutch TP. L-type calcium channel contributions to intrinsic excitability and synaptic activity during basolateral amygdala postnatal development. J Neurophysiol 2020; 123:1216-1235. [PMID: 31967931 DOI: 10.1152/jn.00606.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The amygdala contributes toward emotional processes such as fear, anxiety, and social cognition. Furthermore, evidence suggests that increased excitability of basolateral amygdala (BLA) principal neurons underlie certain neuropsychiatric disorders. Gain-of-function mutations in neuronal L-type calcium channels (LTCCs) are linked to neurodevelopmental diseases, including autism spectrum disorders (ASDs). While LTCCs are expressed throughout the BLA, direct evidence for increased LTCC activity affecting BLA excitability and potentially contributing to disease pathophysiology is lacking. In this study, we utilized a pharmacological approach to examine the contributions of LTCCs to BLA principal cell excitability and synaptic activity at immature (postnatal day 7, P7) and juvenile (P21) developmental stages. Acute upregulation of LTCC activity in brain slices by application of the agonist (S)-Bay K 8644 resulted in increased intrinsic excitability properties including firing frequency response, plateau potential, and spike-frequency adaptation selectively in P7 neurons. Contrastingly, for P21 neurons, the main effect of (S)-Bay K 8644 was to enhance burst firing. (S)-Bay K 8644 increased spontaneous inhibitory synaptic currents at both P7 and P21 but did not affect evoked synaptic currents at either stage. (S)-Bay K 8644 did not alter P7 spontaneous excitatory synaptic currents, although it increased current amplitude in P21 neurons. Overall, the results provide support for the notion that alteration of LTCC activity at specific periods of early brain development may lead to functional alterations to neuronal network activity and subsequently contribute to underlying mechanisms of amygdala-related neurological disorders.NEW & NOTEWORTHY The role of L-type calcium channels (LTCCs) in regulating neuronal electrophysiological properties during development remains unclear. We show that in basolateral amygdala principal neurons, an increase of LTCC activity alters both neuronal excitability and synaptic activity. The results also provide evidence for the distinct contributions of LTCCs at different stages of neurodevelopment and shed insight into our understanding of LTCC dysfunction in amygdala-related neurological disorders.
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Affiliation(s)
- Yiming Zhang
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Esperanza Garcia
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Anne-Sophie Sack
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Terrance P Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
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Kopp-Scheinpflug C, Sinclair JL, Linden JF. When Sound Stops: Offset Responses in the Auditory System. Trends Neurosci 2018; 41:712-728. [DOI: 10.1016/j.tins.2018.08.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/30/2018] [Accepted: 08/10/2018] [Indexed: 11/17/2022]
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11
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Jaffe DB, Brenner R. A computational model for how the fast afterhyperpolarization paradoxically increases gain in regularly firing neurons. J Neurophysiol 2018; 119:1506-1520. [PMID: 29357445 DOI: 10.1152/jn.00385.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The gain of a neuron, the number and frequency of action potentials triggered in response to a given amount of depolarizing injection, is an important behavior underlying a neuron's function. Variations in action potential waveform can influence neuronal discharges by the differential activation of voltage- and ion-gated channels long after the end of a spike. One component of the action potential waveform, the afterhyperpolarization (AHP), is generally considered an inhibitory mechanism for limiting firing rates. In dentate gyrus granule cells (DGCs) expressing fast-gated BK channels, large fast AHPs (fAHP) are paradoxically associated with increased gain. In this article, we describe a mechanism for this behavior using a computational model. Hyperpolarization provided by the fAHP enhances activation of a dendritic inward current (a T-type Ca2+ channel is suggested) that, in turn, boosts rebound depolarization at the soma. The model suggests that the fAHP may both reduce Ca2+ channel inactivation and, counterintuitively, enhance its activation. The magnitude of the rebound depolarization, in turn, determines the activation of a subsequent, slower inward current (a persistent Na+ current is suggested) limiting the interspike interval. Simulations also show that the effect of AHP on gain is also effective for physiologically relevant stimulation; varying AHP amplitude affects interspike interval across a range of "noisy" stimulus frequency and amplitudes. The mechanism proposed suggests that small fAHPs in DGCs may contribute to their limited excitability. NEW & NOTEWORTHY The afterhyperpolarization (AHP) is canonically viewed as a major factor underlying the refractory period, serving to limit neuronal firing rate. We recently reported that enhancing the amplitude of the fast AHP (fAHP) in a relatively slowly firing neuron (vs. fast spiking neurons) expressing fast-gated BK channels augments neuronal excitability. In this computational study, we present a novel, quantitative hypothesis for how varying the amplitude of the fAHP can, paradoxically, influence a subsequent spike tens of milliseconds later.
