1
|
Wang F, Wang Y, Zhang QY, Hu KY, Song YJ, Yang L, Fei F, Xu CL, Cui SL, Ruan YP, Wang Y, Chen Z. Small-molecule caspase-1 inhibitor CZL80 terminates refractory status epilepticus via inhibition of glutamatergic transmission. Acta Pharmacol Sin 2024; 45:1381-1392. [PMID: 38514863 PMCID: PMC11192899 DOI: 10.1038/s41401-024-01257-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/29/2024] [Indexed: 03/23/2024] Open
Abstract
Status epilepticus (SE), a serious and often life-threatening medical emergency, is characterized by abnormally prolonged seizures. It is not effectively managed by present first-line anti-seizure medications and could readily develop into drug resistance without timely treatment. In this study, we highlight the therapeutic potential of CZL80, a small molecule that inhibits caspase-1, in SE termination and its related mechanisms. We found that delayed treatment of diazepam (0.5 h) easily induces resistance in kainic acid (KA)-induced SE. CZL80 dose-dependently terminated diazepam-resistant SE, extending the therapeutic time window to 3 h following SE, and also protected against neuronal damage. Interestingly, the effect of CZL80 on SE termination was model-dependent, as evidenced by ineffectiveness in the pilocarpine-induced SE. Further, we found that CZL80 did not terminate KA-induced SE in Caspase-1-/- mice but partially terminated SE in IL1R1-/- mice, suggesting the SE termination effect of CZL80 was dependent on the caspase-1, but not entirely through the downstream IL-1β pathway. Furthermore, in vivo calcium fiber photometry revealed that CZL80 completely reversed the neuroinflammation-augmented glutamatergic transmission in SE. Together, our results demonstrate that caspase-1 inhibitor CZL80 terminates diazepam-resistant SE by blocking glutamatergic transmission. This may be of great therapeutic significance for the clinical treatment of refractory SE.
Collapse
Affiliation(s)
- Fei Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Yu Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Qing-Yang Zhang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Ke-Yu Hu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Ying-Jie Song
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Lin Yang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Fan Fei
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Ceng-Lin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Sun-Liang Cui
- Key Laboratory of Medical Neurobiology of The Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Ye-Ping Ruan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
- Key Laboratory of Medical Neurobiology of The Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China.
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, Department of Neurology, The First Affiliated Hospital, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
- Key Laboratory of Medical Neurobiology of The Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
2
|
Capitano F, Kuchenbuch M, Lavigne J, Chaptoukaev H, Zuluaga MA, Lorenzi M, Nabbout R, Mantegazza M. Preictal dysfunctions of inhibitory interneurons paradoxically lead to their rebound hyperactivity and to low-voltage-fast onset seizures in Dravet syndrome. Proc Natl Acad Sci U S A 2024; 121:e2316364121. [PMID: 38809712 PMCID: PMC11161744 DOI: 10.1073/pnas.2316364121] [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: 09/26/2023] [Accepted: 05/01/2024] [Indexed: 05/31/2024] Open
Abstract
Epilepsies have numerous specific mechanisms. The understanding of neural dynamics leading to seizures is important for disclosing pathological mechanisms and developing therapeutic approaches. We investigated electrographic activities and neural dynamics leading to convulsive seizures in patients and mouse models of Dravet syndrome (DS), a developmental and epileptic encephalopathy in which hypoexcitability of GABAergic neurons is considered to be the main dysfunction. We analyzed EEGs from DS patients carrying a SCN1A pathogenic variant, as well as epidural electrocorticograms, hippocampal local field potentials, and hippocampal single-unit neuronal activities in Scn1a+/- and Scn1aRH/+ DS mice. Strikingly, most seizures had low-voltage-fast onset in both patients and mice, which is thought to be generated by hyperactivity of GABAergic interneurons, the opposite of the main pathological mechanism of DS. Analyzing single-unit recordings, we observed that temporal disorganization of the firing of putative interneurons in the period immediately before the seizure (preictal) precedes the increase of their activity at seizure onset, together with the entire neuronal network. Moreover, we found early signatures of the preictal period in the spectral features of hippocampal and cortical field potential of Scn1a mice and of patients' EEG, which are consistent with the dysfunctions that we observed in single neurons and that allowed seizure prediction. Therefore, the perturbed preictal activity of interneurons leads to their hyperactivity at the onset of generalized seizures, which have low-voltage-fast features that are similar to those observed in other epilepsies and are triggered by hyperactivity of GABAergic neurons. Preictal spectral features may be used as predictive seizure biomarkers.
Collapse
Affiliation(s)
- Fabrizio Capitano
- University Cote d’Azur, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis06560, France
- CNRS UMR 7275, Valbonne-Sophia Antipolis06560, France
- Inserm U1323, Valbonne-Sophia Antipolis06650, France
| | - Mathieu Kuchenbuch
- Reference Centre for Rare Epilepsies, Member of European Reference Network EpiCARE, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris75015, France
- Laboratory of Translational Research for Neurological Disorders, Inserm UMR 1163, Imagine Institute, Université Paris Cité, Paris75015, France
| | - Jennifer Lavigne
- University Cote d’Azur, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis06560, France
- CNRS UMR 7275, Valbonne-Sophia Antipolis06560, France
- Inserm U1323, Valbonne-Sophia Antipolis06650, France
| | | | | | - Marco Lorenzi
- University Cote d’Azur, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis06560, France
- Epione Research team, Inria Center of Université Côte d’Azur, Biot-Sophia Antipolis06410, France
| | - Rima Nabbout
- Reference Centre for Rare Epilepsies, Member of European Reference Network EpiCARE, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris, Paris75015, France
- Laboratory of Translational Research for Neurological Disorders, Inserm UMR 1163, Imagine Institute, Université Paris Cité, Paris75015, France
| | - Massimo Mantegazza
- University Cote d’Azur, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis06560, France
- CNRS UMR 7275, Valbonne-Sophia Antipolis06560, France
- Inserm U1323, Valbonne-Sophia Antipolis06650, France
| |
Collapse
|
3
|
Goodman JH. It Matters Who Starts the Fire in Mesial Temporal Lobe Epilepsy. Epilepsy Curr 2024; 24:197-199. [PMID: 38898905 PMCID: PMC11185215 DOI: 10.1177/15357597241238901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024] Open
Abstract
CA3 Principal Cell Activation Triggers Hypersynchronous-Onset Seizures in a Mouse Model of Mesial Temporal Lobe Epilepsy Wang S, Lévesque M, Fisher TAJ, Kennedy TE, Avoli M. J Neurophysiol . 2023;130(4):1041-1052. doi:10.1152/jn.00244.2023 Mesial temporal lobe epilepsy (MTLE) is the most common form of focal epilepsy, and it is characterized by seizures that are often refractory to medications. Seizures in MTLE have two main patterns of onset that have been termed hypersynchronous (HYP) and low-voltage fast (LVF) and are believed to mainly depend on the activity of excitatory principal cells and inhibitory interneurons, respectively. In this study, we investigated whether unilateral open-loop optogenetic activation of CaMKII-positive principal cells in the hippocampus CA3 region favors the generation of spontaneous HYP seizures in kainic acid-treated (KA) CaMKII-ChR2 mice. Optogenetic activation of CA3 principal cells (1 Hz, 180 s ON, 220 s OFF) was implemented for 15 days after KA-induced status epilepticus. We found that both LVF and HYP seizures occurred in nonstimulated CaMKII-ChR2 (n = 6) and stimulated CaMKII-Cre (n = 5) mice. In contrast, optogenetic activation of principal cells in CaMKII-ChR2 mice (n = 5) triggered only HYP seizures that were characterized by high fast ripple (250–500 Hz) rates during the pre-ictal and ictal periods. These results provide firm evidence that in MTLE spontaneous seizures with different onset patterns depend on distinct neuronal network mechanisms of generation. They also demonstrate that HYP seizures occurring in vivo along with their associated fast ripples depend on the activity of principal cells in the CA3 region. NEW & NOTEWORTHY Previous evidence suggested that different seizure onset patterns rely on the activity of distinct neuronal populations. In this study, we show for the first time that in vivo optogenetic stimulation of CaMKII principal cells in kainic acid-treated mice triggers hypersynchronous-onset seizures that are associated with fast ripples. Our findings indicate that in patients with predominant HYP-onset seizures, anticonvulsant treatments should be aimed at limiting the firing of principal neurons in the seizure onset zone.
Collapse
Affiliation(s)
- Jeffrey H Goodman
- Department of Developmental Neurobiology, NYS Institute for Basic Research in Developmental Disabilities
| |
Collapse
|
4
|
Kalogeropoulos K, Psarropoulou C. Immature Status Epilepticus Alters the Temporal Relationship between Hippocampal Interictal Epileptiform Discharges and High-frequency Oscillations. Neuroscience 2024; 543:108-120. [PMID: 38401712 DOI: 10.1016/j.neuroscience.2024.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
The aim was to investigate the long-term effects of a single episode of immature Status Epilepticus (SE) on the excitability of the septal and temporal hippocampus in vitro, by studying the relationship between interictal-like epileptiform discharges (IEDs) and high-frequency oscillations (HFOs; Ripples, Rs and Fast Ripples, FRs). A pentylenetetrazol-induced Status Epilepticus-(SE)-like generalized seizure was induced at postnatal day 20 in 22 male and female juvenile rats, sacrificed >40 days later to prepare hippocampal slices. Spontaneous IEDs induced by Mg2+-free ACSF were recorded from the CA3 area of temporal (T) or septal (S) slices. Recordings were band-pass filtered off-line revealing Rs and FRs and a series of measurements were conducted, with mean values compared with those obtained from age-matched controls (CTRs). In CTR S (vs T) slices, we recorded longer R & FR durations, a longer HFO-IED temporal overlap, higher FR peak power and more frequent FR initiation preceding IEDs (% events). Post-SE, in T slices all types of events duration (IED, R, FR) and the time lag between their onsets (R-IED, FR-IED, R-FR) increased, while FR/R peak power decreased; in S slices, the IED 1st population spike and the FR amplitudes, the R and FR peak power and the (percent) events where Rs or FRs preceded IEDs all decreased. The CA3 IED-HFO relationship offers insights to the septal-to-temporal synchronization patterns; its post-juvenile-SE changes indicate permanent modifications in the septotemporal excitability gradient. Moreover, these findings are in line to region-specific regulation of various currents post-SE, as reported in literature.
Collapse
Affiliation(s)
- Konstantinos Kalogeropoulos
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, 45110, Greece.
| | - Caterina Psarropoulou
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, 45110, Greece.
| |
Collapse
|
5
|
Zhang M, Yang L, Li Z, Fei F, Zhou Y, Jiang D, Zheng Y, Cheng H, Wang Y, Xu C, Fang J, Wang S, Chen Z, Wang Y. Low-frequency stimulation in the zona incerta attenuates seizure via driving GABAergic neuronal activity. Neurobiol Dis 2024; 192:106424. [PMID: 38290566 DOI: 10.1016/j.nbd.2024.106424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 01/15/2024] [Accepted: 01/26/2024] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND Managing refractory epilepsy presents a significant a substantial clinical challenge. Deep brain stimulation (DBS) has emerged as a promising avenue for addressing refractory epilepsy. However, the optimal stimulation targets and effective parameters of DBS to reduce seizures remian unidentified. OBJECTIVES This study endeavors to scrutinize the therapeutic potential of DBS within the zona incerta (ZI) across diverse seizure models and elucidate the associated underlying mechanisms. METHODS We evaluated the therapeutic potential of DBS with different frequencies in the ZI on kainic acid (KA)-induced TLE model or M1-cortical seizures model, pilocarpine-induced M1-cortical seizure models, and KA-induced epilepsy model. Further, employing calcium fiber photometry combined with cell-specific ablation, we sought to clarified the causal role of ZI GABAergic neurons in mediating the therapeutic effects of DBS. RESULTS Our findings reveal that DBS in the ZI alleviated the severity of seizure activities in the KA-induced TLE model. Meanwhile, DBS attenuated seizure activities in KA- or pilocarpine-induced M1-cortical seizure model. In addition, DBS exerts a mitigating influence on KA induced epilepsy model. DBS in the ZI showed anti-seizure effects at low frequency spectrum, with 5 Hz exhibiting optimal efficacy. The low-frequency DBS significantly increased the calcium activities of ZI GABAergic neurons. Furthermore, selective ablation of ZI GABAergic neurons with taCasp3 blocked the anti-seizure effect of low-frequency DBS, indicating the anti-seizure effect of DBS is mediated by the activation of ZI GABAergic neurons. CONCLUSION Our results demonstrate that low-frequency DBS in the ZI attenuates seizure via driving GABAergic neuronal activity. This suggests that the ZI represents a potential DBS target for treating both hippocampal and cortical seizure through the activation of GABAergic neurons, thereby holding therapeutic significance for seizure treatment.
