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Rahimi S, Salami P, Matulewicz P, Schmuck A, Bukovac A, Ramos-Prats A, Tasan RO, Drexel M. The role of subicular VIP-expressing interneurons on seizure dynamics in the intrahippocampal kainic acid model of temporal lobe epilepsy. Exp Neurol 2023; 370:114580. [PMID: 37884187 DOI: 10.1016/j.expneurol.2023.114580] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/10/2023] [Accepted: 10/21/2023] [Indexed: 10/28/2023]
Abstract
The subiculum, a key output region of the hippocampus, is increasingly recognized as playing a crucial role in seizure initiation and spread. The subiculum consists of glutamatergic pyramidal cells, which show alterations in intrinsic excitability in the course of epilepsy, and multiple types of GABAergic interneurons, which exhibit varying characteristics in epilepsy. In this study, we aimed to assess the role of the vasoactive intestinal peptide interneurons (VIP-INs) of the ventral subiculum in the pathophysiology of temporal lobe epilepsy. We observed that an anatomically restricted inhibition of VIP-INs of the ventral subiculum was sufficient to reduce seizures in the intrahippocampal kainic acid model of epilepsy, changing the circadian rhythm of seizures, emphasizing the critical role of this small cell population in modulating TLE. As we expected, permanent unilateral or bilateral silencing of VIP-INs of the ventral subiculum in non-epileptic animals did not induce seizures or epileptiform activity. Interestingly, transient activation of VIP-INs of the ventral subiculum was enough to increase the frequency of seizures in the acute seizure model. Our results offer new perspectives on the crucial involvement of VIP-INs of the ventral subiculum in the pathophysiology of TLE. Given the observed predominant disinhibitory role of the VIP-INs input in subicular microcircuits, modifications of this input could be considered in the development of therapeutic strategies to improve seizure control.
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Affiliation(s)
- Sadegh Rahimi
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Pariya Salami
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Pawel Matulewicz
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Armin Schmuck
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Anneliese Bukovac
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Arnau Ramos-Prats
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Ramon Osman Tasan
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Meinrad Drexel
- Department of Pharmacology, Medical University of Innsbruck, Innsbruck, Austria.
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Zhao J, Yu Y, Han F, Wang Q. Regulating epileptiform discharges by heterogeneous interneurons in thalamocortical model. CHAOS (WOODBURY, N.Y.) 2023; 33:083128. [PMID: 37561121 DOI: 10.1063/5.0163243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/25/2023] [Indexed: 08/11/2023]
Abstract
Inhibitory interneurons in the cortex are abundant and have diverse roles, classified as parvalbumin (PV), somatostatin (SOM), and vasoactive intestinal polypeptide (VIP) according to chemically defined categories. Currently, their involvement with seizures has been partially uncovered in physiological terms. Here, we propose a corticothalamic model containing heterogeneous interneurons to study the effects of various interneurons on absence seizure dynamics by means of optogenetic stimulation. First, the important role of feedforward inhibition caused by SRN→PV→PN projections on seizures is verified. Then, we demonstrate that light activation targeting either PV or SOM INs can control seizures. Finally, with different inhibition contributions from PV INs and SOM INs, the possible disinhibitory effect of blue light acting on VIP INs is mainly discussed. The results suggest that depending on the inhibition degree of both types, the disinhibition brought about by the VIP INs will trigger seizures, will control seizures, and will not work or cause the PNs to tend toward a high saturation state with high excitability. The circuit mechanism and the related bifurcation characteristics in various cases are emphatically revealed. In the model presented, in addition to Hopf and saddle-node bifurcations, the system may also undergo period-doubling and torus bifurcations under stimulus action, with more complex dynamics. Our work may provide a theoretical basis for understanding and further exploring the role of heterogeneous interneurons, in particular, the VIP INs, a novel target, in absence seizures.