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Affiliation(s)
- David B Jaffe
- Department of Biology, UTSA Neurosciences Institute, University of Texas at San Antonio , San Antonio, Texas
| | - Robert Brenner
- Department of Cell and Integrative Physiology, University of Texas Health Science Center at San Antonio , San Antonio, Texas
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Asymmetries of Dark and Bright Negative Afterimages Are Paralleled by Subcortical ON and OFF Poststimulus Responses. J Neurosci 2017; 37:1984-1996. [PMID: 28077727 DOI: 10.1523/jneurosci.2021-16.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 12/21/2016] [Accepted: 01/02/2017] [Indexed: 01/01/2023] Open
Abstract
Humans are more sensitive to luminance decrements than increments, as evidenced by lower thresholds and shorter latencies for dark stimuli. This asymmetry is consistent with results of neurophysiological recordings in dorsal lateral geniculate nucleus (dLGN) and primary visual cortex (V1) of cat and monkey. Specifically, V1 population responses demonstrate that darks elicit higher levels of activation than brights, and the latency of OFF responses in dLGN and V1 is shorter than that of ON responses. The removal of a dark or bright disc often generates the perception of a negative afterimage, and here we ask whether there also exist asymmetries for negative afterimages elicited by dark and bright discs. If so, do the poststimulus responses of subcortical ON and OFF cells parallel such afterimage asymmetries? To test these hypotheses, we performed psychophysical experiments in humans and single-cell/S-potential recordings in cat dLGN. Psychophysically, we found that bright afterimages elicited by luminance decrements are stronger and last longer than dark afterimages elicited by luminance increments of equal sizes. Neurophysiologically, we found that ON cells responded to the removal of a dark disc with higher firing rates that were maintained for longer than OFF cells to the removal of a bright disc. The ON and OFF cell asymmetry was most pronounced at long stimulus durations in the dLGN. We conclude that subcortical response strength differences between ON and OFF channels parallel the asymmetries between bright and dark negative afterimages, further supporting a subcortical origin of bright and dark afterimage perception.SIGNIFICANCE STATEMENT Afterimages are physiological aftereffects following stimulation of the eye, the study of which helps us to understand how our visual brain generates visual perception in the absence of physical stimuli. We report, for the first time to our knowledge, asymmetries between bright and dark negative afterimages elicited by luminance decrements and increments, respectively. Bright afterimages are stronger and last longer than dark afterimages. Subcortical neuronal recordings of poststimulus responses of ON and OFF cells reveal similar asymmetries with respect to response strength and duration. Our results suggest that subcortical differences between ON and OFF channels help explain intensity and duration asymmetries between bright and dark afterimages, supporting the notion of a subcortical origin of bright and dark afterimages.