Collapse
Affiliation(s)
- Mengdi Zhang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China; Zhejiang Rehabilitation Medical Center, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Lin Yang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China; First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Zhongxia Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Fan Fei
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Yuan Zhou
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Dongxiao Jiang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Yuyi Zheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Hui Cheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Yu Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Jiajia Fang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital & Forth Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Shuang Wang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital & Forth Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China; Epilepsy Center, Department of Neurology, Second Affiliated Hospital & Forth Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China.
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China; Zhejiang Rehabilitation Medical Center, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, PR China; Epilepsy Center, Department of Neurology, Second Affiliated Hospital & Forth Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China.
| |
Collapse
|
6
|
Weiss SA, Fried I, Engel J, Bragin A, Wang S, Sperling MR, Wong RK, Nir Y, Staba RJ. Pathological neurons generate ripples at the UP-DOWN transition disrupting information transfer. Epilepsia 2024; 65:362-377. [PMID: 38041560 PMCID: PMC10922301 DOI: 10.1111/epi.17845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/03/2023]
Abstract
OBJECTIVE To confirm and investigate why pathological high-frequency oscillations (pHFOs), including ripples (80-200 Hz) and fast ripples (200-600 Hz), are generated during the UP-DOWN transition of the slow wave and if information transmission mediated by ripple temporal coupling is disrupted in the seizure-onset zone (SOZ). METHODS We isolated 217 total units from 175.95 intracranial electroencephalography (iEEG) contact-hours of synchronized macro- and microelectrode recordings from 6 patients. Sleep slow oscillation (.1-2 Hz) epochs were identified in the iEEG recording. iEEG HFOs that occurred superimposed on the slow wave were transformed to phasors and adjusted by the phase of maximum firing in nearby units (i.e., maximum UP). We tested whether, in the SOZ, HFOs and associated action potentials (APs) occur more often at the UP-DOWN transition. We also examined ripple temporal correlations using cross-correlograms. RESULTS At the group level in the SOZ, HFO and HFO-associated AP probability was highest during the UP-DOWN transition of slow wave excitability (p < < .001). In the non-SOZ, HFO and HFO-associated AP was highest during the DOWN-UP transition (p < < .001). At the unit level in the SOZ, 15.6% and 20% of units exhibited more robust firing during ripples (Cohen's d = .11-.83) and fast ripples (d = .36-.90) at the UP-DOWN transition (p < .05 f.d.r. corrected), respectively. By comparison, also in the SOZ, 6.6% (d = .14-.30) and 8.5% (d = .33-.41) of units had significantly less firing during ripples and fast ripples at the UP-DOWN transition, respectively. Additional data shows that ripple and fast ripple temporal correlations, involving global slow waves, between the hippocampus, entorhinal cortex, and parahippocampal gyrus were reduced by >50% in the SOZ compared to the non-SOZ (N = 3). SIGNIFICANCE The UP-DOWN transition of slow wave excitability facilitates the activation of pathological neurons to generate pHFOs. Ripple temporal correlations across brain regions may be important in memory consolidation and are disrupted in the SOZ, perhaps by pHFO generation.
Collapse
Affiliation(s)
- Shennan A Weiss
- Dept. of Neurology, State University of New York Downstate, Brooklyn, New York, 11203 USA
- Dept. of Physiology and Pharmacology, State University of New York Downstate, Brooklyn, New York, 11203 USA
- Dept. of Neurology, New York City Health + Hospitals/Kings County, Brooklyn, NY, USA
| | - Itzhak Fried
- Dept. of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| | - Jerome Engel
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| | - Anatol Bragin
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| | - Shuang Wang
- Depts of Neurology, Epilepsy Center, Second Affiliated Hospital of Medical College, Zhejiang University, Zhejiang, China
| | - Michael R. Sperling
- Depts. of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, USA
| | - Robert K.S. Wong
- Dept. of Physiology and Pharmacology, State University of New York Downstate, Brooklyn, New York, 11203 USA
| | - Yuval Nir
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
- The Sieratzki-Sagol Center for Sleep Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv 6423906, Israel
| | - Richard J Staba
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| |
Collapse
|
7
|
Guo F, Li A, Liu Q, Guo D, Chen K, Yao D, Cui Y, Xia Y. Disruption of TLE epileptiform activity retarded the seizure and reduced pathological HFOs. Brain Res Bull 2024; 207:110869. [PMID: 38184151 DOI: 10.1016/j.brainresbull.2024.110869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/17/2023] [Accepted: 01/01/2024] [Indexed: 01/08/2024]
Abstract
In temporal lobe epilepsy (TLE), the epileptogenic zones, such as the temporal lobe structure, could generate pathological high-frequency oscillations (pHFOs, 250-500 Hz) before the ictal period. These pHFOs have also been observed during the process of seizures in both TLE patients and animals, exhibiting a critical role as promising biomarkers for TLE seizures. TLE seizures could be modulated via regulating the neural excitability in epileptogenic zones, for that TLE is primarily associated with the excitation-inhibition imbalance. However, whether these kinds of modulations could also impact the pHFOs characteristics during TLE seizures is still unclear. For this purpose, we pharmaco-genetically inhibited the principal cells (PCs) in the mouse CA3 region and tracked the difference in the behavioral and electrophysiological features during LiCl-pilocarpine-induced TLE seizure between the hM4Di+CNO (experimental) mice and mCherry+CNO (control) mice. Delayed latency, decreased averaged duration, and reduced counts of the generalized seizure were observed in the experimental mice. Besides, the electrophysiological characteristics, such as the firing rate of PCs and the count of pHFO, exhibited significant decline in the CA3 and CA1 regions. During TLE seizure, there existed strong phase-coupling between pHFO and PCs spike timing in the control mice, while it was abolished in the experimental mice. In addition, we also found that the counts of pHFO were significantly associated with the behavioral features, indicating the close relationships within them. Collectively, our findings suggested that alterations in pHFO and the retardation of seizures may be attributed to disruptions in neuronal excitability, and the variations of electrophysiological features were related to seizure severity during TLE seizures. These results provide valuable insights into the role of pHFOs in TLE and shed light on the underlying mechanisms involved.
Collapse
Affiliation(s)
- Fengru Guo
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Airui Li
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Qinjun Liu
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Daqing Guo
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Ke Chen
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Dezhong Yao
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yan Cui
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China.
| | - Yang Xia
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China.
| |
Collapse
|
8
|
Guo F, Cui Y, Li A, Liu M, Jian Z, Chen K, Yao D, Guo D, Xia Y. Differential patterns of very high-frequency oscillations in two seizure types of the pilocarpine-induced TLE model. Brain Res Bull 2023; 204:110805. [PMID: 37925081 DOI: 10.1016/j.brainresbull.2023.110805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 10/08/2023] [Accepted: 10/30/2023] [Indexed: 11/06/2023]
Abstract
AIMS Very high-frequency oscillations (VHFOs, >500 Hz) are considered a highly sensitive biomarker of seizures. We hypothesized that VHFOs may exhibit specificity towards hypersynchronous (HYP) seizures and low-voltage fast (LVF) seizures in temporal lobe epilepsy (TLE). METHODS Local field potentials were recorded from the hippocampal network in TLE mice induced by pilocarpine. Subsequently, we analyzed the VHFO features, including their temporal-frequency characteristics and VHFO/theta coupling, during three states: baseline, preictal, and postictal for both HYP- and LVF-seizure groups. RESULTS Significant changes in most of the VHFO features were observed during the preictal state in both seizure groups. In the postictal state, VHFO features in the HYP-seizure group exhibited inverse alterations and appeared to align with those observed during baseline conditions. However, such phenomena were not observed after TLE seizures in the LVF-seizure group. CONCLUSION Our findings highlight distinct patterns of VHFO feature changes across different states of HYP seizures and LVF seizures. These results suggest that VHFOs could serve as indicative biomarkers for seizure alterations specifically associated with HYP-seizure states.
Collapse
Affiliation(s)
- Fengru Guo
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yan Cui
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China.
| | - Airui Li
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Mingqi Liu
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhaoxin Jian
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Ke Chen
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Dezhong Yao
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Daqing Guo
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yang Xia
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China.
| |
Collapse
|
9
|
Wang S, Lévesque M, Fisher TAJ, Kennedy TE, Avoli M. CA3 principal cell activation triggers hypersynchronous-onset seizures in a mouse model of mesial temporal lobe epilepsy. J Neurophysiol 2023; 130:1041-1052. [PMID: 37703488 DOI: 10.1152/jn.00244.2023] [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: 06/20/2023] [Revised: 09/13/2023] [Accepted: 09/13/2023] [Indexed: 09/15/2023] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common form of focal epilepsy and it is characterized by seizures that are often refractory to medications. Seizures in MTLE have two main patterns of onset that have been termed hypersynchronous (HYP) and low-voltage fast (LVF) and are believed to mainly depend on the activity of excitatory principal cells and inhibitory interneurons, respectively. In this study, we investigated whether unilateral open-loop optogenetic activation of CaMKII-positive principal cells in the hippocampus CA3 region favors the generation of spontaneous HYP seizures in kainic acid-treated (KA) CaMKII-ChR2 mice. Optogenetic activation of CA3 principal cells (1 Hz, 180 s ON, 220 s OFF) was implemented for 15 days after KA-induced status epilepticus. We found that both LVF and HYP seizures occurred in nonstimulated CaMKII-ChR2 (n = 6) and stimulated CaMKII-Cre (n = 5) mice. In contrast, optogenetic activation of principal cells in CaMKII-ChR2 mice (n = 5) triggered only HYP seizures that were characterized by high fast ripple (250-500 Hz) rates during the pre-ictal and ictal periods. These results provide firm evidence that in MTLE spontaneous seizures with different onset patterns depend on distinct neuronal network mechanisms of generation. They also demonstrate that HYP seizures occurring in vivo along with their associated fast ripples depend on the activity of principal cells in the CA3 region.NEW & NOTEWORTHY Previous evidence suggested that different seizure onset patterns rely on the activity of distinct neuronal populations. In this study, we show for the first time that in vivo optogenetic stimulation of CaMKII principal cells in kainic acid-treated mice triggers hypersynchronous-onset seizures that are associated with fast ripples. Our findings indicate that in patients with predominant HYP-onset seizures, anticonvulsant treatments should be aimed at limiting the firing of principal neurons in the seizure onset zone.
Collapse
Affiliation(s)
- Siyan Wang
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
| | - Maxime Lévesque
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
| | - Teddy A J Fisher
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
| | - Timothy E Kennedy
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
| | - Massimo Avoli
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
- Department of Physiology, McGill University, Montréal, Quebec, Canada
| |
Collapse
|
10
|
Weiss SA, Fried I, Engel J, Sperling MR, Wong RKS, Nir Y, Staba RJ. Fast ripples reflect increased excitability that primes epileptiform spikes. Brain Commun 2023; 5:fcad242. [PMID: 37869578 PMCID: PMC10587774 DOI: 10.1093/braincomms/fcad242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/08/2023] [Accepted: 09/07/2023] [Indexed: 10/24/2023] Open
Abstract
The neuronal circuit disturbances that drive inter-ictal and ictal epileptiform discharges remain elusive. Using a combination of extra-operative macro-electrode and micro-electrode inter-ictal recordings in six pre-surgical patients during non-rapid eye movement sleep, we found that, exclusively in the seizure onset zone, fast ripples (200-600 Hz), but not ripples (80-200 Hz), frequently occur <300 ms before an inter-ictal intra-cranial EEG spike with a probability exceeding chance (bootstrapping, P < 1e-5). Such fast ripple events are associated with higher spectral power (P < 1e-10) and correlated with more vigorous neuronal firing than solitary fast ripple (generalized linear mixed-effects model, P < 1e-9). During the intra-cranial EEG spike that follows a fast ripple, action potential firing is lower than during an intra-cranial EEG spike alone (generalized linear mixed-effects model, P < 0.05), reflecting an inhibitory restraint of intra-cranial EEG spike initiation. In contrast, ripples do not appear to prime epileptiform spikes. We next investigated the clinical significance of pre-spike fast ripple in a separate cohort of 23 patients implanted with stereo EEG electrodes, who underwent resections. In non-rapid eye movement sleep recordings, sites containing a high proportion of fast ripple preceding intra-cranial EEG spikes correlate with brain areas where seizures begin more than solitary fast ripple (P < 1e-5). Despite this correlation, removal of these sites does not guarantee seizure freedom. These results are consistent with the hypothesis that fast ripple preceding EEG spikes reflect an increase in local excitability that primes EEG spike discharges preferentially in the seizure onset zone and that epileptogenic brain regions are necessary, but not sufficient, for initiating inter-ictal epileptiform discharges.