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Affiliation(s)
- Jinyi Zhao
- Department of Dynamics and Control, Beihang University, Beijing 100191, China
| | - Ying Yu
- School of Engineering Medicine, Beihang University, Beijing 100191, China
| | - Fang Han
- College of Information Science and Technology, Donghua University, Shanghai 201620, China
| | - Qingyun Wang
- Department of Dynamics and Control, Beihang University, Beijing 100191, China
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Köksal Ersöz E, Lazazzera R, Yochum M, Merlet I, Makhalova J, Mercadal B, Sanchez-Todo R, Ruffini G, Bartolomei F, Benquet P, Wendling F. Signal processing and computational modeling for interpretation of SEEG-recorded interictal epileptiform discharges in epileptogenic and non-epileptogenic zones. J Neural Eng 2022; 19. [PMID: 36067727 DOI: 10.1088/1741-2552/ac8fb4] [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: 04/30/2022] [Accepted: 09/06/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE In partial epilepsies, interictal epileptiform discharges (IEDs) are paroxysmal events observed in epileptogenic and non-epileptogenic zones. IEDs' generation and recurrence are subject to different hypotheses: they appear through glutamatergic and GABAergic processes; they may trigger seizures or prevent seizure propagation. This paper focuses on a specific class of IEDs, spike-waves (SWs), characterized by a short-duration spike followed by a longer duration wave, both of the same polarity. Signal analysis and neurophysiological mathematical models are used to interpret puzzling IED generation. APPROACH Interictal activity was recorded by intracranial stereo-electroencephalography (SEEG) electrodes in five different patients. SEEG experts identified the epileptic and non-epileptic zones in which IEDs were detected. After quantifying spatial and temporal features of the detected IEDs, the most significant features for classifying epileptic and non-epileptic zones were determined. A neurophysiologically-plausible mathematical model was then introduced to simulate the IEDs and understand the underlying differences observed in epileptic and non-epileptic zone IEDs. MAIN RESULTS Two classes of SWs were identified according to subtle differences in morphology and timing of the spike and wave component. Results showed that type-1 SWs were generated in epileptogenic regions also involved at seizure onset, while type-2 SWs were produced in the propagation or non-involved areas. The modeling study indicated that synaptic kinetics, cortical organization, and network interactions determined the morphology of the simulated SEEG signals. Modeling results suggested that the IED morphologies were linked to the degree of preserved inhibition. SIGNIFICANCE This work contributes to the understanding of different mechanisms generating IEDs in epileptic networks. The combination of signal analysis and computational models provides an efficient framework for exploring IEDs in partial epilepsies and classifying epileptogenic and non-epileptogenic zones.
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Affiliation(s)
- Elif Köksal Ersöz
- INSERM, LTSI - UMR 1099, Universite de Rennes 1, Campus de Beaulieu, Rennes, Bretagne, 35042 , FRANCE
| | - Remo Lazazzera
- INSERM, LTSI - UMR 1099, Universite de Rennes 1, Campus de Beaulieu, Rennes, Bretagne, 35042 , FRANCE
| | - Maxime Yochum
- INSERM, LTSI - UMR 1099, Universite de Rennes 1, Campus de Beaulieu, Rennes, Bretagne, 35042 , FRANCE
| | - Isabelle Merlet
- INSERM, LTSI - UMR 1099, Universite de Rennes 1, Campus de Beaulieu, Rennes, Bretagne, 35042 , FRANCE
| | - Julia Makhalova
- Neurophysiologie clinique, Service d'Epileptologie et de Rythmologie Cerebrale, Assistance Publique Hopitaux de Marseille, Hôpital de la Timone, Marseille, Provence-Alpes-Côte d'Azu, 13354, FRANCE
| | - Borja Mercadal
- Neuroelectrics Barcelona SL, Av. Tibidabo, 47b, Barcelona, 08035, SPAIN
| | - Roser Sanchez-Todo
- Neuroelectrics Barcelona SL, Avda Tibidabo, 47 bis, Barcelona, Catalunya, 08035, SPAIN
| | - Giulio Ruffini
- Neuroelectrics Barcelona SL, Av. Tibidabo, 47b, Barcelona, Catalunya, 08035, SPAIN
| | - Fabrice Bartolomei
- Neurophysiologie clinique, Service d'Epileptologie et de Rythmologie Cerebrale, Assistance Publique Hopitaux de Marseille, Hôpital de la Timone, Marseille, Provence-Alpes-Côte d'Azu, 13354, FRANCE
| | - Pascal Benquet
- INSERM, LTSI - UMR 1099, Universite de Rennes 1, Campus de Beaulieu, Rennes, Bretagne, 35042 , FRANCE
| | - Fabrice Wendling
- INSERM, LTSI - UMR 1099, Universite de Rennes 1, Campus Beaulieu, Rennes, Bretagne, 35042, FRANCE
