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Yang D, Qi G, Ort J, Witzig V, Bak A, Delev D, Koch H, Feldmeyer D. Modulation of large rhythmic depolarizations in human large basket cells by norepinephrine and acetylcholine. Commun Biol 2024; 7:885. [PMID: 39033173 PMCID: PMC11271271 DOI: 10.1038/s42003-024-06546-2] [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: 04/13/2024] [Accepted: 07/03/2024] [Indexed: 07/23/2024] Open
Abstract
Rhythmic brain activity is critical to many brain functions and is sensitive to neuromodulation, but so far very few studies have investigated this activity on the cellular level in vitro in human brain tissue samples. This study reveals and characterizes a novel rhythmic network activity in the human neocortex. Using intracellular patch-clamp recordings of human cortical neurons, we identify large rhythmic depolarizations (LRDs) driven by glutamate release but not by GABA. These LRDs are intricate events made up of multiple depolarizing phases, occurring at ~0.3 Hz, have large amplitudes and long decay times. Unlike human tissue, rat neocortex layers 2/3 exhibit no such activity under identical conditions. LRDs are mainly observed in a subset of L2/3 interneurons that receive substantial excitatory inputs and are likely large basket cells based on their morphology. LRDs are highly sensitive to norepinephrine (NE) and acetylcholine (ACh), two neuromodulators that affect network dynamics. NE increases LRD frequency through β-adrenergic receptor activity while ACh decreases it via M4 muscarinic receptor activation. Multi-electrode array recordings show that NE enhances and synchronizes oscillatory network activity, whereas ACh causes desynchronization. Thus, NE and ACh distinctly modulate LRDs, exerting specific control over human neocortical activity.
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Affiliation(s)
- Danqing Yang
- Research Center Juelich, Institute of Neuroscience and Medicine 10, Research Center Juelich, 52425, Juelich, Germany
- Department of Psychiatry, Psychotherapy, and Psychosomatics, RWTH Aachen University Hospital, 52074, Aachen, Germany
| | - Guanxiao Qi
- Research Center Juelich, Institute of Neuroscience and Medicine 10, Research Center Juelich, 52425, Juelich, Germany
| | - Jonas Ort
- Department of Neurosurgery, Faculty of Medicine, RWTH Aachen University Hospital, Aachen, Germany
- Neurosurgical Artificial Intelligence Laboratory Aachen (NAILA), RWTH Aachen University Hospital, 52074, Aachen, Germany
- Center for Integrated Oncology, Universities Aachen, Bonn, Cologne, Düsseldorf (CIO ABCD), Bonn, Germany
| | - Victoria Witzig
- Department of Neurology, RWTH Aachen University Hospital, 52074, Aachen, Germany
| | - Aniella Bak
- Department of Neurology, Section Epileptology, RWTH Aachen University Hospital, 52074, Aachen, Germany
| | - Daniel Delev
- Department of Neurosurgery, Faculty of Medicine, RWTH Aachen University Hospital, Aachen, Germany
- Neurosurgical Artificial Intelligence Laboratory Aachen (NAILA), RWTH Aachen University Hospital, 52074, Aachen, Germany
- Center for Integrated Oncology, Universities Aachen, Bonn, Cologne, Düsseldorf (CIO ABCD), Bonn, Germany
| | - Henner Koch
- Department of Neurology, Section Epileptology, RWTH Aachen University Hospital, 52074, Aachen, Germany
| | - Dirk Feldmeyer
- Research Center Juelich, Institute of Neuroscience and Medicine 10, Research Center Juelich, 52425, Juelich, Germany.
- Department of Psychiatry, Psychotherapy, and Psychosomatics, RWTH Aachen University Hospital, 52074, Aachen, Germany.
- Jülich-Aachen Research Alliance, Translational Brain Medicine (JARA Brain), Aachen, Germany.
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Landry CR, Yip MC, Zhou Y, Niu W, Wang Y, Yang B, Wen Z, Forest CR. Electrophysiological and morphological characterization of single neurons in intact human brain organoids. J Neurosci Methods 2023; 394:109898. [PMID: 37236404 PMCID: PMC10483933 DOI: 10.1016/j.jneumeth.2023.109898] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/12/2023] [Accepted: 05/20/2023] [Indexed: 05/28/2023]
Abstract
Brain organoids represent a new model system for studying developmental human neurophysiology. Methods for studying the electrophysiology and morphology of single neurons in organoids require acute slices or dissociated cultures. While these methods have advantages (e.g., visual access, ease of experimentation), they risk damaging cells and circuits present in the intact organoid. To access single cells within intact organoid circuits, we have demonstrated a method for fixturing and performing whole cell patch clamp recording from intact brain organoids using both manual and automated tools. We demonstrate applied electrophysiology methods development followed by an integration of electrophysiology with reconstructing the morphology of the neurons within the brain organoid using dye filling and tissue clearing. We found that whole cell patch clamp recordings could be achieved both on the surface and within the interior of intact human brain organoids using both manual and automated methods. Manual experiments were higher yield (53 % whole cell success rate manual, 9 % whole cell success rate automated), but automated experiments were more efficient (30 patch attempts per day automated, 10 patch attempts per day manual). Using these methods, we performed an unbiased survey of cells within human brain organoids between 90 and 120 days in vitro (DIV) and present preliminary data on morphological and electrical diversity in human brain organoids. The further development of intact brain organoid patch clamp methods could be broadly applicable to studies of cellular, synaptic, and circuit-level function in the developing human brain.