Collapse
Affiliation(s)
- Shennan A Weiss
- Department of Neurology, State University of New York Downstate, Brooklyn, NY 11203, USA
- Department of Physiology and Pharmacology, State University of New York Downstate, Brooklyn, NY 11203, USA
- Department of Neurology, New York City Health + Hospitals/Kings County, Brooklyn, NY 11203, USA
| | - Itzhak Fried
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Jerome Engel
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Michael R Sperling
- Departments of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Robert K S Wong
- Department of Physiology and Pharmacology, State University of New York Downstate, Brooklyn, NY 11203, USA
| | - Yuval Nir
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
- The Sieratzki-Sagol Center for Sleep Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv 6423906, Israel
| | - Richard J Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| |
Collapse
|
11
|
Frauscher B, Bénar CG, Engel JJ, Grova C, Jacobs J, Kahane P, Wiebe S, Zjilmans M, Dubeau F. Neurophysiology, Neuropsychology, and Epilepsy, in 2022: Hills We Have Climbed and Hills Ahead. Neurophysiology in epilepsy. Epilepsy Behav 2023; 143:109221. [PMID: 37119580 DOI: 10.1016/j.yebeh.2023.109221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 05/01/2023]
Abstract
Since the discovery of the human electroencephalogram (EEG), neurophysiology techniques have become indispensable tools in our armamentarium to localize epileptic seizures. New signal analysis techniques and the prospects of artificial intelligence and big data will offer unprecedented opportunities to further advance the field in the near future, ultimately resulting in improved quality of life for many patients with drug-resistant epilepsy. This article summarizes selected presentations from Day 1 of the two-day symposium "Neurophysiology, Neuropsychology, Epilepsy, 2022: Hills We Have Climbed and the Hills Ahead". Day 1 was dedicated to highlighting and honoring the work of Dr. Jean Gotman, a pioneer in EEG, intracranial EEG, simultaneous EEG/ functional magnetic resonance imaging, and signal analysis of epilepsy. The program focused on two main research directions of Dr. Gotman, and was dedicated to "High-frequency oscillations, a new biomarker of epilepsy" and "Probing the epileptic focus from inside and outside". All talks were presented by colleagues and former trainees of Dr. Gotman. The extended summaries provide an overview of historical and current work in the neurophysiology of epilepsy with emphasis on novel EEG biomarkers of epilepsy and source imaging and concluded with an outlook on the future of epilepsy research, and what is needed to bring the field to the next level.
Collapse
Affiliation(s)
- B Frauscher
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada.
| | - C G Bénar
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - J Jr Engel
- David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - C Grova
- Multimodal Functional Imaging Lab, PERFORM Centre, Department of Physics, Concordia University, Montreal, QC, Canada; Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, QC, Canada; Montreal Neurological Institute and Hospital, Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
| | - J Jacobs
- Department of Pediatric and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - P Kahane
- Univ. Grenoble Alpes, Inserm, U1216, CHU Grenoble Alpes, Grenoble Institute Neurosciences, Department of Neurology, 38000 Grenoble, France
| | - S Wiebe
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
| | - M Zjilmans
- Stichting Epilepsie Instellingen Nederland, The Netherlands; Brain Center, University Medical Center Utrecht, The Netherlands
| | - F Dubeau
- Montreal Neurological Institute and Hospital, Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
| |
Collapse
|
12
|
Weiss SA, Fried I, Engel J, Sperling MR, Wong RK, Nir Y, Staba RJ. Fast ripples reflect increased excitability that primes epileptiform spikes. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.26.23287702. [PMID: 37034609 PMCID: PMC10081394 DOI: 10.1101/2023.03.26.23287702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The neuronal circuit disturbances that drive interictal and ictal epileptiform discharges remains elusive. Using a combination of extraoperative macro- and micro-electrode interictal recordings in six presurgical patients during non-rapid eye movement (REM) sleep we found that, exclusively in the seizure onset zone, fast ripples (FR; 200-600Hz), but not ripples (80-200 Hz), frequently occur <300 msec before an interictal intracranial EEG (iEEG) spike with a probability exceeding chance (bootstrapping, p<1e-5). Such FR events are associated with higher spectral power (p<1e-10) and correlated with more vigorous neuronal firing than solitary FR (generalized linear mixed-effects model, GLMM, p<1e-3) irrespective of FR power. During the iEEG spike that follows a FR, action potential firing is lower than during a iEEG spike alone (GLMM, p<1e-10), reflecting an inhibitory restraint of iEEG spike initiation. In contrast, ripples do not appear to prime epileptiform spikes. We next investigated the clinical significance of pre-spike FR in a separate cohort of 23 patients implanted with stereo EEG electrodes who underwent resections. In non-REM sleep recordings, sites containing a high proportion of FR preceding iEEG spikes correlate with brain areas where seizures begin more than solitary FR (p<1e-5). Despite this correlation, removal of these sites does not guarantee seizure freedom. These results are consistent with the hypothesis that FR preceding EEG spikes reflect an increase in local excitability that primes EEG spike discharges preferentially in the seizure onset zone and that epileptogenic brain regions are necessary, but not sufficient, for initiating interictal epileptiform discharges.
Collapse
Affiliation(s)
- Shennan A Weiss
- Dept. of Neurology, State University of New York Downstate, Brooklyn, New York, 11203 USA
- Dept. of Physiology and Pharmacology, State University of New York Downstate, Brooklyn, New York, 11203 USA
- Dept. of Neurology, New York City Health + Hospitals/Kings County, Brooklyn, NY, USA
| | - Itzhak Fried
- Dept. of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| | - Jerome Engel
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| | - Michael R. Sperling
- Depts. of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, USA
| | - Robert K.S. Wong
- Dept. of Physiology and Pharmacology, State University of New York Downstate, Brooklyn, New York, 11203 USA
| | - Yuval Nir
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
- The Sieratzki-Sagol Center for Sleep Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv 6423906, Israel
| | - Richard J Staba
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| |
Collapse
|
13
|
Avoli M, Chen LY, Di Cristo G, Librizzi L, Scalmani P, Shiri Z, Uva L, de Curtis M, Lévesque M. Ligand-gated mechanisms leading to ictogenesis in focal epileptic disorders. Neurobiol Dis 2023; 180:106097. [PMID: 36967064 DOI: 10.1016/j.nbd.2023.106097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/14/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
We review here the neuronal mechanisms that cause seizures in focal epileptic disorders and, specifically, those involving limbic structures that are known to be implicated in human mesial temporal lobe epilepsy. In both epileptic patients and animal models, the initiation of focal seizures - which are most often characterized by a low-voltage fast onset EEG pattern - is presumably dependent on the synchronous firing of GABA-releasing interneurons that, by activating post-synaptic GABAA receptors, cause large increases in extracellular [K+] through the activation of the co-transporter KCC2. A similar mechanism may contribute to seizure maintenance; accordingly, inhibiting KCC2 activity transforms seizure activity into a continuous pattern of short-lasting epileptiform discharges. It has also been found that interactions between different areas of the limbic system modulate seizure occurrence by controlling extracellular [K+] homeostasis. In line with this view, low-frequency electrical or optogenetic activation of limbic networks restrain seizure generation, an effect that may also involve the activation of GABAB receptors and activity-dependent changes in epileptiform synchronization. Overall, these findings highlight the paradoxical role of GABAA signaling in both focal seizure generation and maintenance, emphasize the efficacy of low-frequency activation in abating seizures, and provide experimental evidence explaining the poor efficacy of antiepileptic drugs designed to augment GABAergic function in controlling seizures in focal epileptic disorders.
Collapse
Affiliation(s)
- Massimo Avoli
- Montreal Neurological Institute-Hospital, Departments of Neurology, Canada; Neurology & Neurosurgery and of Physiology, McGill University, Montreal H3A 2B4, Que, Canada.
| | - Li-Yuan Chen
- Montreal Neurological Institute-Hospital, Departments of Neurology, Canada
| | - Graziella Di Cristo
- Neurosciences Department, Université de Montréal, Montréal, Québec H3T 1N8, Canada; CHU Sainte-Justine Research Center, Montréal, Québec H3T 1C5, Canada
| | - Laura Librizzi
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Paolo Scalmani
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Zahra Shiri
- Montreal Neurological Institute-Hospital, Departments of Neurology, Canada
| | - Laura Uva
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Maxime Lévesque
- Montreal Neurological Institute-Hospital, Departments of Neurology, Canada
| |
Collapse
|
14
|
Kim E, Kim HC, Van Reet J, Böhlke M, Yoo SS, Lee W. Transcranial focused ultrasound-mediated unbinding of phenytoin from plasma proteins for suppression of chronic temporal lobe epilepsy in a rodent model. Sci Rep 2023; 13:4128. [PMID: 36914775 PMCID: PMC10011522 DOI: 10.1038/s41598-023-31383-4] [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: 11/25/2022] [Accepted: 03/10/2023] [Indexed: 03/16/2023] Open
Abstract
The efficacy of many anti-epileptic drugs, including phenytoin (PHT), is reduced by plasma protein binding (PPB) that sequesters therapeutically active drug molecules within the bloodstream. An increase in systemic dose elevates the risk of drug side effects, which demands an alternative technique to increase the unbound concentration of PHT in a region-specific manner. We present a low-intensity focused ultrasound (FUS) technique that locally enhances the efficacy of PHT by transiently disrupting its binding to albumin. We first identified the acoustic parameters that yielded the highest PHT unbinding from albumin among evaluated parameter sets using equilibrium dialysis. Then, rats with chronic mesial temporal lobe epilepsy (mTLE) received four sessions of PHT injection, each followed by 30 min of FUS delivered to the ictal region, across 2 weeks. Two additional groups of mTLE rats underwent the same procedure, but without receiving PHT or FUS. Assessment of electrographic seizure activities revealed that FUS accompanying administration of PHT effectively reduced the number and mean duration of ictal events compared to other conditions, without damaging brain tissue or the blood-brain barrier. Our results demonstrated that the FUS technique enhanced the anti-epileptic efficacy of PHT in a chronic mTLE rodent model by region-specific PPB disruption.
Collapse
Affiliation(s)
- Evgenii Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Hyun-Chul Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
- Department of Artificial Intelligence, Kyungpook National University, Daegu, South Korea
| | - Jared Van Reet
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Mark Böhlke
- Massachusetts College of Pharmacy and Health Sciences University, Boston, MA, USA
| | - Seung-Schik Yoo
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Wonhye Lee
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
| |
Collapse
|
15
|
Lai N, Li Z, Xu C, Wang Y, Chen Z. Diverse nature of interictal oscillations: EEG-based biomarkers in epilepsy. Neurobiol Dis 2023; 177:105999. [PMID: 36638892 DOI: 10.1016/j.nbd.2023.105999] [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: 12/02/2022] [Revised: 01/07/2023] [Accepted: 01/09/2023] [Indexed: 01/11/2023] Open
Abstract
Interictal electroencephalogram (EEG) patterns, including high-frequency oscillations (HFOs), interictal spikes (ISs), and slow wave activities (SWAs), are defined as specific oscillations between seizure events. These interictal oscillations reflect specific dynamic changes in network excitability and play various roles in epilepsy. In this review, we briefly describe the electrographic characteristics of HFOs, ISs, and SWAs in the interictal state, and discuss the underlying cellular and network mechanisms. We also summarize representative evidence from experimental and clinical epilepsy to address their critical roles in ictogenesis and epileptogenesis, indicating their potential as electrophysiological biomarkers of epilepsy. Importantly, we put forwards some perspectives for further research in the field.