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Korkmaz OT, Arkan S, Öncü-Kaya EM, Ateş N, Tunçel N. Vasoactive intestinal peptide (VIP) conducts the neuronal activity during absence seizures: GABA seems to be the main mediator of VIP. Neurosci Lett 2021; 765:136268. [PMID: 34571088 DOI: 10.1016/j.neulet.2021.136268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 11/27/2022]
Abstract
Absence epilepsy is classified as a childhood generalized epilepsy syndrome with distinctive electroencephalographic patterns. The Wistar Albino Glaxo originating from Rijswijk (WAG/Rij) strain is a very well validated animal model of absence epilepsy that also shows behavioral deficits. In addition to the gastrointestinal system, VIP is highly expressed throughout numerous brain regions, and it plays crucial roles as a neurotransmitter and as a neuromodulatory, neurotrophic and neuroprotective factor in both the central and peripheral nervous systems. In this study, adult WAG/Rij rats were divided into two groups (n = 10): a group that was administered VIP (25 ng/kg i.p.) every 2 days for 15 days and an age-matched control group that was administered physiological saline. Electrical brain activity and behavior (depressive- like behavior, learning and memory and anxiety) were investigated in both groups. In addition, the extracellular concentrations of GABA and glutamate and the GABA/glutamate ratio were measured by high-performance liquid chromatography in microdialysate samples collected from the somatosensorial cortex of WAG/Rij rats. Our results demonstrated that VIP treatment significantly suppressed the total duration and number of spike wave discharges in WAG/Rij rats. However, VIP had no significant effect on behavior. VIP increased the extracellular concentration of GABA and the GABA/glutamate ratio in the somatosensory cortex. In conclusion, VIP has suppressive effects on absence seizures, possibly by increasing the GABA concentration and inducing the transformation of glutamate to GABA in the somatosensory cortex of WAG/Rij rats.
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Affiliation(s)
- Orhan Tansel Korkmaz
- Department of Physiology, Faculty of Medicine, Eskisehir Osmangazi University, 26040 Eskisehir, Turkey.
| | - Sertan Arkan
- Department of Physiology, Medical Faculty, Kocaeli University, 41380, Kocaeli, Turkey
| | - Elif Mine Öncü-Kaya
- Department of Chemistry, Science Faculty, Eskisehir Technical University, 26470 Eskisehir, Turkey
| | - Nurbay Ateş
- Department of Physiology, Medical Faculty, Kocaeli University, 41380, Kocaeli, Turkey
| | - Neşe Tunçel
- Department of Physiology, Faculty of Medicine, Eskisehir Osmangazi University, 26040 Eskisehir, Turkey
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Traub RD, Moeller F, Rosch R, Baldeweg T, Whittington MA, Hall SP. Seizure initiation in infantile spasms vs. focal seizures: proposed common cellular mechanisms. Rev Neurosci 2020; 31:181-200. [PMID: 31525161 DOI: 10.1515/revneuro-2019-0030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/01/2019] [Indexed: 11/15/2022]
Abstract
Infantile spasms (IS) and seizures with focal onset have different clinical expressions, even when electroencephalography (EEG) associated with IS has some degree of focality. Oddly, identical pathology (with, however, age-dependent expression) can lead to IS in one patient vs. focal seizures in another or even in the same, albeit older, patient. We therefore investigated whether the cellular mechanisms underlying seizure initiation are similar in the two instances: spasms vs. focal. We noted that in-common EEG features can include (i) a background of waves at alpha to delta frequencies; (ii) a period of flattening, lasting about a second or more - the electrodecrement (ED); and (iii) often an interval of very fast oscillations (VFO; ~70 Hz or faster) preceding, or at the beginning of, the ED. With IS, VFO temporally coincides with the motor spasm. What is different between the two conditions is this: with IS, the ED reverts to recurring slow waves, as occurring before the ED, whereas with focal seizures the ED instead evolves into an electrographic seizure, containing high-amplitude synchronized bursts, having superimposed VFO. We used in vitro data to help understand these patterns, as such data suggest cellular mechanisms for delta waves, for VFO, for seizure-related burst complexes containing VFO, and, more recently, for the ED. We propose a unifying mechanistic hypothesis - emphasizing the importance of brain pH - to explain the commonalities and differences of EEG signals in IS versus focal seizures.