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李 凌, 张 达, 彭 斯, 吴 静, 蒋 昌, 柳 涛. [Rebound depolarization of substantia gelatinosa neurons and its modulatory mechanisms in rat spinal dorsal horn]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2016; 37:204-209. [PMID: 28219864 PMCID: PMC6779672 DOI: 10.3969/j.issn.1673-4254.2017.02.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To investigate the rebound depolarization of substantia gelatinosa (SG) neurons in rat spinal dorsal horn and explore its modulatory mechanisms to provide better insights into rebound depolarization-related diseases. METHODS Parasagittal slices of the spinal cord were prepared from 3- to 5-week-old Sprague-Dawley rats. The electrophysiologic characteristics and responses to hyperpolarization stimulation were recorded using whole-cell patch-clamp technique. The effects of hyperpolarization-activated cyclic nucleotide gated cation (HCN) channel blockers and T-type calcium channel blockers on rebound depolarization of the neurons were studied. RESULTS A total of 63 SG neurons were recorded. Among them, 23 neurons showed no rebound depolarization, 19 neurons showed rebound depolarization without spikes, and 21 neurons showed rebound depolarization with spikes. The action potential thresholds of the neurons without rebound depolarization were significantly higher than those of the neurons with rebound depolarization and spikes (-28.7∓1.6 mV vs -36.0∓2.0 mV, P<0.05). The two HCN channel blockers CsCl and ZD7288 significantly delayed the latency of rebound depolarization with spike from 45.9∓11.6 ms to 121.6∓51.3 ms (P<0.05) and from 36.2∓10.3 ms to 73.6∓13.6 ms (P<0.05), respectively. ZD7288 also significantly prolonged the latency of rebound depolarization without spike from 71.9∓35.1 ms to 267.0∓68.8 ms (P<0.05). The T-type calcium channel blockers NiCl2 and mibefradil strongly decreased the amplitude of rebound depolarization with spike from 19.9∓6.3 mV to 9.5∓4.5 mV (P<0.05) and from 26.1∓9.4 mV to 15.5∓5.0 mV (P<0.05), respectively. Mibefradil also significantly decreased the amplitude of rebound depolarization without spike from 14.3∓3.0 mV to 7.9∓2.0 mV (P<0.05). CONCLUSION Nearly two-thirds of the SG neurons have rebound depolarizations modulated by HCN channel and T-type calcium channel.
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Affiliation(s)
- 凌超 李
- 南昌大学第一附属医院 疼痛科, 江西 南昌 330006Department of Pain Clinic
| | - 达颖 张
- 南昌大学第一附属医院 疼痛科, 江西 南昌 330006Department of Pain Clinic
| | - 斯聪 彭
- 南昌大学第一附属医院 儿科, 江西 南昌 330006Department of Pediatrics
| | - 静 吴
- 南昌大学第一附属医院 儿科, 江西 南昌 330006Department of Pediatrics
| | - 昌宇 蒋
- 深圳市南山医院韩济生院士疼痛医学工作站, 广东 深圳 518052Jisheng Han Academician Workstation for Pain Medicine, Nanshan Hosptal, Shenzhen 518052, China
| | - 涛 柳
- 南昌大学第一附属医院 儿科, 江西 南昌 330006Department of Pediatrics
- 南昌大学第一附属医院 医学科研中心, 江西 南昌 330006Center for Experimental Medicine, First Affiliated Hospital of Nanchang University, Nanchang, 330006, China
- 深圳市南山医院韩济生院士疼痛医学工作站, 广东 深圳 518052Jisheng Han Academician Workstation for Pain Medicine, Nanshan Hosptal, Shenzhen 518052, China
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Sodium salicylate potentiates the GABAB-GIRK pathway to suppress rebound depolarization in neurons of the rat's medial geniculate body. Hear Res 2015; 332:104-112. [PMID: 26688177 DOI: 10.1016/j.heares.2015.11.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 11/16/2015] [Accepted: 11/23/2015] [Indexed: 12/15/2022]
Abstract
Rebound depolarization (RD) is a voltage response to the offset from pre-hyperpolarization of neuronal membrane potential, which manifests a particular form of the postsynaptic membrane potential response to inhibitory presynaptic inputs. We previously demonstrated that sodium salicylate (NaSal), a tinnitus inducer, can drastically suppress the RD in neurons of rat medial geniculate body (MGB) (Su et al, 2012; PLoS ONE 7, e46969). The purpose of the present study was to investigate the underlying cellular mechanism by using whole-cell patch-clamp recordings in rat MGB slices. NaSal (1.4 mM) had no effects on the current mediated by T-type Ca(2+) channels, indicating that it does not target these channels to suppress the RD. Instead, NaSal was shown to hyperpolarize the resting membrane potential to suppress the RD. NaSal had no effects on the current mediated by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, indicating that it does not target these channels to hyperpolarize the resting membrane potential. NaSal induced an outward leak current that could be abolished by CGP55845, a GABAB receptor blocker, or respectively by Ba(2+) and Tertiapin-Q, blockers for G-protein-gated inwardly rectifying potassium (GIRK) channels, indicating that NaSal potentiates the GABAB-GIRK pathway to hyperpolarize the resting membrane potential. Our study demonstrates that NaSal targets GABAB receptors to alter functional behaviors of MGB neurons, which may be implicated in NaSal-induced tinnitus.
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