Collapse
Affiliation(s)
- Nanxi Lai
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhisheng Li
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China; Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| |
Collapse
|
16
|
Chloride ion dysregulation in epileptogenic neuronal networks. Neurobiol Dis 2023; 177:106000. [PMID: 36638891 DOI: 10.1016/j.nbd.2023.106000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/25/2022] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
GABA is the major inhibitory neurotransmitter in the mature CNS. When GABAA receptors are activated the membrane potential is driven towards hyperpolarization due to chloride entry into the neuron. However, chloride ion dysregulation that alters the ionic gradient can result in depolarizing GABAergic post-synaptic potentials instead. In this review, we highlight that GABAergic inhibition prevents and restrains focal seizures but then reexamine this notion in the context of evidence that a static and/or a dynamic chloride ion dysregulation, that increases intracellular chloride ion concentrations, promotes epileptiform activity and seizures. To reconcile these findings, we hypothesize that epileptogenic pathologically interconnected neuron (PIN) microcircuits, representing a small minority of neurons, exhibit static chloride dysregulation and should exhibit depolarizing inhibitory post-synaptic potentials (IPSPs). We speculate that chloride ion dysregulation and PIN cluster activation may generate fast ripples and epileptiform spikes as well as initiate the hypersynchronous seizure onset pattern and microseizures. Also, we discuss the genetic, molecular, and cellular players important in chloride dysregulation which regulate epileptogenesis and initiate the low-voltage fast seizure onset pattern. We conclude that chloride dysregulation in neuronal networks appears to be critical for epileptogenesis and seizure genesis, but feed-back and feed-forward inhibitory GABAergic neurotransmission plays an important role in preventing and restraining seizures as well.
Collapse
|
17
|
Weiss SA, Fried I, Wu C, Sharan A, Rubinstein D, Engel J, Sperling MR, Staba RJ. Graph theoretical measures of fast ripple networks improve the accuracy of post-operative seizure outcome prediction. Sci Rep 2023; 13:367. [PMID: 36611059 PMCID: PMC9825369 DOI: 10.1038/s41598-022-27248-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 12/28/2022] [Indexed: 01/09/2023] Open
Abstract
Fast ripples (FR) are a biomarker of epileptogenic brain, but when larger portions of FR generating regions are resected seizure freedom is not always achieved. To evaluate and improve the diagnostic accuracy of FR resection for predicting seizure freedom we compared the FR resection ratio (RR) with FR network graph theoretical measures. In 23 patients FR were semi-automatically detected and quantified in stereo EEG recordings during sleep. MRI normalization and co-registration localized contacts and relation to resection margins. The number of FR, and graph theoretical measures, which were spatial (i.e., FR rate-distance radius) or temporal correlational (i.e., FR mutual information), were compared with the resection margins and with seizure outcome We found that the FR RR did not correlate with seizure-outcome (p > 0.05). In contrast, the FR rate-distance radius resected difference and the FR MI mean characteristic path length RR did correlate with seizure-outcome (p < 0.05). Retesting of positive FR RR patients using either FR rate-distance radius resected difference or the FR MI mean characteristic path length RR reduced seizure-free misclassifications from 44 to 22% and 17%, respectively. These results indicate that graph theoretical measures of FR networks can improve the diagnostic accuracy of the resection of FR events for predicting seizure freedom.
Collapse
Affiliation(s)
- Shennan A. Weiss
- grid.262863.b0000 0001 0693 2202Department of Neurology, State University of New York Downstate, Brooklyn, USA ,grid.262863.b0000 0001 0693 2202Department of Physiology and Pharmacology, State University of New York Downstate, 450 Clarkson Avenue, MSC 1213, Brooklyn, NY 11203 USA ,grid.422616.50000 0004 0443 7226Department of Neurology, New York City Health + Hospitals/Kings County, Brooklyn, NY USA
| | - Itzhak Fried
- grid.19006.3e0000 0000 9632 6718Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, USA
| | - Chengyuan Wu
- grid.265008.90000 0001 2166 5843Department of Neuroradiology, Thomas Jefferson University, Philadelphia, USA ,grid.265008.90000 0001 2166 5843Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA 19107 USA
| | - Ashwini Sharan
- grid.265008.90000 0001 2166 5843Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA 19107 USA
| | - Daniel Rubinstein
- grid.265008.90000 0001 2166 5843Department of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, USA
| | - Jerome Engel
- grid.19006.3e0000 0000 9632 6718Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, USA ,grid.19006.3e0000 0000 9632 6718Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, USA ,grid.19006.3e0000 0000 9632 6718Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, USA ,grid.19006.3e0000 0000 9632 6718Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, USA ,grid.19006.3e0000 0000 9632 6718David Geffen School of Medicine at UCLA, Brain Research Institute, Los Angeles, CA 90095 USA
| | - Michael R. Sperling
- grid.265008.90000 0001 2166 5843Department of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, USA
| | - Richard J. Staba
- grid.19006.3e0000 0000 9632 6718Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, USA
| |
Collapse
|
18
|
Kang W, Ju C, Joo J, Lee J, Shon YM, Park SM. Closed-loop direct control of seizure focus in a rodent model of temporal lobe epilepsy via localized electric fields applied sequentially. Nat Commun 2022; 13:7805. [PMID: 36528681 PMCID: PMC9759546 DOI: 10.1038/s41467-022-35540-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
Direct electrical stimulation of the seizure focus can achieve the early termination of epileptic oscillations. However, direct intervention of the hippocampus, the most prevalent seizure focus in temporal lobe epilepsy is thought to be not practicable due to its large size and elongated shape. Here, in a rat model, we report a sequential narrow-field stimulation method for terminating seizures, while focusing stimulus energy at the spatially extensive hippocampal structure. The effects and regional specificity of this method were demonstrated via electrophysiological and biological responses. Our proposed modality demonstrates spatiotemporal preciseness and selectiveness for modulating the pathological target region which may have potential for further investigation as a therapeutic approach.
Collapse
Affiliation(s)
- Wonok Kang
- grid.49100.3c0000 0001 0742 4007School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Chanyang Ju
- grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Jaesoon Joo
- grid.264381.a0000 0001 2181 989XBiomedical Engineering Research Center, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 South Korea
| | - Jiho Lee
- grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Young-Min Shon
- grid.264381.a0000 0001 2181 989XBiomedical Engineering Research Center, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 South Korea ,grid.264381.a0000 0001 2181 989XDepartment of Neurology, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 Republic of Korea
| | - Sung-Min Park
- grid.49100.3c0000 0001 0742 4007School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Electrical Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.15444.300000 0004 0470 5454Institute of Convergence Science, Yonsei University, Seoul, 03722 Republic of Korea
| |
Collapse
|
19
|
Barrett KT, Choudhary A, Charkhand B, Scantlebury MH. Animal Models in Epileptic Spasms and the Development of Novel Treatment Options. J Clin Neurophysiol 2022; 39:529-537. [PMID: 35323127 DOI: 10.1097/wnp.0000000000000496] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY The infantile spasms (IS) syndrome is a catastrophic developmental epileptic encephalopathy syndrome characterized by an age-specific expression of epileptic spasms that are associated with extremely abnormal, oftentimes described as chaotic, interictal EEG pattern known as hypsarrhythmia. Patients with IS generally have poor neurodevelopmental outcomes, in large part because of the frequent epileptic spasms and interictal EEG abnormalities. Current first-line treatments such as adrenocorticotropic hormone or vigabatrin are often ineffective and are associated with major toxic side effects. There is therefore a need for better and safer treatments for patients with IS, especially for the intractable population. Hope is on the horizon as, over the past 10 years, there has been robust progress in the development of etiology-specific animal models of IS. These models have been used to identify potential new treatments for IS and are beginning to provide some important insights into the pathophysiological substrates for this disease. In this review, we will highlight strengths and weaknesses of the currently available animal models of IS in addition to new insights into the pathophysiology and treatment options derived from these models.
Collapse
Affiliation(s)
- Karlene T Barrett
- Department of Pediatrics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; and
| | - Anamika Choudhary
- Department of Pediatrics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; and
| | - Behshad Charkhand
- Department of Pediatrics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; and
| | - Morris H Scantlebury
- Department of Pediatrics, Clinical Neurosciences, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
20
|
Aquatic Freshwater Vertebrate Models of Epilepsy Pathology: Past Discoveries and Future Directions for Therapeutic Discovery. Int J Mol Sci 2022; 23:ijms23158608. [PMID: 35955745 PMCID: PMC9368815 DOI: 10.3390/ijms23158608] [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: 05/06/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 12/04/2022] Open
Abstract
Epilepsy is an international public health concern that greatly affects patients’ health and lifestyle. About 30% of patients do not respond to available therapies, making new research models important for further drug discovery. Aquatic vertebrates present a promising avenue for improved seizure drug screening and discovery. Zebrafish (Danio rerio) and African clawed frogs (Xenopus laevis and tropicalis) are increasing in popularity for seizure research due to their cost-effective housing and rearing, similar genome to humans, ease of genetic manipulation, and simplicity of drug dosing. These organisms have demonstrated utility in a variety of seizure-induction models including chemical and genetic methods. Past studies with these methods have produced promising data and generated questions for further applications of these models to promote discovery of drug-resistant seizure pathology and lead to effective treatments for these patients.
Collapse
|
21
|
Chu PC, Yu HY, Lee CC, Fisher R, Liu HL. Pulsed-Focused Ultrasound Provides Long-Term Suppression of Epileptiform Bursts in the Kainic Acid-Induced Epilepsy Rat Model. Neurotherapeutics 2022; 19:1368-1380. [PMID: 35581489 PMCID: PMC9587190 DOI: 10.1007/s13311-022-01250-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2022] [Indexed: 10/18/2022] Open
Abstract
Focused ultrasound (FUS) has potential utility for modulating regional brain excitability and possibly aiding seizure control; however, the duration of any beneficial effect is unknown. This study explores the efficacy and time course of a short series of pulsed FUS in suppressing EEG epileptiform spikes/bursts in a kainic acid (KA) animal model of temporal lobe epilepsy. Forty-four male Sprague-Dawley rats were recorded for 14 weeks with EEG while software calculated EEG numbers of epileptiform spikes and bursts (≥ 3 spikes/s). Four regimens of FUS given in a single session at week 7 were evaluated, with mechanical index (MI) ranging from 0.25 to 0.75, intensity spatial peak temporal average (ISPTA) from 0.1 to 2.8 W per cm2, duty cycle from 1 to 30%, and three consecutive pulse trains for 5 or 10 min each. Controls included sham injections in four and KA without FUS in eleven animals. Histological analysis investigated tissue effects. All animals receiving KA evidenced EEG spikes, averaging 10,378 ± 1651 spikes per 8 h and 1255 ± 199 bursts per 8 h by weeks 6-7. The KA-only group showed a 30% of increase in spikes and bursts by week 14. Compared to the KA-only group, spike counts were reduced by about 25%, burst counts by about 33%, and burst durations by about 50% with FUS. Behavioral seizures were not analyzed, but electrographic seizures longer than 10 s declined up to 70% after some FUS regimens. Repeated-measure ANOVA showed a significant effect of higher intensity and longer sonication duration FUS treatment using 0.75-MI, ISPTA 2.8 W/cm2, 30% duty cycle for 10-min sonications (group effect, F (4, 15) = 6.321, p < 0.01; interaction effect, F (44, 165) = 1.726, p < 0.01), with the hippocampal protective effect lasting to week 14, accompanied by decreased inflammation and gliosis effect. In contrast, spike and burst suppression were achieved using an FUS regimen with 0.25-MI ISPTA 0.5 W/cm2, 30% duty cycle for 10-min sonications. This regimen reduced inflammation and gliosis at weeks 8-14 and protected hippocampal tissue. This study demonstrates that low-intensity pulsed ultrasound can modulate epileptiform activity for up to 7 weeks and, if replicated in the clinical setting, might be a practical treatment for epilepsy.