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Affiliation(s)
- Roger D Traub
- IBM Thomas J. Watson Research Center, Yorktown Heights, NY 10598, USA
- Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Friederike Moeller
- Department of Clinical Neurophysiology, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Richard Rosch
- MRC Centre for Neurodevelopmental Disorders, King's College London, New Hunt's House, London SE1 1UL, UK
| | - Torsten Baldeweg
- Institute of Child Health, University College London, 30 Guildford Street, London WC1N 1EH, UK
| | | | - Stephen P Hall
- Hull York Medical School, University of York, Heslington YO10 5DD, UK
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Aeed F, Shnitzer T, Talmon R, Schiller Y. Layer- and Cell-Specific Recruitment Dynamics during Epileptic Seizures In Vivo. Ann Neurol 2019; 87:97-115. [PMID: 31657482 DOI: 10.1002/ana.25628] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To investigate the network dynamics mechanisms underlying differential initiation of epileptic interictal spikes and seizures. METHODS We performed combined in vivo 2-photon calcium imaging from different targeted neuronal subpopulations and extracellular electrophysiological recordings during 4-aminopyridine-induced neocortical spikes and seizures. RESULTS Both spikes and seizures were associated with intense synchronized activation of excitatory layer 2/3 pyramidal neurons (PNs) and to a lesser degree layer 4 neurons, as well as inhibitory parvalbumin-expressing interneurons (INs). In sharp contrast, layer 5 PNs and somatostatin-expressing INs were gradually and asynchronously recruited into the ictal activity during the course of seizures. Within layer 2/3, the main difference between onset of spikes and seizures lay in the relative recruitment dynamics of excitatory PNs compared to parvalbumin- and somatostatin-expressing inhibitory INs. Whereas spikes exhibited balanced recruitment of PNs and parvalbumin-expressing INs, during seizures IN responses were reduced and less synchronized than in layer 2/3 PNs. Similar imbalance was not observed in layers 4 or 5 of the neocortex. Machine learning-based algorithms we developed were able to distinguish spikes from seizures based solely on activation dynamics of layer 2/3 PNs at discharge onset. INTERPRETATION During onset of seizures, the recruitment dynamics markedly differed between neuronal subpopulations, with rapid synchronous recruitment of layer 2/3 PNs, layer 4 neurons, and parvalbumin-expressing INs and gradual asynchronous recruitment of layer 5 PNs and somatostatin-expressing INs. Seizures initiated in layer 2/3 due to a dynamic mismatch between local PNs and inhibitory INs, and only later spread to layer 5 by gradually and asynchronously recruiting PNs in this layer. ANN NEUROL 2020;87:97-115.
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Affiliation(s)
- Fadi Aeed
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Tal Shnitzer
- Viterbi Faculty of Electrical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ronen Talmon
- Viterbi Faculty of Electrical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yitzhak Schiller
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.,Department of Neurology, Rambam Medical Center, Haifa, Israel
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7
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Wei L, He F, Zhang W, Chen W, Yu B. Bioinformatics analysis of microarray data to reveal the pathogenesis of diffuse intrinsic pontine glioma. Biol Res 2018; 51:26. [PMID: 30124166 PMCID: PMC6100713 DOI: 10.1186/s40659-018-0175-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 08/12/2018] [Indexed: 12/27/2022] Open
Abstract
Background Diffuse intrinsic pontine glioma (DIPG) is the main cause of pediatric brain tumor death. This study was designed to identify key genes associated with DIPG. Methods The gene expression profile GSE50021, which consisted of 35 pediatric DIPG samples and 10 normal brain samples, was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified by limma package. Functional and pathway enrichment analyses were performed by the DAVID tool. Protein–protein interaction (PPI) network, and transcription factor (TF)–microRNA (miRNA)–target gene network were constructed using Cytoscape. Moreover, the expression levels of several genes were validated in human glioma cell line U251 and normal glia HEB cells through real-time polymerase chain reaction (PCR). Results A total of 378 DEGs were screened (74 up-regulated and 304 down-regulated genes). In the PPI network, GRM1, HTR2A, GRM7 and GRM2 had higher degrees. Besides, GRM1 and HTR2A were significantly enriched in the neuroactive ligand–receptor interaction pathway, and calcium signaling pathway. In addition, TFAP2C was a significant down-regulated functional gene and hsa-miR-26b-5p had a higher degree in the TF-miRNA-target gene network. PCR analysis revealed that GRM7 and HTR2A were significantly downregulated while TFAP2C was upregulated in U251 cells compared with that in HEB cells (p < 0.001). GRM2 was not detected in cells. Conclusions GRM1 and HTR2A might function in DIPG through the neuroactive ligand–receptor interaction pathway and the calcium signaling pathway. Furthermore, the TFAP2C and hsa-miR-26b-5p might play important roles in the development and progression mechanisms of DIPG.