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Affiliation(s)
- Corey R Landry
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, United States.
| | - Mighten C Yip
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, United States
| | - Ying Zhou
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, United States
| | - Weibo Niu
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, United States
| | - Yunmiao Wang
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, United States; Department of Biology, Emory University, United States
| | - Bo Yang
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, United States
| | - Zhexing Wen
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, United States; Department of Cell Biology, Emory University School of Medicine, United States
| | - Craig R Forest
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, United States; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, United States
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3
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Szegedi V, Bakos E, Furdan S, Kovács BH, Varga D, Erdélyi M, Barzó P, Szücs A, Tamás G, Lamsa K. HCN channels at the cell soma ensure the rapid electrical reactivity of fast-spiking interneurons in human neocortex. PLoS Biol 2023; 21:e3002001. [PMID: 36745683 PMCID: PMC9934405 DOI: 10.1371/journal.pbio.3002001] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 02/16/2023] [Accepted: 01/17/2023] [Indexed: 02/07/2023] Open
Abstract
Accumulating evidence indicates that there are substantial species differences in the properties of mammalian neurons, yet theories on circuit activity and information processing in the human brain are based heavily on results obtained from rodents and other experimental animals. This knowledge gap may be particularly important for understanding the neocortex, the brain area responsible for the most complex neuronal operations and showing the greatest evolutionary divergence. Here, we examined differences in the electrophysiological properties of human and mouse fast-spiking GABAergic basket cells, among the most abundant inhibitory interneurons in cortex. Analyses of membrane potential responses to current input, pharmacologically isolated somatic leak currents, isolated soma outside-out patch recordings, and immunohistochemical staining revealed that human neocortical basket cells abundantly express hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channel isoforms HCN1 and HCN2 at the cell soma membrane, whereas these channels are sparse at the rodent basket cell soma membrane. Antagonist experiments showed that HCN channels in human neurons contribute to the resting membrane potential and cell excitability at the cell soma, accelerate somatic membrane potential kinetics, and shorten the lag between excitatory postsynaptic potentials and action potential generation. These effects are important because the soma of human fast-spiking neurons without HCN channels exhibit low persistent ion leak and slow membrane potential kinetics, compared with mouse fast-spiking neurons. HCN channels speed up human cell membrane potential kinetics and help attain an input-output rate close to that of rodent cells. Computational modeling demonstrated that HCN channel activity at the human fast-spiking cell soma membrane is sufficient to accelerate the input-output function as observed in cell recordings. Thus, human and mouse fast-spiking neurons exhibit functionally significant differences in ion channel composition at the cell soma membrane to set the speed and fidelity of their input-output function. These HCN channels ensure fast electrical reactivity of fast-spiking cells in human neocortex.
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Affiliation(s)
- Viktor Szegedi
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
- Hungarian Centre of Excellence for Molecular Medicine Research Group for Human neuron physiology and therapy, Szeged, Hungary
| | - Emőke Bakos
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
- Hungarian Centre of Excellence for Molecular Medicine Research Group for Human neuron physiology and therapy, Szeged, Hungary
| | - Szabina Furdan
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
- Hungarian Centre of Excellence for Molecular Medicine Research Group for Human neuron physiology and therapy, Szeged, Hungary
| | - Bálint H. Kovács
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - Dániel Varga
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - Miklós Erdélyi
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - Pál Barzó
- Department of Neurosurgery, University of Szeged, Szeged, Hungary
| | - Attila Szücs
- Hungarian Centre of Excellence for Molecular Medicine Research Group for Human neuron physiology and therapy, Szeged, Hungary
- Neuronal Cell Biology Research Group, Eötvös Loránd University, Budapest, Budapest, Hungary
| | - Gábor Tamás
- MTA-SZTE Research Group for Cortical Microcircuits, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Karri Lamsa
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
- Hungarian Centre of Excellence for Molecular Medicine Research Group for Human neuron physiology and therapy, Szeged, Hungary
- * E-mail: ,
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Malkin SL, Khachatryan VA, Fedorov EV, Zaitsev AV. The Electrophysiological Properties of Cortical Neurons in the Epileptic Foci of Children with Refractory Temporal Lobe Epilepsy. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022010197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Neurophysiological Characterization of Posteromedial Hypothalamus in Anaesthetized Patients. Brain Sci 2021; 12:brainsci12010043. [PMID: 35053786 PMCID: PMC8773588 DOI: 10.3390/brainsci12010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/25/2021] [Accepted: 12/27/2021] [Indexed: 11/23/2022] Open
Abstract
Deep brain stimulation (DBS) requires a precise localization, which is especially difficult at the hypothalamus, because it is usually performed in anesthetized patients. We aimed to characterize the neurophysiological properties posteromedial hypothalamus (PMH), identified by the best neurophysiological response to electrical stimulation. We obtained microelectrode recordings from four patients with intractable aggressivity operated under general anesthesia. We pooled data from 1.5 mm at PMH, 1.5 mm upper (uPMH) and 1.5 mm lower (lPMH). We analyzed 178 units, characterized by the mean action potential (mAP). Only 11% were negative. We identified the next types of units: P1N1 (30.9%), N1P1N2 (29.8%), P1P2N1 (16.3%), N1P1 and N1N2P1 (6.2%) and P1N1P2 (5.0%). Besides, atypical action potentials (amAP) were recorded in 11.8%. PMH was highly different in cell composition from uPMH and lPMH, exhibiting also a higher percentage of amAP. Different kinds of cells shared similar features for the three hypothalamic regions. Although features for discharge pattern did not show region specificity, the probability mass function of inter-spike interval were different for all the three regions. Comparison of the same kind of mAP with thalamic neurons previously published demonstrate that most of cells are different for derivatives, amplitude and/or duration of repolarization and depolarization phases and also for the first phase, demonstrating a highly specificity for both brain centers. Therefore, the different properties described for PMH can be used to positively refine targeting, even under general anesthesia. Besides, we describe by first time the presence of atypical extracellular action potentials.
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Features of Action Potentials from Identified Thalamic Nuclei in Anesthetized Patients. Brain Sci 2020; 10:brainsci10121002. [PMID: 33348660 PMCID: PMC7766545 DOI: 10.3390/brainsci10121002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/24/2020] [Accepted: 12/14/2020] [Indexed: 11/23/2022] Open
Abstract
Our objective was to describe the electrophysiological properties of the extracellular action potential (AP) picked up through microelectrode recordings (MERs). Five patients were operated under general anesthesia for centromedian deep brain stimulation (DBS). APs from the same cell were pooled to obtain a mean AP (mAP). The amplitudes and durations for all 2/3 phases were computed from the mAP, together with the maximum (dVmax) and minimum (dVmin) values of the first derivative, as well as the slopes of different phases during repolarization. The mAPs are denominated according to the phase polarity (P/N for positive/negative). We obtained a total of 1109 mAPs, most of the positive (98.47%) and triphasic (93.69%) with a small P/N deflection (Vphase1) before depolarization. The percentage of the different types of mAPs was different for the nuclei addressed. The relationship between dVmax and the depolarizing phase is specific. The descending phase of the first derivative identified different phases during the repolarizing period. We observed a high correlation between Vphase1 and the amplitudes of either depolarization or repolarization phases. Human thalamic nuclei differ in their electrophysiological properties of APs, even under general anesthesia. Capacitive current, which is probably responsible for Vphase1, is very common in thalamic APs. Moreover, subtle differences during repolarization are neuron-specific.