Collapse
Affiliation(s)
- Po-Chun Chu
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, 106
| | - Hsiang-Yu Yu
- Department of Neurology, Taipei Veteran General Hospital, Taipei, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Cheng-Chia Lee
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Department of Neurosurgery, Taipei Veteran General Hospital, Taipei, Taiwan
| | - Robert Fisher
- Department of Neurology, Stanford Neuroscience Health Center, Stanford University School of Medicine, 213 Quarry Road, Room 4865, Palo Alto, CA, 94304-5979, USA.
| | - Hao-Li Liu
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, 106.
| |
Collapse
|
22
|
Lisgaras CP, Scharfman HE. Robust chronic convulsive seizures, high frequency oscillations, and human seizure onset patterns in an intrahippocampal kainic acid model in mice. Neurobiol Dis 2022; 166:105637. [PMID: 35091040 PMCID: PMC9034729 DOI: 10.1016/j.nbd.2022.105637] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 01/05/2022] [Accepted: 01/22/2022] [Indexed: 01/21/2023] Open
Abstract
Intrahippocampal kainic acid (IHKA) has been widely implemented to simulate temporal lobe epilepsy (TLE), but evidence of robust seizures is usually limited. To resolve this problem, we slightly modified previous methods and show robust seizures are common and frequent in both male and female mice. We employed continuous wideband video-EEG monitoring from 4 recording sites to best demonstrate the seizures. We found many more convulsive seizures than most studies have reported. Mortality was low. Analysis of convulsive seizures at 2-4 and 10-12 wks post-IHKA showed a robust frequency (2-4 per day on average) and duration (typically 20-30 s) at each time. Comparison of the two timepoints showed that seizure burden became more severe in approximately 50% of the animals. We show that almost all convulsive seizures could be characterized as either low-voltage fast or hypersynchronous onset seizures, which has not been reported in a mouse model of epilepsy and is important because these seizure types are found in humans. In addition, we report that high frequency oscillations (>250 Hz) occur, resembling findings from IHKA in rats and TLE patients. Pathology in the hippocampus at the site of IHKA injection was similar to mesial temporal lobe sclerosis and reduced contralaterally. In summary, our methods produce a model of TLE in mice with robust convulsive seizures, and there is variable progression. HFOs are robust also, and seizures have onset patterns and pathology like human TLE. SIGNIFICANCE: Although the IHKA model has been widely used in mice for epilepsy research, there is variation in outcomes, with many studies showing few robust seizures long-term, especially convulsive seizures. We present an implementation of the IHKA model with frequent convulsive seizures that are robust, meaning they are >10 s and associated with complex high frequency rhythmic activity recorded from 2 hippocampal and 2 cortical sites. Seizure onset patterns usually matched the low-voltage fast and hypersynchronous seizures in TLE. Importantly, there is low mortality, and both sexes can be used. We believe our results will advance the ability to use the IHKA model of TLE in mice. The results also have important implications for our understanding of HFOs, progression, and other topics of broad interest to the epilepsy research community. Finally, the results have implications for preclinical drug screening because seizure frequency increased in approximately half of the mice after a 6 wk interval, suggesting that the typical 2 wk period for monitoring seizure frequency is insufficient.
Collapse
Affiliation(s)
- Christos Panagiotis Lisgaras
- Departments of Child & Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, and the Neuroscience Institute, New York University Langone Health, 550 First Ave., New York, NY 10016, United States of America,Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, New York State Office of Mental Health, 140 Old Orangeburg Road, Bldg. 35, Orangeburg, NY 10962, United States of America
| | - Helen E. Scharfman
- Departments of Child & Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, and the Neuroscience Institute, New York University Langone Health, 550 First Ave., New York, NY 10016, United States of America,Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, New York State Office of Mental Health, 140 Old Orangeburg Road, Bldg. 35, Orangeburg, NY 10962, United States of America,Corresponding author at: The Nathan Kline Institute, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY 10962, United States of America. (H.E. Scharfman)
| |
Collapse
|
23
|
Weiss SA, Pastore T, Orosz I, Rubinstein D, Gorniak R, Waldman Z, Fried I, Wu C, Sharan A, Slezak D, Worrell G, Engel J, Sperling MR, Staba RJ. Graph theoretical measures of fast ripples support the epileptic network hypothesis. Brain Commun 2022; 4:fcac101. [PMID: 35620169 PMCID: PMC9128387 DOI: 10.1093/braincomms/fcac101] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 02/10/2022] [Accepted: 04/12/2022] [Indexed: 11/16/2022] Open
Abstract
The epileptic network hypothesis and epileptogenic zone hypothesis are two
theories of ictogenesis. The network hypothesis posits that coordinated activity
among interconnected nodes produces seizures. The epileptogenic zone hypothesis
posits that distinct regions are necessary and sufficient for seizure
generation. High-frequency oscillations, and particularly fast ripples, are
thought to be biomarkers of the epileptogenic zone. We sought to test these
theories by comparing high-frequency oscillation rates and networks in surgical
responders and non-responders, with no appreciable change in seizure frequency
or severity, within a retrospective cohort of 48 patients implanted with
stereo-EEG electrodes. We recorded inter-ictal activity during non-rapid eye
movement sleep and semi-automatically detected and quantified high-frequency
oscillations. Each electrode contact was localized in normalized coordinates. We
found that the accuracy of seizure onset zone electrode contact classification
using high-frequency oscillation rates was not significantly different in
surgical responders and non-responders, suggesting that in non-responders the
epileptogenic zone partially encompassed the seizure onset zone(s)
(P > 0.05). We also found that in the
responders, fast ripple on oscillations exhibited a higher spectral content in
the seizure onset zone compared with the non-seizure onset zone
(P < 1 × 10−5).
By contrast, in the non-responders, fast ripple had a lower spectral content in
the seizure onset zone
(P < 1 × 10−5).
We constructed two different networks of fast ripple with a spectral content
>350 Hz. The first was a rate–distance network that
multiplied the Euclidian distance between fast ripple-generating contacts by the
average rate of fast ripple in the two contacts. The radius of the
rate–distance network, which excluded seizure onset zone nodes,
discriminated non-responders, including patients not offered resection or
responsive neurostimulation due to diffuse multifocal onsets, with an accuracy
of 0.77 [95% confidence interval (CI) 0.56–0.98]. The second fast
ripple network was constructed using the mutual information between the timing
of the events to measure functional connectivity. For most non-responders, this
network had a longer characteristic path length, lower mean local efficiency in
the non-seizure onset zone, and a higher nodal strength among non-seizure onset
zone nodes relative to seizure onset zone nodes. The graphical theoretical
measures from the rate–distance and mutual information networks of 22
non- responsive neurostimulation treated patients was used to train a support
vector machine, which when tested on 13 distinct patients classified
non-responders with an accuracy of 0.92 (95% CI 0.75–1). These
results indicate patients who do not respond to surgery or those not selected
for resection or responsive neurostimulation can be explained by the epileptic
network hypothesis that is a decentralized network consisting of widely
distributed, hyperexcitable fast ripple-generating nodes.
Collapse
Affiliation(s)
- Shennan A Weiss
- Dept. of Neurology, State University of New York Downstate, Brooklyn, New York, 11203 USA
- Dept. of Physiology and Pharmacology, State University of New York Downstate, Brooklyn, New York, 11203 USA
- Dept. of Neurology, New York City Health + Hospitals/Kings County, Brooklyn, NY, USA
| | - Tomas Pastore
- Dept. of Computer Science, University of Buenos Aires, Buenos Aires, Argentina
| | - Iren Orosz
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| | - Daniel Rubinstein
- Depts. of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, USA
| | - Richard Gorniak
- Dept. of Neuroradiology, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, USA
| | - Zachary Waldman
- Depts. of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, USA
| | - Itzhak Fried
- Dept. of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| | - Chengyuan Wu
- Dept. of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, USA
| | - Ashwini Sharan
- Dept. of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, USA
| | - Diego Slezak
- Dept. of Computer Science, University of Buenos Aires, Buenos Aires, Argentina
| | - Gregory Worrell
- Dept. of Neurology, Mayo Systems Electrophysiology Laboratory (MSEL), USA
- Dept. of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
| | - Jerome Engel
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Dept. of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
- Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| | - Michael R. Sperling
- Depts. of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, Pennsylvania, 19107, USA
| | - Richard J Staba
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, USA
| |
Collapse
|
24
|
Sánchez-Hernández J, Aguilera P, Manjarrez-Marmolejo J, Franco-Pérez J. Fructose ingestion modifies NMDA receptors and exacerbates the seizures induced by kainic acid. Neurosci Lett 2022; 772:136476. [DOI: 10.1016/j.neulet.2022.136476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/17/2021] [Accepted: 01/20/2022] [Indexed: 12/24/2022]
|
25
|
Twible C, Abdo R, Zhang Q. Astrocyte Role in Temporal Lobe Epilepsy and Development of Mossy Fiber Sprouting. Front Cell Neurosci 2021; 15:725693. [PMID: 34658792 PMCID: PMC8514632 DOI: 10.3389/fncel.2021.725693] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Epilepsy affects approximately 50 million people worldwide, with 60% of adult epilepsies presenting an onset of focal origin. The most common focal epilepsy is temporal lobe epilepsy (TLE). The role of astrocytes in the presentation and development of TLE has been increasingly studied and discussed within the literature. The most common histopathological diagnosis of TLE is hippocampal sclerosis. Hippocampal sclerosis is characterized by neuronal cell loss within the Cornu ammonis and reactive astrogliosis. In some cases, mossy fiber sprouting may be observed. Mossy fiber sprouting has been controversial in its contribution to epileptogenesis in TLE patients, and the mechanisms surrounding the phenomenon have yet to be elucidated. Several studies have reported that mossy fiber sprouting has an almost certain co-existence with reactive astrogliosis within the hippocampus under epileptic conditions. Astrocytes are known to play an important role in the survival and axonal outgrowth of central and peripheral nervous system neurons, pointing to a potential role of astrocytes in TLE and associated cellular alterations. Herein, we review the recent developments surrounding the role of astrocytes in the pathogenic process of TLE and mossy fiber sprouting, with a focus on proposed signaling pathways and cellular mechanisms, histological observations, and clinical correlations in human patients.
Collapse
Affiliation(s)
- Carolyn Twible
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada
| | - Rober Abdo
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Anatomy and Cell Biology, Western University, London, ON, Canada
| | - Qi Zhang
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Pathology and Lab Medicine, London Health Sciences Centre, University Hospital, London, ON, Canada
| |
Collapse
|
26
|
Núñez-Ochoa MA, Chiprés-Tinajero GA, González-Domínguez NP, Medina-Ceja L. Causal relationship of CA3 back-projection to the dentate gyrus and its role in CA1 fast ripple generation. BMC Neurosci 2021; 22:37. [PMID: 34001031 PMCID: PMC8130286 DOI: 10.1186/s12868-021-00641-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 05/07/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Pathophysiological evidence from temporal lobe epilepsy models highlights the hippocampus as the most affected structure due to its high degree of neuroplasticity and control of the dynamics of limbic structures, which are necessary to encode information, conferring to it an intrinsic epileptogenicity. A loss in this control results in observable oscillatory perturbations called fast ripples, in epileptic rats those events are found in CA1, CA3, and the dentate gyrus (DG), which are the principal regions of the trisynaptic circuit of the hippocampus. The present work used Granger causality to address which relationships among these three regions of the trisynaptic circuit are needed to cause fast ripples in CA1 in an in vivo model. For these purposes, male Wistar rats (210-300 g) were injected with a single dose of pilocarpine hydrochloride (2.4 mg/2 µl) into the right lateral ventricle and video-monitored 24 h/day to detect spontaneous and recurrent seizures. Once detected, rats were implanted with microelectrodes in these regions (fixed-recording tungsten wire electrodes, 60-μm outer diameter) ipsilateral to the pilocarpine injection. A total of 336 fast ripples were recorded and probabilistically characterized, from those fast ripples we made a subset of all the fast ripple events associated with sharp-waves in CA1 region (n = 40) to analyze them with Granger Causality. RESULTS Our results support existing evidence in vitro in which fast ripple events in CA1 are initiated by CA3 multiunit activity and describe a general synchronization in the theta band across the three regions analyzed DG, CA3, and CA1, just before the fast ripple event in CA1 have begun. CONCLUSION This in vivo study highlights the causal participation of the CA3 back-projection to the DG, a connection commonly overlooked in the trisynaptic circuit, as a facilitator of a closed-loop among these regions that prolongs the excitatory activity of CA3. We speculate that the loss of inhibitory drive of DG and the mechanisms of ripple-related memory consolidation in which also the CA3 back-projection to DG has a fundamental role might be underlying processes of the fast ripples generation in CA1.
Collapse
Affiliation(s)
- Miguel A Núñez-Ochoa
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico
| | - Gustavo A Chiprés-Tinajero
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico
| | - Nadia P González-Domínguez
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
| | - Laura Medina-Ceja
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico.