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Affiliation(s)
- Li Wei
- Department of Rehabilitation, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100, Haining Road, Shanghai, 200080, China
| | - Fei He
- Department of Rehabilitation, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100, Haining Road, Shanghai, 200080, China
| | - Wen Zhang
- Department of Rehabilitation, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100, Haining Road, Shanghai, 200080, China
| | - Wenhua Chen
- Department of Rehabilitation, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100, Haining Road, Shanghai, 200080, China.,School of International Medical Technology, Shanghai Sanda University, No. 2727, Jinhai Road, Shanghai, 201209, China
| | - Bo Yu
- Department of Rehabilitation, Shanghai General Hospital, Shanghai Jiao Tong University, No. 100, Haining Road, Shanghai, 200080, China. .,School of International Medical Technology, Shanghai Sanda University, No. 2727, Jinhai Road, Shanghai, 201209, China.
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8
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Jackson J, Karnani MM, Zemelman BV, Burdakov D, Lee AK. Inhibitory Control of Prefrontal Cortex by the Claustrum. Neuron 2018; 99:1029-1039.e4. [PMID: 30122374 PMCID: PMC6168643 DOI: 10.1016/j.neuron.2018.07.031] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 06/17/2018] [Accepted: 07/18/2018] [Indexed: 11/21/2022]
Abstract
The claustrum is a small subcortical nucleus that has extensive excitatory connections with many cortical areas. While the anatomical connectivity from the claustrum to the cortex has been studied intensively, the physiological effect and underlying circuit mechanisms of claustrocortical communication remain elusive. Here we show that the claustrum provides strong, widespread, and long-lasting feedforward inhibition of the prefrontal cortex (PFC) sufficient to silence ongoing neural activity. This claustrocortical feedforward inhibition was predominantly mediated by interneurons containing neuropeptide Y, and to a lesser extent those containing parvalbumin. Therefore, in contrast to other long-range excitatory inputs to the PFC, the claustrocortical pathway is designed to provide overall inhibition of cortical activity. This unique circuit organization allows the claustrum to rapidly and powerfully suppress cortical networks and suggests a distinct role for the claustrum in regulating cognitive processes in prefrontal circuits. The claustrum strongly inhibits, rather than excites, prefrontal cortex Prefrontal NPY and PV interneurons are activated by the claustrum Claustrocortical feedforward inhibition is predominantly mediated by NPY neurons
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Affiliation(s)
- Jesse Jackson
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA; Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| | | | - Boris V Zemelman
- Department of Neuroscience, Center for Learning and Memory, University of Texas, University Station, C7000 Austin, TX 78712, USA
| | - Denis Burdakov
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Albert K Lee
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA.
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Hall SP, Traub RD, Adams NE, Cunningham MO, Schofield I, Jenkins AJ, Whittington MA. Enhanced interlaminar excitation or reduced superficial layer inhibition in neocortex generates different spike-and-wave-like electrographic events in vitro. J Neurophysiol 2018; 119:49-61. [PMID: 28954894 PMCID: PMC5866469 DOI: 10.1152/jn.00516.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/26/2017] [Accepted: 09/26/2017] [Indexed: 12/19/2022] Open
Abstract
Acute in vitro models have revealed a great deal of information about mechanisms underlying many types of epileptiform activity. However, few examples exist that shed light on spike-and-wave (SpW) patterns of pathological activity. SpW are seen in many epilepsy syndromes, both generalized and focal, and manifest across the entire age spectrum. They are heterogeneous in terms of their severity, symptom burden, and apparent anatomical origin (thalamic, neocortical, or both), but any relationship between this heterogeneity and underlying pathology remains elusive. In this study we demonstrate that physiological delta-frequency rhythms act as an effective substrate to permit modeling of SpW of cortical origin and may help to address this issue. For a starting point of delta activity, multiple subtypes of SpW could be modeled computationally and experimentally by either enhancing the magnitude of excitatory synaptic events ascending from neocortical layer 5 to layers 2/3 or selectively modifying superficial layer GABAergic inhibition. The former generated SpW containing multiple field spikes with long interspike intervals, whereas the latter generated SpW with short-interval multiple field spikes. Both types had different laminar origins and each disrupted interlaminar cortical dynamics in a different manner. A small number of examples of human recordings from patients with different diagnoses revealed SpW subtypes with the same temporal signatures, suggesting that detailed quantification of the pattern of spikes in SpW discharges may be a useful indicator of disparate underlying epileptogenic pathologies. NEW & NOTEWORTHY Spike-and-wave-type discharges (SpW) are a common feature in many epilepsies. Their electrographic manifestation is highly varied, as are available genetic clues to associated underlying pathology. Using computational and in vitro models, we demonstrate that distinct subtypes of SpW are generated by lamina-selective disinhibition or enhanced interlaminar excitation. These subtypes could be detected in at least some noninvasive patient recordings, suggesting more detailed analysis of SpW may be useful in determining clinical pathology.