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Kandrács Á, Hofer KT, Tóth K, Tóth EZ, Entz L, Bagó AG, Erőss L, Jordán Z, Nagy G, Fabó D, Ulbert I, Wittner L. Presence of synchrony-generating hubs in the human epileptic neocortex. J Physiol 2019; 597:5639-5670. [PMID: 31523807 DOI: 10.1113/jp278499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/06/2019] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS •Initiation of pathological synchronous events such as epileptic spikes and seizures is linked to the hyperexcitability of the neuronal network in both humans and animals. •In the present study, we show that epileptiform interictal-like spikes and seizures emerged in human neocortical slices by blocking GABAA receptors, following the disappearance of the spontaneously occurring synchronous population activity. •Large variability of temporally and spatially simple and complex spikes was generated by tissue from epileptic patients, whereas only simple events appeared in samples from non-epileptic patients. •Physiological population activity was associated with a moderate level of principal cell and interneuron firing, with a slight dominance of excitatory neuronal activity, whereas epileptiform events were mainly initiated by the synchronous and intense discharge of inhibitory cells. •These results help us to understand the role of excitatory and inhibitory neurons in synchrony-generating mechanisms, in both epileptic and non-epileptic conditions. ABSTRACT Understanding the role of different neuron types in synchrony generation is crucial for developing new therapies aiming to prevent hypersynchronous events such as epileptic seizures. Paroxysmal activity was linked to hyperexcitability and to bursting behaviour of pyramidal cells in animals. Human data suggested a leading role of either principal cells or interneurons, depending on the seizure morphology. In the present study, we aimed to uncover the role of excitatory and inhibitory processes in synchrony generation by analysing the activity of clustered single neurons during physiological and epileptiform synchronies in human neocortical slices. Spontaneous population activity was detected with a 24-channel laminar microelectrode in tissue derived from patients with or without preoperative clinical manifestations of epilepsy. This population activity disappeared by blocking GABAA receptors, and several variations of spatially and temporally simple or complex interictal-like spikes emerged in epileptic tissue, whereas peritumoural slices generated only simple spikes. Around one-half of the clustered neurons participated with an elevated firing rate in physiological synchronies with a slight dominance of excitatory cells. By contrast, more than 90% of the neurons contributed to interictal-like spikes and seizures, and an intense and synchronous discharge of inhibitory neurons was associated with the start of these events. Intrinsically bursting principal cells fired later than other neurons. Our data suggest that a balanced excitation and inhibition characterized physiological synchronies, whereas disinhibition-induced epileptiform events were initiated mainly by non-synaptically synchronized inhibitory neurons. Our results further highlight the differences between humans and animal models, and between in vivo and (pharmacologically manipulated) in vitro conditions.
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Affiliation(s)
- Ágnes Kandrács
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.,Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Katharina T Hofer
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.,Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Kinga Tóth
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Estilla Z Tóth
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - László Entz
- National Institute of Clinical Neuroscience, Budapest, Hungary
| | - Attila G Bagó
- National Institute of Clinical Neuroscience, Budapest, Hungary
| | - Loránd Erőss
- National Institute of Clinical Neuroscience, Budapest, Hungary
| | - Zsófia Jordán
- National Institute of Clinical Neuroscience, Budapest, Hungary
| | - Gábor Nagy
- National Institute of Clinical Neuroscience, Budapest, Hungary
| | - Dániel Fabó
- National Institute of Clinical Neuroscience, Budapest, Hungary
| | - István Ulbert
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.,Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary.,National Institute of Clinical Neuroscience, Budapest, Hungary
| | - Lucia Wittner
- Institute of Cognitive Neuroscience and Psychology, Research Center for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary.,Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary.,National Institute of Clinical Neuroscience, Budapest, Hungary
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8
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Inhibition and oscillations in the human brain tissue in vitro. Neurobiol Dis 2019; 125:198-210. [DOI: 10.1016/j.nbd.2019.02.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/22/2018] [Accepted: 02/07/2019] [Indexed: 01/22/2023] Open
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9
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Abstract
Pathological high-frequency oscillations (HFOs) (80-800 Hz) are considered biomarkers of epileptogenic tissue, but the underlying complex neuronal events are not well understood. Here, we identify and discuss several outstanding issues or conundrums in regards to the recording, analysis, and interpretation of HFOs in the epileptic brain to critically highlight what is known and what is not about these enigmatic events. High-frequency oscillations reflect a range of neuronal processes contributing to overlapping frequencies from the lower 80 Hz to the very fast spectral frequency bands. Given their complex neuronal nature, HFOs are extremely sensitive to recording conditions and analytical approaches. We provide a list of recommendations that could help to obtain comparable HFO signals in clinical and basic epilepsy research. Adopting basic standards will facilitate data sharing and interpretation that collectively will aid in understanding the role of HFOs in health and disease for translational purpose.
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Pallud J, Le Van Quyen M, Bielle F, Pellegrino C, Varlet P, Cresto N, Baulac M, Duyckaerts C, Kourdougli N, Chazal G, Devaux B, Rivera C, Miles R, Capelle L, Huberfeld G. Cortical GABAergic excitation contributes to epileptic activities around human glioma. Sci Transl Med 2015; 6:244ra89. [PMID: 25009229 DOI: 10.1126/scitranslmed.3008065] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Brain gliomas are highly epileptogenic. Excitatory glutamatergic mechanisms are involved in the generation of epileptic activities in the neocortex surrounding gliomas. However, chloride homeostasis is known to be perturbed in glioma cells. Thus, the contribution of γ-aminobutyric acidergic (GABAergic) mechanisms that depend on intracellular chloride merits closer study. We studied the occurrence, networks, cells, and signaling basis of epileptic activities in neocortical slices from the peritumoral surgical margin resected around human brain gliomas. Postoperative glioma tissue from 69% of patients spontaneously generated interictal-like discharges, synchronized, with a high-frequency oscillation signature, in superficial layers of neocortex around areas of glioma infiltration. Interictal-like events depended both on glutamatergic AMPA receptor-mediated transmission and on depolarizing GABAergic signaling. GABA released by interneurons depolarized 65% of pyramidal cells, in which chloride homeostasis was perturbed because of changes in expression of neuronal chloride cotransporters: KCC2 (K-Cl cotransporter 2) was reduced by 42% and expression of NKCC1 (Na-K-2Cl cotransporter 1) increased by 144%. Ictal-like activities were initiated by convulsant stimuli exclusively in these epileptogenic areas. This study shows that epileptic activities are sustained by excitatory effects of GABA in human peritumoral neocortex, as reported in temporal lobe epilepsies, suggesting that both glutamate and GABA signaling and cellular chloride regulation processes, all also involved in oncogenesis as already shown, induce an imbalance between synaptic excitation and inhibition underlying epileptic discharges in glioma patients. Thus, the control of chloride in neurons and glioma cells may provide a therapeutic target for patients with epileptogenic gliomas.