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico.
| |
Collapse
|
27
|
Chiprés-Tinajero GA, Núñez-Ochoa MA, Medina-Ceja L. Increased immunoreactivity of glutamate receptors, neuronal nuclear protein and glial fibrillary acidic protein in the hippocampus of epileptic rats with fast ripple activity. Exp Brain Res 2021; 239:2015-2024. [PMID: 33909110 DOI: 10.1007/s00221-021-06108-6] [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: 10/07/2020] [Accepted: 04/08/2021] [Indexed: 11/28/2022]
Abstract
Epilepsy is a neurological disorder in which an imbalance between excitatory and inhibitory transmission is observed. Glutamate is the principal excitatory neurotransmitter that acts through ionic and metabotropic receptors; both types of receptors are involved in temporal lobe epilepsy (TLE). High frequency oscillations called fast ripples (FR, 250-600 Hz) have been observed, particularly in the hippocampus, and they are involved in epileptogenesis. The present study analyzed the immunoreactivity of the principal glutamate receptors associated with epilepsy in epileptic animals with FR activity. Male Swiss-Wistar rats (210-250 gr) were injected with pilocarpine (2.4 mg/2 µl) and were video monitored (24/7) until the appearance of spontaneous and recurrent seizures. Then, a deep microelectrode implantation surgery was performed in the DG, CA3 and CA1 regions, and FR activity was observed 1-, 2-, 3-, 7-, and 14-day postsurgery. The animals were sacrificed on day 15, and fluorescence immunohistochemistry was carried out in the hippocampus for the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA) and mGlu-R5 glutamate receptors as well as Neuronal Nuclear Protein (NeuN) and Glial Fibrillary Acidic Protein (GFAP). An increase in the immunoreactivity for the three receptors was found. However, the AMPA receptor showed an increase in the three regions analyzed (i.e., DG, CA1 and CA3). The findings showed a decrease of NeuN in the DG and an increase of GFAP. These results suggest an important role of glutamate receptors in the hippocampus of epileptic rats with FR activity.
Collapse
Affiliation(s)
- Gustavo A Chiprés-Tinajero
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, Zapopan, Jalisco, 45110, México
| | - Miguel A Núñez-Ochoa
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, Zapopan, Jalisco, 45110, México
| | - Laura Medina-Ceja
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, Zapopan, Jalisco, 45110, México.
| |
Collapse
|
28
|
Uva L, Aracri P, Forcaia G, de Curtis M. Mapping region-specific seizure-like patterns in the in vitro isolated guinea pig brain. Exp Neurol 2021; 342:113727. [PMID: 33930392 DOI: 10.1016/j.expneurol.2021.113727] [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: 02/12/2021] [Revised: 04/09/2021] [Accepted: 04/22/2021] [Indexed: 10/21/2022]
Abstract
Specific neurophysiological seizure patterns in patients with focal epilepsy depend on cerebral location and the underlying neuropathology. Location-specific patterns have been also reported in experimental models. Two focal seizure patterns, named p-type and l-type, typical of neocortical and mesial temporal regions were identified in both patients explored with intracerebral EEG and in animal models. These two patterns were recorded in the olfactory regions and in the entorhinal cortex after either 4AP or BMI administration. Here we mapped epileptiform activities in other cortices to verify the existence of specific epileptiform patterns. Field potentials were simultaneously recorded at multiple locations in olfactory, limbic and neocortical regions of the isolated guinea pig brain after arterial administration of either 4AP or BMI. Most neocortical areas did not generate new distinctive focal seizure-like event (SLE), beside the p-type and l-type patterns. Spiking activity was typically recorded after BMI in all new analyzed regions, whereas SLEs were commonly observed during 4AP perfusion. We confirmed the presence of reproducible region-specific epileptiform patterns in all explored cortical areas and demonstrated that strongly inter-connected areas generate similar SLEs. Our study suggests that p- and l-type SLE represent the most common focal seizure patterns during acute manipulations with pro-epileptic compounds.
Collapse
Affiliation(s)
- Laura Uva
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, via Amadeo 42, 20133 Milano, Italy.
| | - Patrizia Aracri
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, via Amadeo 42, 20133 Milano, Italy
| | - Greta Forcaia
- School of Medicine and Surgery, University of Milano-Bicocca, via Cadore 48, 20900 Monza, MB, Italy.
| | - Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, via Amadeo 42, 20133 Milano, Italy.
| |
Collapse
|
29
|
The Kainic Acid Models of Temporal Lobe Epilepsy. eNeuro 2021; 8:ENEURO.0337-20.2021. [PMID: 33658312 PMCID: PMC8174050 DOI: 10.1523/eneuro.0337-20.2021] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/14/2021] [Accepted: 01/24/2021] [Indexed: 12/14/2022] Open
Abstract
Experimental models of epilepsy are useful to identify potential mechanisms of epileptogenesis, seizure genesis, comorbidities, and treatment efficacy. The kainic acid (KA) model is one of the most commonly used. Several modes of administration of KA exist, each producing different effects in a strain-, species-, gender-, and age-dependent manner. In this review, we discuss the advantages and limitations of the various forms of KA administration (systemic, intrahippocampal, and intranasal), as well as the histologic, electrophysiological, and behavioral outcomes in different strains and species. We attempt a personal perspective and discuss areas where work is needed. The diversity of KA models and their outcomes offers researchers a rich palette of phenotypes, which may be relevant to specific traits found in patients with temporal lobe epilepsy.
Collapse
|
30
|
Li L, He L, Harris N, Zhou Y, Engel J, Bragin A. Topographical reorganization of brain functional connectivity during an early period of epileptogenesis. Epilepsia 2021; 62:1231-1243. [PMID: 33720411 DOI: 10.1111/epi.16863] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The current study aims to investigate functional brain network representations during the early period of epileptogenesis. METHODS Eighteen rats with the intrahippocampal kainate model of mesial temporal lobe epilepsy were used for this experiment. Functional magnetic resonance imaging (fMRI) measurements were made 1 week after status epilepticus, followed by 2-4-month electrophysiological and video monitoring. Animals were identified as having (1) developed epilepsy (E+, n = 9) or (2) not developed epilepsy (E-, n = 6). Nine additional animals served as controls. Graph theory analysis was performed on the fMRI data to quantify the functional brain networks in all animals prior to the development of epilepsy. Spectrum clustering with the network features was performed to estimate their predictability in epileptogenesis. RESULTS Our data indicated that E+ animals showed an overall increase in functional connectivity strength compared to E- and control animals. Global network features and small-worldness of E- rats were similar to controls, whereas E+ rats demonstrated increased small-worldness, including increased reorganization degree, clustering coefficient, and global efficiency, with reduced shortest pathlength. A notable classification of the combined brain network parameters was found in E+ and E- animals. For the local network parameters, the E- rats showed increased hubs in sensorimotor cortex, and decreased hubness in hippocampus. The E+ rats showed a complete loss of hippocampal hubs, and the appearance of new hubs in the prefrontal cortex. We also observed that lesion severity was not related to epileptogenesis. SIGNIFICANCE Our data provide a view of the reorganization of topographical functional brain networks in the early period of epileptogenesis and how it can significantly predict the development of epilepsy. The differences from E- animals offer a potential means for applying noninvasive neuroimaging tools for the early prediction of epilepsy.
Collapse
Affiliation(s)
- Lin Li
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA.,Department of Biomedical Engineering, University of North Texas, Denton, Texas, USA
| | - Lingna He
- Department of Computer Science, Zhejiang University of Technology, Zhejiang, China
| | - Neil Harris
- Department of Neurosurgery, UCLA Brain Injury Research Center, University of California, Los Angeles,, Los Angeles, California, USA.,Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA.,Semel Institute for Neuroscience and Human Behavior, Intellectual Development and Disorders Research Center, University of California, Los Angeles, Los Angeles, California, USA
| | - Yufeng Zhou
- Department of Biomedical Engineering, University of North Texas, Denton, Texas, USA
| | - Jerome Engel
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA.,Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA.,Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.,Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Anatol Bragin
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA.,Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA
| |
Collapse
|
31
|
Liu H, Tufa U, Zahra A, Chow J, Sivanenthiran N, Cheng C, Liu Y, Cheung P, Lim S, Jin Y, Mao M, Sun Y, Wu C, Wennberg R, Bardakjian B, Carlen PL, Eubanks JH, Song H, Zhang L. Electrographic Features of Spontaneous Recurrent Seizures in a Mouse Model of Extended Hippocampal Kindling. Cereb Cortex Commun 2021; 2:tgab004. [PMID: 34296153 PMCID: PMC8152854 DOI: 10.1093/texcom/tgab004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 01/08/2021] [Accepted: 01/13/2021] [Indexed: 01/14/2023] Open
Abstract
Epilepsy is a chronic neurological disorder characterized by spontaneous recurrent seizures (SRS) and comorbidities. Kindling through repetitive brief stimulation of a limbic structure is a commonly used model of temporal lobe epilepsy. Particularly, extended kindling over a period up to a few months can induce SRS, which may simulate slowly evolving epileptogenesis of temporal lobe epilepsy. Currently, electroencephalographic (EEG) features of SRS in rodent models of extended kindling remain to be detailed. We explored this using a mouse model of extended hippocampal kindling. Intracranial EEG recordings were made from the kindled hippocampus and unstimulated hippocampal, neocortical, piriform, entorhinal, or thalamic area in individual mice. Spontaneous EEG discharges with concurrent low-voltage fast onsets were observed from the two corresponding areas in nearly all SRS detected, irrespective of associated motor seizures. Examined in brain slices, epileptiform discharges were induced by alkaline artificial cerebrospinal fluid in the hippocampal CA3, piriform and entorhinal cortical areas of extended kindled mice but not control mice. Together, these in vivo and in vitro observations suggest that the epileptic activity involving a macroscopic network may generate concurrent discharges in forebrain areas and initiate SRS in hippocampally kindled mice.
Collapse
Affiliation(s)
- Haiyu Liu
- Departments of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021 China.,Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Uilki Tufa
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8.,Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 3H5, Canada
| | - Anya Zahra
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Jonathan Chow
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Nila Sivanenthiran
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Chloe Cheng
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Yapg Liu
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Phinehas Cheung
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Stellar Lim
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Yaozhong Jin
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Min Mao
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Yuqing Sun
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Chiping Wu
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Richard Wennberg
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8.,Department of Medicine, University of Toronto, Toronto, Ontario M2K 1E2, Canada
| | - Berj Bardakjian
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 3H5, Canada
| | - Peter L Carlen
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8.,Department of Medicine, University of Toronto, Toronto, Ontario M2K 1E2, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - James H Eubanks
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8.,Department of Surgery, University of Toronto, Toronto, Ontario M5G 1X5, Canada
| | - Hongmei Song
- Departments of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin 130021 China.,Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8
| | - Liang Zhang
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada M5T 2S8.,Department of Medicine, University of Toronto, Toronto, Ontario M2K 1E2, Canada
| |
Collapse
|
32
|
Jacobs J, Zijlmans M. HFO to Measure Seizure Propensity and Improve Prognostication in Patients With Epilepsy. Epilepsy Curr 2020; 20:338-347. [PMID: 33081501 PMCID: PMC7818207 DOI: 10.1177/1535759720957308] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The study of high frequency oscillations (HFO) in the electroencephalogram (EEG)
as biomarkers of epileptic activity has merely focused on their spatial location
and relationship to the epileptogenic zone. It has been suggested in several
ways that the amount of HFO at a certain point in time may reflect the disease
activity or severity. This could be clinically useful in several ways,
especially as noninvasive recording of HFO appears feasible. We grouped the
potential hypotheses into 4 categories: (1) HFO as biomarkers to predict the
development of epilepsy; (2) HFO as biomarkers to predict the occurrence of
seizures; (3) HFO as biomarkers linked to the severity of epilepsy, and (4) HFO
as biomarkers to evaluate outcome of treatment. We will review the literature
that addresses these 4 hypotheses and see to what extent HFO can be used to
measure seizure propensity and help determine prognosis of this unpredictable
disease.
Collapse
Affiliation(s)
- Julia Jacobs
- 157744Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Maeike Zijlmans
- 36512UMC Utrecht Brain Center Rudolf Magnus, Utrecht, the Netherlands
| |
Collapse
|
33
|
Scott JM, Ren S, Gliske SV, Stacey WC. Preictal variability of high-frequency oscillation rates in refractory epilepsy. Epilepsia 2020; 61:2521-2533. [PMID: 32944942 DOI: 10.1111/epi.16680] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE High-frequency oscillations (HFOs) have shown promising utility in the spatial localization of the seizure onset zone for patients with focal refractory epilepsy. Comparatively few studies have addressed potential temporal variations in HFOs, or their role in the preictal period. Here, we introduce a novel evaluation of the instantaneous HFO rate through interictal and peri-ictal epochs to assess their usefulness in identifying imminent seizure onset. METHODS Utilizing an automated HFO detector, we analyzed intracranial electroencephalographic data from 30 patients with refractory epilepsy undergoing long-term presurgical evaluation. We evaluated HFO rates both as a 30-minute average and as a continuous function of time and used nonparametric statistical methods to compare individual and population-level differences in rate during peri-ictal and interictal periods. RESULTS Mean HFO rate was significantly higher for all epochs in seizure onset zone channels versus other channels. Across the 30 patients of our cohort, we found no statistically significant differences in mean HFO rate during preictal and interictal epochs. For continuous HFO rates in seizure onset zone channels, however, we found significant population-wide increases in preictal trends relative to interictal periods. Using a data-driven analysis, we identified a subset of 11 patients in whom either preictal HFO rates or their continuous trends were significantly increased relative to those of interictal baseline and the rest of the population. SIGNIFICANCE These results corroborate existing findings that HFO rates within epileptic tissue are higher during interictal periods. We show this finding is also present in preictal, ictal, and postictal data, and identify a novel biomarker of preictal state: an upward trend in HFO rate leading into seizures in some patients. Overall, our findings provide preliminary evidence that HFOs can function as a temporal biomarker of seizure onset.