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Affiliation(s)
- Stephen P Hall
- Hull York Medical School, University of York , Heslington , United Kingdom
| | - Roger D Traub
- Department of Physical Sciences, IBM Thomas J. Watson Research Center , Yorktown Heights, New York
| | - Natalie E Adams
- Hull York Medical School, University of York , Heslington , United Kingdom
| | - Mark O Cunningham
- Institute of Neuroscience, Newcastle University , Newcastle upon Tyne , United Kingdom
| | - Ian Schofield
- Department of Clinical Neurophysiology, Royal Victoria Infirmary, Newcastle upon Tyne , United Kingdom
| | - Alistair J Jenkins
- Department of Clinical Neurophysiology, Royal Victoria Infirmary, Newcastle upon Tyne , United Kingdom
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Traub RD, Whittington MA, Hall SP. Does Epileptiform Activity Represent a Failure of Neuromodulation to Control Central Pattern Generator-Like Neocortical Behavior? Front Neural Circuits 2017; 11:78. [PMID: 29093667 PMCID: PMC5651241 DOI: 10.3389/fncir.2017.00078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/04/2017] [Indexed: 12/22/2022] Open
Abstract
Rhythmic motor patterns in invertebrates are often driven by specialized “central pattern generators” (CPGs), containing small numbers of neurons, which are likely to be “identifiable” in one individual compared with another. The dynamics of any particular CPG lies under the control of modulatory substances, amines, or peptides, entering the CPG from outside it, or released by internal constituent neurons; consequently, a particular CPG can generate a given rhythm at different frequencies and amplitudes, and perhaps even generate a repertoire of distinctive patterns. The mechanisms exploited by neuromodulators in this respect are manifold: Intrinsic conductances (e.g., calcium, potassium channels), conductance state of postsynaptic receptors, degree of plasticity, and magnitude and kinetics of transmitter release can all be affected. The CPG concept has been generalized to vertebrate motor pattern generating circuits (e.g., for locomotion), which may contain large numbers of neurons – a construct that is sensible, if there is enough redundancy: that is, the large number of neurons consists of only a small number of classes, and the cells within any one class act stereotypically. Here we suggest that CPG and modulator ideas may also help to understand cortical oscillations, normal ones, and particularly transition to epileptiform pathology. Furthermore, in the case illustrated, the mechanism of the transition appears to be an exaggerated form of a normal modulatory action used to influence sensory processing.
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Affiliation(s)
- Roger D Traub
- Department of Physical Sciences, IBM Thomas J. Watson Research Center, New York City, NY, United States
| | - Miles A Whittington
- Department of Biology, Hull York Medical School, University of York, York, United Kingdom
| | - Stephen P Hall
- Department of Biology, Hull York Medical School, University of York, York, United Kingdom
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11
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Aberrant Network Activity in Schizophrenia. Trends Neurosci 2017; 40:371-382. [PMID: 28515010 DOI: 10.1016/j.tins.2017.04.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 12/25/2022]
Abstract
Brain dynamic changes associated with schizophrenia are largely equivocal, with interpretation complicated by many factors, such as the presence of therapeutic agents and the complex nature of the syndrome itself. Evidence for a brain-wide change in individual network oscillations, shared by all patients, is largely equivocal, but stronger for lower (delta) than for higher (gamma) bands. However, region-specific changes in rhythms across multiple, interdependent, nested frequencies may correlate better with pathology. Changes in synaptic excitation and inhibition in schizophrenia disrupt delta rhythm-mediated cortico-cortical communication, while enhancing thalamocortical communication in this frequency band. The contrasting relationships between delta and higher frequencies in thalamus and cortex generate frequency mismatches in inter-regional connectivity, leading to a disruption in temporal communication between higher-order brain regions associated with mental time travel.