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Affiliation(s)
- Johan Pallud
- Institut du Cerveau et de la Moelle Epinière, INSERM UMRS975, CNRS UMR7225, Université Pierre et Marie Curie (UPMC), Paris, France.,Service de Neurochirurgie, Centre Hospitalier Sainte-Anne, Paris, France.,Université Paris Descartes, France
| | - Michel Le Van Quyen
- Institut du Cerveau et de la Moelle Epinière, INSERM UMRS975, CNRS UMR7225, Université Pierre et Marie Curie (UPMC), Paris, France
| | - Franck Bielle
- Service de Neuropathologie, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France
| | - Christophe Pellegrino
- INMED, Parc Scientifique de Luminy, Marseille, France.,Université de la Méditerranée, UMR S901 Aix-Marseille Université, Marseille, France
| | - Pascale Varlet
- Service de Neuropathologie, Centre Hospitalier Sainte-Anne, Paris, France
| | - Noemie Cresto
- Institut du Cerveau et de la Moelle Epinière, INSERM UMRS975, CNRS UMR7225, Université Pierre et Marie Curie (UPMC), Paris, France
| | - Michel Baulac
- Institut du Cerveau et de la Moelle Epinière, INSERM UMRS975, CNRS UMR7225, Université Pierre et Marie Curie (UPMC), Paris, France.,Unité d'Epileptologie, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France
| | - Charles Duyckaerts
- Service de Neuropathologie, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France
| | - Nazim Kourdougli
- INMED, Parc Scientifique de Luminy, Marseille, France.,Université de la Méditerranée, UMR S901 Aix-Marseille Université, Marseille, France
| | - Geneviève Chazal
- INMED, Parc Scientifique de Luminy, Marseille, France.,Université de la Méditerranée, UMR S901 Aix-Marseille Université, Marseille, France
| | - Bertrand Devaux
- Service de Neurochirurgie, Centre Hospitalier Sainte-Anne, Paris, France.,Université Paris Descartes, France
| | - Claudio Rivera
- INMED, Parc Scientifique de Luminy, Marseille, France.,Université de la Méditerranée, UMR S901 Aix-Marseille Université, Marseille, France.,Neuroscience Center, University of Helsinki, Finland
| | - Richard Miles
- Institut du Cerveau et de la Moelle Epinière, INSERM UMRS975, CNRS UMR7225, Université Pierre et Marie Curie (UPMC), Paris, France
| | - Laurent Capelle
- Institut du Cerveau et de la Moelle Epinière, INSERM UMRS975, CNRS UMR7225, Université Pierre et Marie Curie (UPMC), Paris, France.,Service de Neurochirurgie, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France
| | - Gilles Huberfeld
- Institut du Cerveau et de la Moelle Epinière, INSERM UMRS975, CNRS UMR7225, Université Pierre et Marie Curie (UPMC), Paris, France.,Service de Neuropathologie, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France.,Unité d'Epileptologie, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France.,Département de Neurophysiologie, UPMC, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France
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Huberfeld G, Blauwblomme T, Miles R. Hippocampus and epilepsy: Findings from human tissues. Rev Neurol (Paris) 2015; 171:236-51. [PMID: 25724711 PMCID: PMC4409112 DOI: 10.1016/j.neurol.2015.01.563] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/20/2015] [Indexed: 11/18/2022]
Abstract
Surgical removal of the epileptogenic zone provides an effective therapy for several focal epileptic syndromes. This surgery offers the opportunity to study pathological activity in living human tissue for pharmacoresistant partial epilepsy syndromes including temporal lobe epilepsies with hippocampal sclerosis, cortical dysplasias, epilepsies associated with tumors and developmental malformations. Slices of tissue from patients with these syndromes retain functional neuronal networks and may generate epileptic activities. The properties of cells in this tissue may not be greatly changed, but excitatory synaptic transmission is often enhanced and GABAergic inhibition is preserved. Typically epileptic activity is not generated spontaneously by the neocortex, whether dysplastic or not, but can be induced by convulsants. The initiation of ictal discharges in the neocortex depends on both GABAergic signaling and increased extracellular potassium. In contrast, a spontaneous interictal-like activity is generated by tissues from patients with temporal lobe epilepsies associated with hippocampal sclerosis. This activity is initiated, not in the hippocampus but in the subiculum, an output region, which projects to the entorhinal cortex. Interictal events seem to be triggered by GABAergic cells, which paradoxically excite about 20% of subicular pyramidal cells while simultaneously inhibiting the majority. Interictal discharges thus depend on both GABAergic and glutamatergic signaling. The depolarizing effects of GABA depend on a pathological elevation in levels of chloride in some subicular cells, similar to those of developmentally immature cells. Such defect is caused by a perturbed expression of the cotransporters regulating intracellular chloride concentration, the importer NKCC1 and the extruder KCC2. Blockade of NKCC1 actions by the diuretic bumetanide restores intracellular chloride and thus hyperpolarizing GABAergic actions and consequently suppressing interictal activity.