Collapse
Affiliation(s)
- Jared M Scott
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Sijin Ren
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, USA
| | - Stephen V Gliske
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.,Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
| | - William C Stacey
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, USA.,Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA.,Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
34
|
Fumeaux NF, Ebrahim S, Coughlin BF, Kadambi A, Azmi A, Xu JX, Jaoude MA, Nagaraj SB, Thomson KE, Newell TG, Metcalf CS, Wilcox KS, Kimchi EY, Moraes MFD, Cash SS. Accurate detection of spontaneous seizures using a generalized linear model with external validation. Epilepsia 2020; 61:1906-1918. [PMID: 32761902 PMCID: PMC7953845 DOI: 10.1111/epi.16628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Seizure detection is a major facet of electroencephalography (EEG) analysis in neurocritical care, epilepsy diagnosis and management, and the instantiation of novel therapies such as closed-loop stimulation or optogenetic control of seizures. It is also of increased importance in high-throughput, robust, and reproducible pre-clinical research. However, seizure detectors are not widely relied upon in either clinical or research settings due to limited validation. In this study, we create a high-performance seizure-detection approach, validated in multiple data sets, with the intention that such a system could be available to users for multiple purposes. METHODS We introduce a generalized linear model trained on 141 EEG signal features for classification of seizures in continuous EEG for two data sets. In the first (Focal Epilepsy) data set consisting of 16 rats with focal epilepsy, we collected 1012 spontaneous seizures over 3 months of 24/7 recording. We trained a generalized linear model on the 141 features representing 20 feature classes, including univariate and multivariate, linear and nonlinear, time, and frequency domains. We tested performance on multiple hold-out test data sets. We then used the trained model in a second (Multifocal Epilepsy) data set consisting of 96 rats with 2883 spontaneous multifocal seizures. RESULTS From the Focal Epilepsy data set, we built a pooled classifier with an Area Under the Receiver Operating Characteristic (AUROC) of 0.995 and leave-one-out classifiers with an AUROC of 0.962. We validated our method within the independently constructed Multifocal Epilepsy data set, resulting in a pooled AUROC of 0.963. We separately validated a model trained exclusively on the Focal Epilepsy data set and tested on the held-out Multifocal Epilepsy data set with an AUROC of 0.890. Latency to detection was under 5 seconds for over 80% of seizures and under 12 seconds for over 99% of seizures. SIGNIFICANCE This method achieves the highest performance published for seizure detection on multiple independent data sets. This method of seizure detection can be applied to automated EEG analysis pipelines as well as closed loop interventional approaches, and can be especially useful in the setting of research using animals in which there is an increased need for standardization and high-throughput analysis of large number of seizures.
Collapse
Affiliation(s)
- Nicolas F. Fumeaux
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Senan Ebrahim
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Brian F. Coughlin
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Adesh Kadambi
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Aafreen Azmi
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jen X. Xu
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Maurice Abou Jaoude
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sunil B. Nagaraj
- Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Kyle E. Thomson
- Department of Pharmacology, University of Utah, Salt Lake City, UT, USA
| | - Thomas G. Newell
- Department of Pharmacology, University of Utah, Salt Lake City, UT, USA
| | | | - Karen S. Wilcox
- Department of Pharmacology, University of Utah, Salt Lake City, UT, USA
| | - Eyal Y. Kimchi
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | | | - Sydney S. Cash
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
35
|
Salami P, Peled N, Nadalin JK, Martinet LE, Kramer MA, Lee JW, Cash SS. Seizure onset location shapes dynamics of initiation. Clin Neurophysiol 2020; 131:1782-1797. [PMID: 32512346 DOI: 10.1016/j.clinph.2020.04.168] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/24/2020] [Accepted: 04/13/2020] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Ictal electrographic patterns are widely thought to reflect underlying neural mechanisms of seizures. Here we studied the degree to which seizure patterns are consistent in a given patient, relate to particular brain regions and if two candidate biomarkers (high-frequency oscillations, HFOs; infraslow activity, ISA) and network activity, as assessed with cross-frequency interactions, can discriminate between seizure types. METHODS We analyzed temporal changes in low and high frequency oscillations recorded during seizures, as well as phase-amplitude coupling (PAC) to monitor the interactions between delta/theta and ripple/fast ripple frequency bands at seizure onset. RESULTS Seizures of multiple electrographic patterns were observed in a given patient and brain region. While there was an increase in HFO rate across different electrographic patterns, there are specific relationships between types of HFO activity and onset region. Similarly, changes in PAC dynamics were more closely related to seizure onset region than they were to electrographic patterns while ISA was a poor indicator for seizure onset. CONCLUSIONS Our findings suggest that the onset region sculpts neurodynamics at seizure initiation and that unique features of the cytoarchitecture and/or connectivity of that region play a significant role in determining seizure mechanism. SIGNIFICANCE To learn how seizures are initiated, researchers would do well to consider other aspects of their manifestation, in addition to their electrographic patterns. Examination of onset pattern in conjunction with the interactions between different oscillatory frequencies in the context of different brain regions might be more informative and lead to more reliable clinical inference as well as novel therapeutic approaches.
Collapse
Affiliation(s)
- Pariya Salami
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Noam Peled
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jessica K Nadalin
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Louis-Emmanuel Martinet
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Jong W Lee
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
36
|
Zhao J, Zheng Y, Liu K, Chen J, Lai N, Fei F, Shi J, Xu C, Wang S, Nishibori M, Wang Y, Chen Z. HMGB1 Is a Therapeutic Target and Biomarker in Diazepam-Refractory Status Epilepticus with Wide Time Window. Neurotherapeutics 2020; 17:710-721. [PMID: 31802434 PMCID: PMC7283397 DOI: 10.1007/s13311-019-00815-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Status epilepticus (SE), a life-threatening neurologic emergency, is often poorly controlled by the current pharmacological therapeutics, which are limited to a narrow time window. Here, we investigated the proinflammatory cytokine high mobility group box-1 (HMGB1) as a candidate therapeutic target for diazepam (DZP)-refractory SE. We found that HMGB1 was upregulated and translocated rapidly during refractory SE period. Exogenous HMGB1 was sufficient to directly induce DZP-refractory SE in nonrefractory SE. Neutralization of HMGB1 with an anti-HMGB1 monoclonal antibody decreased the incidence of SE and alleviated the severity of seizure activity in DZP-refractory SE, which was mediated by a Toll-like receptor 4 (TLR4)-dependent pathway. Importantly, anti-HMGB1 mAb reversed DZP-refractory SE with a wide time window, extending the therapeutic window from 30 to 180 min. Furthermore, we found the upregulation of plasma HMGB1 level is closely correlated with the therapeutic response of anti-HMGB1 mAb in DZP-refractory SE. All these results indicated that HMGB1 is a potential therapeutic target and a useful predictive biomarker in DZP-refractory SE.
Collapse
Affiliation(s)
- Junli Zhao
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yang Zheng
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Keyue Liu
- Department of Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Junzi Chen
- Hangzhou No. 4 High School, Hangzhou, China
| | - Nanxi Lai
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Fan Fei
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Jiaying Shi
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Cenglin Xu
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Shuang Wang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Masahiro Nishibori
- Department of Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Yi Wang
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| |
Collapse
|
37
|
A disinhibitory nigra-parafascicular pathway amplifies seizure in temporal lobe epilepsy. Nat Commun 2020; 11:923. [PMID: 32066723 PMCID: PMC7026152 DOI: 10.1038/s41467-020-14648-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 01/26/2020] [Indexed: 01/11/2023] Open
Abstract
The precise circuit of the substantia nigra pars reticulata (SNr) involved in temporal lobe epilepsy (TLE) is still unclear. Here we found that optogenetic or chemogenetic activation of SNr parvalbumin+ (PV) GABAergic neurons amplifies seizure activities in kindling- and kainic acid-induced TLE models, whereas selective inhibition of these neurons alleviates seizure activities. The severity of seizures is bidirectionally regulated by optogenetic manipulation of SNr PV fibers projecting to the parafascicular nucleus (PF). Electrophysiology combined with rabies virus-assisted circuit mapping shows that SNr PV neurons directly project to and functionally inhibit posterior PF GABAergic neurons. Activity of these neurons also regulates seizure activity. Collectively, our results reveal that a long-range SNr-PF disinhibitory circuit participates in regulating seizure in TLE and inactivation of this circuit can alleviate severity of epileptic seizures. These findings provide a better understanding of pathological changes from a circuit perspective and suggest a possibility to precisely control epilepsy. The neural circuits through which the substantia nigra pars reticulata (SNr) exerts its role in epilepsy control are not known. Here the authors reveal that a long-range SNr-parafascicular nucleus disinhibitory circuit participates in regulating seizures in temporal lobe epilepsy and inhibition of this circuit can alleviate severity of epileptic seizures.
Collapse
|
38
|
Klorig DC, Alberto GE, Smith T, Godwin DW. Optogenetically-Induced Population Discharge Threshold as a Sensitive Measure of Network Excitability. eNeuro 2019; 6:ENEURO.0229-18.2019. [PMID: 31619450 PMCID: PMC6838688 DOI: 10.1523/eneuro.0229-18.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 09/06/2019] [Accepted: 09/27/2019] [Indexed: 12/21/2022] Open
Abstract
Network excitability is governed by synaptic efficacy, intrinsic excitability, and the circuitry in which these factors are expressed. The complex interplay between these factors determines how circuits function and, at the extreme, their susceptibility to seizure. We have developed a sensitive, quantitative estimate of network excitability in freely behaving mice using a novel optogenetic intensity-response procedure. Synchronous activation of deep sublayer CA1 pyramidal cells produces abnormal network-wide epileptiform population discharges (PDs) that are nearly indistinguishable from spontaneously-occurring interictal spikes (IISs). By systematically varying light intensity, and therefore the magnitude of the optogenetically-mediated current, we generated intensity-response curves using the probability of PD as the dependent variable. Manipulations known to increase excitability, such as sub-convulsive doses (20 mg/kg) of the chemoconvulsant pentylenetetrazol (PTZ), produced a leftward shift in the curve compared to baseline. The anti-epileptic drug levetiracetam (LEV; 40 mk/kg), in combination with PTZ, produced a rightward shift. Optogenetically-induced PD threshold (oPDT) baselines were stable over time, suggesting the metric is appropriate for within-subject experimental designs with multiple pharmacological manipulations.
Collapse
Affiliation(s)
- D C Klorig
- Department of Neurobiology and Anatomy
- Neuroscience Program
| | - G E Alberto
- Department of Neurobiology and Anatomy
- Neuroscience Program
| | - T Smith
- Department of Neurobiology and Anatomy
| | - D W Godwin
- Department of Neurobiology and Anatomy
- Neuroscience Program
- Department of Physiology and Pharmacology, Wake Forest University, Winston-Salem, NC
| |
Collapse
|
39
|
Schönberger J, Frauscher B, von Ellenrieder N, Avoli M, Dubeau F, Gotman J. Fast ripple analysis in human mesial temporal lobe epilepsy suggests two different seizure-generating mechanisms. Neurobiol Dis 2019; 127:374-381. [DOI: 10.1016/j.nbd.2019.03.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/19/2019] [Accepted: 03/26/2019] [Indexed: 12/16/2022] Open
|
40
|
Neuroprotective effects of a protein tyrosine phosphatase inhibitor against hippocampal excitotoxic injury. Brain Res 2019; 1719:133-139. [PMID: 31128098 DOI: 10.1016/j.brainres.2019.05.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/07/2019] [Accepted: 05/21/2019] [Indexed: 11/23/2022]
Abstract
Neuronal excitotoxicity is the neuronal cell death arising from prolonged exposure to glutamate and the associated excessive influx of ions into the cell. Sodium orthovanadate (Na3VO4,) competitively inhibits the protein tyrosine phosphatases that affect intracellular protein phosphorylation. No study has examined the role of protein tyrosine phosphatases in kainic acid (KA)-induced excitotoxic injury using sodium orthovanadate. Thus, the present study was conducted to determine the neuroprotective effects of sodium orthovanadate on KA-induced neuronal death in organotypic hippocampal slice culture. We also performed an in vivo electrophysiology study in Sprague-Dawley rats to observe the function of surviving cells after sodium orthovanadate treatment in KA-induced excitotoxicity. Rats were anaesthetized with sodium pentobarbital and KA was injected unilaterally in CA3 of the hippocampus by microinjection-cannula. Neuronal cell death, as assessed by propidium iodide uptake, was reduced by 10 and 25 μM sodium orthovanadate treatment (24 and 48 h) compared with the KA-only group. Sodium orthovanadate enhanced survival signals by increasing levels of phospho-Akt and superoxide dismutase. In addition, sodium orthovanadate treatment reduced calcineurin level for neuronal protection, which regulates activation of cellular calcium caused by KA-induced injury. In vivo results showed that sodium orthovanadate treatment elicited resistance to KA-induced behavior seizures and significantly reduced the duration of epileptiform discharges. In addition, sodium orthovanadate treatment (25 mM) significantly prevented the increase in power spectra induced by KA injection. These results suggest that sodium orthovanadate decreases the acute effects of KA, thereby inducing neuroprotective effects with reduced reactive oxygen species and cellular Ca2+. Thus, sodium orthovanadate may protect hippocampal neurons against excitotoxicity, and surviving neurons may function to reduce seizures.