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Khoshkhoo S, Vogt D, Sohal VS. Dynamic, Cell-Type-Specific Roles for GABAergic Interneurons in a Mouse Model of Optogenetically Inducible Seizures. Neuron 2016; 93:291-298. [PMID: 28041880 DOI: 10.1016/j.neuron.2016.11.043] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 08/05/2016] [Accepted: 11/16/2016] [Indexed: 01/19/2023]
Abstract
GABAergic interneurons play critical roles in seizures, but it remains unknown whether these vary across interneuron subtypes or evolve during a seizure. This uncertainty stems from the unpredictable timing of seizures in most models, which limits neuronal imaging or manipulations around the seizure onset. Here, we describe a mouse model for optogenetic seizure induction. Combining this with calcium imaging, we find that seizure onset rapidly recruits parvalbumin (PV), somatostatin (SOM), and vasoactive intestinal peptitde (VIP)-expressing interneurons, whereas excitatory neurons are recruited several seconds later. Optogenetically inhibiting VIP interneurons consistently increased seizure threshold and reduced seizure duration. Inhibiting PV+ and SOM+ interneurons had mixed effects on seizure initiation but consistently reduced seizure duration. Thus, while their roles may evolve during seizures, PV+ and SOM+ interneurons ultimately help maintain ongoing seizures. These results show how an optogenetically induced seizure model can be leveraged to pinpoint a new target for seizure control: VIP interneurons. VIDEO ABSTRACT.
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Affiliation(s)
- Sattar Khoshkhoo
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA
| | - Daniel Vogt
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA
| | - Vikaas S Sohal
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA.
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Judson MC, Wallace ML, Sidorov MS, Burette AC, Gu B, van Woerden GM, King IF, Han JE, Zylka MJ, Elgersma Y, Weinberg RJ, Philpot BD. GABAergic Neuron-Specific Loss of Ube3a Causes Angelman Syndrome-Like EEG Abnormalities and Enhances Seizure Susceptibility. Neuron 2016; 90:56-69. [PMID: 27021170 DOI: 10.1016/j.neuron.2016.02.040] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 01/17/2016] [Accepted: 02/24/2016] [Indexed: 11/19/2022]
Abstract
Loss of maternal UBE3A causes Angelman syndrome (AS), a neurodevelopmental disorder associated with severe epilepsy. We previously implicated GABAergic deficits onto layer (L) 2/3 pyramidal neurons in the pathogenesis of neocortical hyperexcitability, and perhaps epilepsy, in AS model mice. Here we investigate consequences of selective Ube3a loss from either GABAergic or glutamatergic neurons, focusing on the development of hyperexcitability within L2/3 neocortex and in broader circuit and behavioral contexts. We find that GABAergic Ube3a loss causes AS-like increases in neocortical EEG delta power, enhances seizure susceptibility, and leads to presynaptic accumulation of clathrin-coated vesicles (CCVs)-all without decreasing GABAergic inhibition onto L2/3 pyramidal neurons. Conversely, glutamatergic Ube3a loss fails to yield EEG abnormalities, seizures, or associated CCV phenotypes, despite impairing tonic inhibition onto L2/3 pyramidal neurons. These results substantiate GABAergic Ube3a loss as the principal cause of circuit hyperexcitability in AS mice, lending insight into ictogenic mechanisms in AS.
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Affiliation(s)
- Matthew C Judson
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Michael L Wallace
- Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA; Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Michael S Sidorov
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Alain C Burette
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Bin Gu
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Geeske M van Woerden
- Department of Neuroscience, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands; ENCORE Center for Neurodevelopmental Disorders, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - Ian F King
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ji Eun Han
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Mark J Zylka
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA; Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ype Elgersma
- Department of Neuroscience, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands; ENCORE Center for Neurodevelopmental Disorders, Erasmus Medical Center, Wytemaweg 80, 3015 CN Rotterdam, the Netherlands
| | - Richard J Weinberg
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Benjamin D Philpot
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA; Curriculum in Neurobiology, University of North Carolina, Chapel Hill, NC 27599, USA; Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA.
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