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Affiliation(s)
- G Huberfeld
- Département de neurophysiologie, Sorbonne universités, UPMC - université Paris 06, UPMC, CHU de la Pitié-Salpêtrière, 47-83, boulevard de l'Hôpital, 75013 Paris, France; INSERM Unit U1129 Infantile Epilepsies and Brain Plasticity, University Paris Descartes, Sorbonne Paris Cité, CEA, 12, rue de l'École-de-Médecine, 75006 Paris, France.
| | - T Blauwblomme
- INSERM Unit U1129 Infantile Epilepsies and Brain Plasticity, University Paris Descartes, Sorbonne Paris Cité, CEA, 12, rue de l'École-de-Médecine, 75006 Paris, France; Neurosurgery Department, Necker-Enfants Malades Hospital, University Paris Descartes, PRES Sorbonne Paris Cité, 12, rue de l'École-de-Médecine, 75006 Paris, France
| | - R Miles
- Inserm U1127, CNRS UMR7225, Sorbonne universités, UPMC - université Paris 6 UMR S1127, Institut du cerveau et de la moelle épinière, 47, boulevard de l'Hôpital, 75013 Paris, France
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12
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Alvarado-Rojas C, Huberfeld G, Baulac M, Clemenceau S, Charpier S, Miles R, de la Prida LM, Le Van Quyen M. Different mechanisms of ripple-like oscillations in the human epileptic subiculum. Ann Neurol 2014; 77:281-90. [PMID: 25448920 DOI: 10.1002/ana.24324] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 11/10/2014] [Accepted: 11/21/2014] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Transient high-frequency oscillations (HFOs; 150-600Hz) in local field potentials generated by human hippocampal and parahippocampal areas have been related to both physiological and pathological processes. The cellular basis and effects of normal and abnormal forms of HFOs have been controversial. This lack of agreement is clinically significant, because HFOs may be good markers of epileptogenic areas. Better defining the neuronal correlate of specific HFO frequency bands could improve electroencephalographic analyses made before epilepsy surgery. METHODS Here, we recorded HFOs in slices of the subiculum prepared from human hippocampal tissue resected for treatment of pharmacoresistant epilepsy. With combined intra- or juxtacellular and extracellular recordings, we examined the cellular correlates of interictal and ictal HFO events. RESULTS HFOs occurred spontaneously in extracellular field potentials during interictal discharges (IIDs) and also during pharmacologically induced preictal discharges (PIDs) preceding ictal-like events. Many of these events included frequencies >250Hz and so might be considered pathological, but a significant proportion were spectrally similar to physiological ripples (150-250Hz). We found that IID ripples were associated with rhythmic γ-aminobutyric acidergic and glutamatergic synaptic potentials with moderate neuronal firing. In contrast, PID ripples were associated with depolarizing synaptic inputs frequently reaching the threshold for bursting in most pyramidal cells. INTERPRETATION Our data suggest that IID and PID ripple-like oscillations (150-250Hz) in human epileptic hippocampus are associated with 2 distinct population activities that rely on different cellular and synaptic mechanisms. Thus, the ripple band could not help to disambiguate the underlying cellular processes.
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Affiliation(s)
- Catalina Alvarado-Rojas
- Brain and Spine Institute, Pitié-Salpêtrière Hospital, Paris, France; Pierre and Marie Curie University, Paris
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13
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Cid E, Gomez-Dominguez D, Martin-Lopez D, Gal B, Laurent F, Ibarz JM, Francis F, Menendez de la Prida L. Dampened hippocampal oscillations and enhanced spindle activity in an asymptomatic model of developmental cortical malformations. Front Syst Neurosci 2014; 8:50. [PMID: 24782720 PMCID: PMC3995045 DOI: 10.3389/fnsys.2014.00050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/18/2014] [Indexed: 11/13/2022] Open
Abstract
Developmental cortical malformations comprise a large spectrum of histopathological brain abnormalities and syndromes. Their genetic, developmental and clinical complexity suggests they should be better understood in terms of the complementary action of independently timed perturbations (i.e., the multiple-hit hypothesis). However, understanding the underlying biological processes remains puzzling. Here we induced developmental cortical malformations in offspring, after intraventricular injection of methylazoxymethanol (MAM) in utero in mice. We combined extensive histological and electrophysiological studies to characterize the model. We found that MAM injections at E14 and E15 induced a range of cortical and hippocampal malformations resembling histological alterations of specific genetic mutations and transplacental mitotoxic agent injections. However, in contrast to most of these models, intraventricularly MAM-injected mice remained asymptomatic and showed no clear epilepsy-related phenotype as tested in long-term chronic recordings and with pharmacological manipulations. Instead, they exhibited a non-specific reduction of hippocampal-related brain oscillations (mostly in CA1); including theta, gamma and HFOs; and enhanced thalamocortical spindle activity during non-REM sleep. These data suggest that developmental cortical malformations do not necessarily correlate with epileptiform activity. We propose that the intraventricular in utero MAM approach exhibiting a range of rhythmopathies is a suitable model for multiple-hit studies of associated neurological disorders.
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Affiliation(s)
- Elena Cid
- Laboratorio de Circuitos Neuronales, Instituto Cajal, CSIC Madrid, Spain
| | | | - David Martin-Lopez
- Laboratorio de Circuitos Neuronales, Instituto Cajal, CSIC Madrid, Spain ; Servicio de Neurofisiologia Clínica, Hospital General Universitario Gregorio Marañón Madrid, Spain
| | - Beatriz Gal
- Laboratorio de Circuitos Neuronales, Instituto Cajal, CSIC Madrid, Spain ; Universidad Europea de Madrid, Ciencias Biomédicas Básicas Madrid, Spain
| | - François Laurent
- Laboratorio de Circuitos Neuronales, Instituto Cajal, CSIC Madrid, Spain
| | - Jose M Ibarz
- Servicio de Neurobiología, Instituto Ramón y Cajal de Investigación Sanitaria Madrid, Spain
| | - Fiona Francis
- Institut du Fer à Moulin Paris, France ; Sorbonne Universités, Université Pierre et Marie Curie Paris, France ; Institut National de la Santé et de la Recherche Médicale UMRS 839 Paris, France
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14
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Florez CM, McGinn RJ, Lukankin V, Marwa I, Sugumar S, Dian J, Hazrati LN, Carlen PL, Zhang L, Valiante TA. In vitro recordings of human neocortical oscillations. ACTA ACUST UNITED AC 2013; 25:578-97. [PMID: 24046077 DOI: 10.1093/cercor/bht235] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Electrophysiological oscillations are thought to create temporal windows of communication between brain regions. We show here that human cortical slices maintained in vitro can generate oscillations similar to those observed in vivo. We have characterized these oscillations using local field potential and whole-cell recordings obtained from neocortical slices acquired during epilepsy surgery. We confirmed that such neocortical slices maintain the necessary cellular and circuitry components, and in particular inhibitory mechanisms, to manifest oscillatory activity when exposed to glutamatergic and cholinergic agonists. The generation of oscillations was dependent on intact synaptic activity and muscarinic receptors. Such oscillations differed in electrographic and pharmacological properties from epileptiform activity. Two types of activity, theta oscillations and high gamma activity, uniquely characterized this model-activity not typically observed in animal cortical slices. We observed theta oscillations to be synchronous across cortical laminae suggesting a novel role of theta as a substrate for interlaminar communication. As well, we observed cross-frequency coupling (CFC) between theta phase and high gamma amplitude similar to that observed in vivo. The high gamma "bursts" generated by such CFC varied in their frequency content, suggesting that this variability may underlie the broadband nature of high gamma activity.
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Affiliation(s)
- C M Florez
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8
| | - R J McGinn
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8
| | - V Lukankin
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8
| | - I Marwa
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8
| | - S Sugumar
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8
| | - J Dian
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8
| | - L N Hazrati
- Department of Neuropathology, Toronto General Hospital, Toronto, ON, Canada M5G 2C4 Tanz Center for Research in Neurodegenerative Diseases, Toronto, ON, Canada M5S 3H2
| | - P L Carlen
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8 Krembil Neuroscience Center, Toronto, ON, Canada, M5T 2S8 Division of Neurology, Faculty of Medicine and
| | - L Zhang
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8 Division of Neurology, Faculty of Medicine and
| | - T A Valiante
- Division of Fundamental Neurobiology, Toronto Western Hospital Research Institute, Toronto, Canada M5T 2S8 Krembil Neuroscience Center, Toronto, ON, Canada, M5T 2S8 Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada, M5T 1P5
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15
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Palmigiano A, Pastor J, García de Sola R, Ortega GJ. Stability of synchronization clusters and seizurability in temporal lobe epilepsy. PLoS One 2012; 7:e41799. [PMID: 22844524 PMCID: PMC3402406 DOI: 10.1371/journal.pone.0041799] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/25/2012] [Indexed: 01/03/2023] Open
Abstract
PURPOSE Identification of critical areas in presurgical evaluations of patients with temporal lobe epilepsy is the most important step prior to resection. According to the "epileptic focus model", localization of seizure onset zones is the main task to be accomplished. Nevertheless, a significant minority of epileptic patients continue to experience seizures after surgery (even when the focus is correctly located), an observation that is difficult to explain under this approach. However, if attention is shifted from a specific cortical location toward the network properties themselves, then the epileptic network model does allow us to explain unsuccessful surgical outcomes. METHODS The intraoperative electrocorticography records of 20 patients with temporal lobe epilepsy were analyzed in search of interictal synchronization clusters. Synchronization was analyzed, and the stability of highly synchronized areas was quantified. Surrogate data were constructed and used to statistically validate the results. Our results show the existence of highly localized and stable synchronization areas in both the lateral and the mesial areas of the temporal lobe ipsilateral to the clinical seizures. Synchronization areas seem to play a central role in the capacity of the epileptic network to generate clinical seizures. Resection of stable synchronization areas is associated with elimination of seizures; nonresection of synchronization clusters is associated with the persistence of seizures after surgery. DISCUSSION We suggest that synchronization clusters and their stability play a central role in the epileptic network, favoring seizure onset and propagation. We further speculate that the stability distribution of these synchronization areas would differentiate normal from pathologic cases.
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Affiliation(s)
| | - Jesús Pastor
- Instituto de Investigación Sanitaria Hospital de la Princesa, Madrid, Spain
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16
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Tryba AK, Kaczorowski CC, Ben-Mabrouk F, Elsen FP, Lew SM, Marcuccilli CJ. Rhythmic intrinsic bursting neurons in human neocortex obtained from pediatric patients with epilepsy. Eur J Neurosci 2011; 34:31-44. [PMID: 21722205 DOI: 10.1111/j.1460-9568.2011.07746.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neocortical oscillations result from synchronized activity of a synaptically coupled network and can be strongly influenced by the intrinsic firing properties of individual neurons. As such, the intrinsic electroresponsive properties of individual neurons may have important implications for overall network function. Rhythmic intrinsic bursting (rIB) neurons are of particular interest, as they are poised to initiate and/or strongly influence network oscillations. Although neocortical rIB neurons have been recognized in multiple species, the current study is the first to identify and characterize rIB neurons in the human neocortex. Using whole-cell current-clamp recordings, rIB neurons (n = 12) are identified in human neocortical tissue resected from pediatric patients with intractable epilepsy. In contrast to human regular spiking neurons (n = 12), human rIB neurons exhibit rhythmic bursts of action potentials at frequencies of 0.1-4 Hz. These bursts persist after blockade of fast excitatory neurotransmission and voltage-gated calcium channels. However, bursting is eliminated by subsequent application of the persistent sodium current (I(NaP)) blocker, riluzole. In the presence of riluzole (either 10 or 20 μm), human rIB neurons no longer burst, but fire tonically like regular spiking neurons. These data demonstrate that I(NaP) plays a critical role in intrinsic oscillatory activity observed in rIB neurons in the human neocortex. It is hypothesized that aberrant changes in I(NaP) expression and/or function may ultimately contribute to neurological diseases that are linked to abnormal network activity, such as epilepsy.
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Affiliation(s)
- Andrew K Tryba
- Department of Physiology, The Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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17
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Glutamatergic pre-ictal discharges emerge at the transition to seizure in human epilepsy. Nat Neurosci 2011; 14:627-34. [PMID: 21460834 DOI: 10.1038/nn.2790] [Citation(s) in RCA: 220] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 03/02/2011] [Indexed: 11/08/2022]
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Neuronal bursting properties in focal and parafocal regions in pediatric neocortical epilepsy stratified by histology. J Clin Neurophysiol 2011; 27:387-97. [PMID: 21076335 DOI: 10.1097/wnp.0b013e3181fe06d8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
To test the hypothesis that focal and parafocal neocortical tissue from pediatric patients with intractable epilepsy exhibits cellular and synaptic differences, the authors characterized the propensity of these neurons to generate (a) voltage-dependent bursting and (b) synaptically driven paroxysmal depolarization shifts. Neocortical slices were prepared from tissue resected from patients with intractable epilepsy. Multiunit network activity and simultaneous whole-cell patch recordings were made from neurons from three patient groups: (1) those with normal histology; (2) those with mild and severe cortical dysplasia; and (3) those with abnormal pathology but without cortical dysplasia. Seizure-like activity was characterized by population bursting with concomitant bursting in intracellularly recorded cortical neurons (n = 59). The authors found significantly more N-methyl-D-aspartic acid-driven voltage-dependent bursting neurons in focal versus parafocal tissue in patients with severe cortical dysplasia (P < 0.01). Occurrence of paroxysmal depolarization shifts and burst amplitude and burst duration were significantly related to tissue type: focal or parafocal (P < 0.05). The authors show that functional differences between focal and parafocal tissue in patients with severe cortical dysplasia exist. There are functional differences between patient groups with different histology, and bursting properties can be significantly associated with the distinction between focal and parafocal tissue.
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Huberfeld G, Clemenceau S, Cohen I, Pallud J, Wittner L, Navarro V, Baulac M, Miles R. [Epileptiform activities generated in vitro by human temporal lobe tissue]. Neurochirurgie 2008; 54:148-58. [PMID: 18420229 DOI: 10.1016/j.neuchi.2008.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Accepted: 02/13/2008] [Indexed: 11/28/2022]
Abstract
Drug-resistant partial epilepsies, including temporal lobe epilepsies with hippocampal sclerosis and cortical dysplasias, offer the opportunity to study human epileptic activity in vitro since the preferred therapy often consists of the surgical removal of the epileptogenic zone. Slices of this tissue retain functional neuronal networks and may generate epileptic activity. The properties of cells in this tissue do not seem to be significantly changed, but excitatory synaptic characteristics are enhanced and GABAergic inhibition is preserved. Typically, epileptic activity is not generated spontaneously by the neocortex, whether dysplastic or not, but can be induced by convulsants. The initiation of ictal discharges in neocortex depends on both GABAergic signaling and increased extracellular potassium. In contrast, a spontaneous interictal-like activity is generated by tissues from patients with temporal lobe epilepsies associated with hippocampal sclerosis. This activity is initiated not in the hippocampus but in the subiculum, an output region that projects to the entorhinal cortex. Interictal events seem to be triggered by GABAergic cells, which paradoxically excite approximately 20% of subicular pyramidal cells, while simultaneously inhibiting the majority. Interictal discharges are therefore sustained by both GABAergic and glutamatergic signaling. The atypical depolarizing effects of GABA depend on a pathological elevation in the basal levels of chloride in some subicular cells, similar to those of developmentally immature cells. This defect is caused by the perturbation of the expression of the cotransporters regulating the intracellular chloride concentration, the importer NKCC1, and the extruder KCC2. Blockade of excessive NKCC1 by the diuretic bumetanide restores intracellular chloride and thus hyperpolarizing GABAergic actions, suppressing interictal activity.
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Affiliation(s)
- G Huberfeld
- Inserm U739 Cortex & Epilepsie, université Pierre-et-Marie-Curie, CHU de la Pitié-Salpêtrière, 105, boulevard de l'Hôpital, 75013 Paris, France.
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20
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Ortega GJ, Menendez de la Prida L, Sola RG, Pastor J. Synchronization Clusters of Interictal Activity in the Lateral Temporal Cortex of Epileptic Patients: Intraoperative Electrocorticographic Analysis. Epilepsia 2008; 49:269-80. [PMID: 17825075 DOI: 10.1111/j.1528-1167.2007.01266.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Drug-resistant temporal lobe epilepsy (TLE) can be treated by tailored surgery guided by electrocorticography (ECoG). Although its value is still controversial, ECoG activity can provide continuous information on intracortical interactions that may be useful to understand the pathophysiology of TLE. The goal of this study is to characterize local interactions in multichannel ECoG recordings of the lateral cortex of TLE patients using three synchronization measures and to link this information with surgical outcome. METHODS Intraoperative ECoG recordings from 29 TLE patients were obtained using grids of 20 electrodes (4 x 5) covering regions T1, T2, and T3 of the lateral temporal lobe. Linear correlation, mutual information, and phase synchronization were calculated to quantify lateral intracortical interactions. Surrogate data files were generated to test results statistically. RESULTS By distributing locally the interactions between the electrodes, we characterized the spatial patterns of ECoG activity. We found clusters of synchronized activity at specific areas of the lateral temporal cortex in most patients. Methodologically, linear correlation and phase synchronization performed better than mutual information for cluster discrimination. ROC analysis suggested that surgical removal of sharply defined synchronization clusters correlated with seizure control. CONCLUSIONS Our results show that synchronous intraoperative ECoG activity emerges from specific cortical areas that are highly differentiated from the rest of the temporal cortex. This suggests that synchronization analysis could be used to functionally map into the temporal cortex of TLE patients. Moreover, our results suggest that these sites might be involved in the circuits that participate in clinical seizures.
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Žiburkus J, Cressman JR, Barreto E, Schiff. SJ. Interneuron and pyramidal cell interplay during in vitro seizure-like events. J Neurophysiol 2006; 95:3948-54. [PMID: 16554499 PMCID: PMC1469233 DOI: 10.1152/jn.01378.2005] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Excitatory and inhibitory (EI) interactions shape network activity. However, little is known about the EI interactions in pathological conditions such as epilepsy. To investigate EI interactions during seizure-like events (SLEs), we performed simultaneous dual and triple whole cell and extracellular recordings in pyramidal cells and oriens interneurons in rat hippocampal CA1. We describe a novel pattern of interleaving EI activity during spontaneous in vitro SLEs generated by the potassium channel blocker 4-aminopyridine in the presence of decreased magnesium. Interneuron activity was increased during interictal periods. During ictal discharges interneurons entered into long-lasting depolarization block (DB) with suppression of spike generation; simultaneously, pyramidal cells produced spike trains with increased frequency (6-14 Hz) and correlation. After this period of runaway excitation, interneuron postictal spiking resumed and pyramidal cells became progressively quiescent. We performed correlation measures of cell-pair interactions using either the spikes alone or the subthreshold postsynaptic interspike signals. EE spike correlation was notably increased during interneuron DB, whereas subthreshold EE correlation decreased. EI spike correlations increased at the end of SLEs, whereas II subthreshold correlations increased during DB. Our findings underscore the importance of complex cell-type-specific neuronal interactions in the formation of seizure patterns.
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Affiliation(s)
- Jokūbas Žiburkus
- Center for Neural Dynamics, Krasnow Institute
- Contact information Jokūbas Žiburkus, George Mason University, MS2A1, Krasnow Institute, Center for Neural Dynamics, Fairfax, VA 22030, Tel. 703-993-4372/4332, Fax. 703-993-4440, e-mail:
| | | | - Ernest Barreto
- Center for Neural Dynamics, Krasnow Institute
- Department of Physics and Astronomy
- Program in Neuroscience and
| | - Steven J. Schiff.
- Center for Neural Dynamics, Krasnow Institute
- Program in Neuroscience and
- Department of Psychology, George Mason University, MS2A1, Fairfax, VA 22030
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Avoli M, Louvel J, Pumain R, Köhling R. Cellular and molecular mechanisms of epilepsy in the human brain. Prog Neurobiol 2006; 77:166-200. [PMID: 16307840 DOI: 10.1016/j.pneurobio.2005.09.006] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 07/27/2005] [Accepted: 09/20/2005] [Indexed: 12/20/2022]
Abstract
Animal models have provided invaluable data for identifying the pathogenesis of epileptic disorders. Clearly, the relevance of these experimental findings would be strengthened by the demonstration that similar fundamental mechanisms are at work in the human epileptic brain. Epilepsy surgery has indeed opened the possibility to directly study the functional properties of human brain tissue in vitro, and to analyze the mechanisms underlying seizures and epileptogenesis. Here, we summarize the findings obtained over the last 40 years from electrophysiological, histochemical and molecular experiments made with the human brain tissue. In particular, this review will focus on (i) the synaptic and non-synaptic properties of neocortical neurons along with their ability to produce synchronous activity; (ii) the anatomical and functional alterations that characterize limbic structures in patients presenting with mesial temporal lobe epilepsy; (iii) the issue of antiepileptic drug action and resistance; and (iv) the pathophysiology of seizure genesis in Taylor's type focal cortical dysplasia. Finally, we will address some of the problems that are inherent to this type of experimental approach, in particular the lack of proper controls and possible strategies to obviate this limitation.
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Affiliation(s)
- Massimo Avoli
- Montreal Neurological Institute and Departments of Neurology and Neurosurgery, and of Physiology, McGill University, Montreal, Canada.
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23
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Povysheva NV, Gonzalez-Burgos G, Zaitsev AV, Kröner S, Barrionuevo G, Lewis DA, Krimer LS. Properties of excitatory synaptic responses in fast-spiking interneurons and pyramidal cells from monkey and rat prefrontal cortex. ACTA ACUST UNITED AC 2005; 16:541-52. [PMID: 16033926 DOI: 10.1093/cercor/bhj002] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the prefrontal cortex (PFC) during working memory tasks fast-spiking (FS) interneurons might shape the spatial selectivity of pyramidal cell firing. In order to provide time control of pyramidal cell activity, incoming excitatory inputs should excite FS interneurons more vigorously than pyramidal cells. This can be achieved if subthreshold excitatory responses of interneurons are considerably stronger and faster than those in pyramidal neurons. Here we compared the functional properties of excitatory post-synaptic potentials (EPSPs) between pyramidal cells and FS interneurons in slices from monkey dorsolateral PFC and rat prelimbic cortex. Miniature, unitary (in connected pairs or by minimal stimulation) and compound (evoked by electrical stimulation of the white matter) EPSPs were recorded in whole cell mode. We found that EPSPs were significantly larger and faster in FS interneurons than those recorded from pyramidal cells, consistent with the idea of more efficient recruitment of FS interneurons compared to pyramidal neurons. Similar results were obtained in monkey and rat PFC, suggesting a stable role of FS interneurons in this circuitry across species.
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Affiliation(s)
- N V Povysheva
- Department of Psychiatry, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213-2593, USA.
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Fujiwara-Tsukamoto Y, Isomura Y, Kaneda K, Takada M. Synaptic interactions between pyramidal cells and interneurone subtypes during seizure-like activity in the rat hippocampus. J Physiol 2004; 557:961-79. [PMID: 15107470 PMCID: PMC1665157 DOI: 10.1113/jphysiol.2003.059915] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We have recently reported that excitatory GABAergic and glutamatergic mechanisms may be involved in the generation of seizure-like (ictal) rhythmic synchronization (afterdischarge), induced by a strong synaptic stimulation of the CA1 pyramidal cells in the mature rat hippocampus in vitro. To clarify the network mechanism of this neuronal synchronization, dual whole-cell patch-clamp recordings of the afterdischarge responses were performed simultaneously from a variety of interneurones and their neighbouring pyramidal cells in hippocampal CA1-isolated slice preparations. According to morphological and electrophysiological criteria, the recorded interneurones were then classified into distinct subtypes. The non-fast-spiking interneurones located in the strata lacunosum-moleculare and radiatum hardly discharged during the afterdischarge, whereas most of the fast-spiking and non-fast-spiking interneurones in the strata oriens and pyramidale, including the basket, chandelier and bistratified cells, exhibited prominent firings that were precisely synchronous with oscillatory responses in the pyramidal cells. Field potential recordings showed that excitatory synaptic transmissions might take place primarily in the strata oriens and pyramidale during the afterdischarge. Restricted lesions in the strata oriens and pyramidale, but not in the other layers, resulted in the complete desynchronization of afterdischarge activity, and also, local application of glutamate receptor antagonists to these layers blocked the expression of afterdischarge. The present findings indicate that the neuronal synchronization of epileptic afterdischarge may be accomplished in a 'positive feedback circuit' formed by the excitatory GABAergic interneurones and the glutamatergic pyramidal cells within the strata oriens and/or pyramidale of the hippocampal CA1 region.
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Affiliation(s)
- Yoko Fujiwara-Tsukamoto
- Department of System Neuroscience, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan
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