Collapse
|
41
|
Li L, Bragin A, Staba R, Engel J. Unit firing and oscillations at seizure onset in epileptic rodents. Neurobiol Dis 2019; 127:382-389. [PMID: 30928646 DOI: 10.1016/j.nbd.2019.03.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/04/2019] [Accepted: 03/26/2019] [Indexed: 01/27/2023] Open
Abstract
Epileptic seizures result from a variety of pathophysiological processes, evidenced by different electrographic ictal onset patterns, as seen on direct brain recordings. The two most common electrographic patterns of focal ictal onset in patients are hypersynchronous (HYP) and low-voltage fast (LVF). Whereas LVF ictal onsets were believed to result from disinhibition; based on similarities with absence seizures, focal HYP ictal onsets were believed to result from increased synchronizing inhibition. Recent findings, however, suggest the differences between these seizure onset types are more complicated and, in some cases, the opposite of these concepts are true. The following review presents evidence that a reduction of tonic inhibition on small pathologically interconnected neuron (PIN) clusters generating pathological high-frequency oscillations (pHFOs), which reflect abnormal synchronously bursting neurons may be the cause of HYP ictal onsets. Increased inhibition preceding LVF ictal onsets are discussed in other reviews in this issue. We postulate that neuronal cell loss following epileptogenic insults can result in structural reorganization, giving rise to small PIN clusters, which generate pHFOs. These clusters have a heterogeneous distribution and are spatially stable over time. Studies have demonstrated that a transient reduction in tonic inhibition causes these clusters to increase in size. This could result in consolidation and synchronization of pHFOs until a critical mass leads to propagation of HYP ictal discharges. Viewed within a network neuroscience framework, local disturbances such as PIN clusters are likely to contribute to large-scale brain network alterations: a better understanding of these epileptogenic networks promises to elucidate mechanisms of ictogenesis, epileptogenesis, and certain comorbidities of epilepsy.
Collapse
Affiliation(s)
- Lin Li
- Department of Neurology, University of California, Los Angeles, CA, USA
| | - Anatol Bragin
- Department of Neurology, University of California, Los Angeles, CA, USA; Brain Research Institute, University of California, Los Angeles, CA, USA
| | - Richard Staba
- Department of Neurology, University of California, Los Angeles, CA, USA
| | - Jerome Engel
- Department of Neurology, University of California, Los Angeles, CA, USA; Brain Research Institute, University of California, Los Angeles, CA, USA; Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
| |
Collapse
|
42
|
Moxon KA, Shahlaie K, Girgis F, Saez I, Kennedy J, Gurkoff GG. From adagio to allegretto: The changing tempo of theta frequencies in epilepsy and its relation to interneuron function. Neurobiol Dis 2019; 129:169-181. [PMID: 30798003 DOI: 10.1016/j.nbd.2019.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/06/2019] [Accepted: 02/20/2019] [Indexed: 12/29/2022] Open
Abstract
Despite decades of research, our understanding of epilepsy, including how seizures are generated and propagate, is incomplete. However, there is growing recognition that epilepsy is more than just the occurrence of seizures, with patients often experiencing comorbid deficits in cognition that are poorly understood. In addition, the available therapies for treatment of epilepsy, from pharmaceutical treatment to surgical resection and seizure prevention devices, often exacerbate deficits in cognitive function. In this review, we discuss the hypothesis that seizure generation and cognitive deficits have a similar pathological source characterized by, but not limited to, deficits in theta oscillations and their influence on interneurons. We present a new framework that describes oscillatory states in epilepsy as alternating between hyper- and hypo-synchrony rather than solely the spontaneous transition to hyper-excitability characterized by the seizures. This framework suggests that as neural oscillations, specifically in the theta range, vary their tempo from a slowed almost adagio tempo during interictal periods to faster, more rhythmic allegretto tempo preictally, they impact the function of interneurons, modulating their ability to control seizures and their role in cognitive processing. This slow wave oscillatory framework may help explain why current therapies that work to reduce hyper-excitability do not completely eliminate seizures and often lead to exacerbated cognitive deficits.
Collapse
Affiliation(s)
- Karen A Moxon
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, United States of America.
| | - Kiarash Shahlaie
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
| | - Fady Girgis
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America
| | - Ignacio Saez
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
| | - Jeffrey Kennedy
- Department of Neurology, University of California Davis, Sacramento, CA 95817, United States of America
| | - Gene G Gurkoff
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
| |
Collapse
|
43
|
Lévesque M, Avoli M. High-frequency oscillations and focal seizures in epileptic rodents. Neurobiol Dis 2018; 124:396-407. [PMID: 30590178 DOI: 10.1016/j.nbd.2018.12.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/26/2018] [Accepted: 12/22/2018] [Indexed: 01/09/2023] Open
Abstract
High-pass filtering (> 80 Hz) of EEG signals has enabled neuroscientists to analyze high-frequency oscillations (HFOs; i.e., ripples: 80-200 Hz and fast ripples: 250-500 Hz) in epileptic patients presenting with focal seizures and in animal models mimicking this condition. Evidence obtained from these studies indicate that HFOs mirror pathological network activity that may initiate and sustain ictogenesis and epileptogenesis. HFOs are observed in temporal lobe regions of epileptic animals during interictal periods but they also occur before seizure onset and during the ictal period, suggesting that they can pinpoint to the mechanisms of seizure generation. Accordingly, ripples and fast ripples predominate during two specific seizure onset patterns termed low-voltage fast and hypersynchronous, respectively. In this review we will: (i) summarize these experimental studies; (ii) consider the evolution of HFOs over time during epileptogenesis; (iii) address data obtained with optogenetic stimulating procedures both in vitro and in vivo, and (iv) take into account the impact of anti-epileptic drugs on HFOs. We expect these findings to contribute to understanding the neuronal mechanisms leading to ictogenesis and epileptogenesis thus leading to the development of mechanistically targeted anti-epileptic strategies.
Collapse
Affiliation(s)
| | - Massimo Avoli
- Montreal Neurological Institute, Canada; Departments of Neurology & Neurosurgery, and of Physiology, McGill University, Montréal, H3A 2B4 Québec, Canada; Department of Experimental Medicine, Facoltà di Medicina e Odontoiatria, Sapienza University of Rome, 00185 Roma, Italy
| |
Collapse
|
44
|
Weiss SA, Staba R, Bragin A, Moxon K, Sperling M, Avoli M, Engel J. "Interneurons and principal cell firing in human limbic areas at focal seizure onset". Neurobiol Dis 2018; 124:183-188. [PMID: 30471414 DOI: 10.1016/j.nbd.2018.11.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/11/2018] [Accepted: 11/19/2018] [Indexed: 10/27/2022] Open
Affiliation(s)
- Shennan A Weiss
- Depts. of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - Richard Staba
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Anatol Bragin
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Karen Moxon
- Dept. of Biomedical Engineering, UC Davis, Davis, CA 95616, USA
| | - Michael Sperling
- Depts. of Neurology and Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Massimo Avoli
- Montreal Neurological Institute, Depts. of Neurology & Neurosurgery and of Physiology, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Jerome Engel
- Dept. of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Dept. of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Dept. of Neurobiology, Dept. of Psychiatry and Biobehavioral Sciences, Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| |
Collapse
|
45
|
Elahian B, Lado NE, Mankin E, Vangala S, Misra A, Moxon K, Fried I, Sharan A, Yeasin M, Staba R, Bragin A, Avoli M, Sperling MR, Engel J, Weiss SA. Low-voltage fast seizures in humans begin with increased interneuron firing. Ann Neurol 2018; 84:588-600. [PMID: 30179277 DOI: 10.1002/ana.25325] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 08/29/2018] [Accepted: 08/29/2018] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Intracellular recordings from cells in entorhinal cortex tissue slices show that low-voltage fast (LVF) onset seizures are generated by inhibitory events. Here, we determined whether increased firing of interneurons occurs at the onset of spontaneous mesial-temporal LVF seizures recorded in patients. METHODS The seizure onset zone (SOZ) was identified using visual inspection of the intracranial electroencephalogram. We used wavelet clustering and temporal autocorrelations to characterize changes in single-unit activity during the onset of LVF seizures recorded from microelectrodes in mesial-temporal structures. Action potentials generated by principal neurons and interneurons (ie, putative excitatory and inhibitory neurons) were distinguished using waveform morphology and K-means clustering. RESULTS From a total of 200 implanted microelectrodes in 9 patients during 13 seizures, we isolated 202 single units; 140 (69.3%) of these units were located in the SOZ, and 40 (28.57%) of them were classified as inhibitory. The waveforms of both excitatory and inhibitory units remained stable during the LVF epoch (p > > 0.05). In the mesial-temporal SOZ, inhibitory interneurons increased their firing rate during LVF seizure onset (p < 0.01). Excitatory neuron firing rates peaked 10 seconds after the inhibitory neurons (p < 0.01). During LVF spread to the contralateral mesial temporal lobe, an increase in inhibitory neuron firing rate was also observed (p < 0.01). INTERPRETATION Our results suggest that seizure generation and spread during spontaneous mesial-temporal LVF onset events in humans may result from increased inhibitory neuron firing that spawns a subsequent increase in excitatory neuron firing and seizure evolution. Ann Neurol 2018;84:588-600.
Collapse
Affiliation(s)
- Bahareh Elahian
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA.,Department of Neurology, Thomas Jefferson University, Philadelphia, PA.,Department of Electrical and Computer Engineering, University of Memphis, Memphis, TN
| | - Nathan E Lado
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA.,Department of Neurology, Thomas Jefferson University, Philadelphia, PA
| | - Emily Mankin
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Sitaram Vangala
- Department of Medicine, Statistics Core, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Amrit Misra
- Department of Neurology, Massachusetts General Hospital, Boston, MA
| | - Karen Moxon
- Department of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA
| | - Itzhak Fried
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Ashwini Sharan
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA
| | - Mohammed Yeasin
- Department of Electrical and Computer Engineering, University of Memphis, Memphis, TN
| | - Richard Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Anatol Bragin
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Massimo Avoli
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada.,Department of Physiology, McGill University, Montreal, Quebec, Canada.,Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | | | - Jerome Engel
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA.,Department of Psychiatry and Biobehavioral Sciences, Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Shennan A Weiss
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA.,Department of Neurology, Thomas Jefferson University, Philadelphia, PA
| |
Collapse
|
46
|
Engel J, Bragin A, Staba R. Nonictal EEG biomarkers for diagnosis and treatment. Epilepsia Open 2018; 3:120-126. [PMID: 30564770 PMCID: PMC6293068 DOI: 10.1002/epi4.12233] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2018] [Indexed: 12/11/2022] Open
Abstract
There are no reliable nonictal biomarkers for epilepsy, electroencephalography (EEG) or otherwise, but efforts to identify biomarkers that would predict the development of epilepsy after a potential epileptogenic insult, diagnose the existence of epilepsy, or assess the effects of antiseizure or antiepileptogenic interventions are relying heavily on electrophysiology. The most promising EEG biomarkers to date are pathologic high‐frequency oscillations (pHFOs), brief EEG events in the range of 100 to 600 Hz, which are believed to reflect summated action potentials from synchronously bursting neurons. Studies of patients with epilepsy, and experimental animal models, have been based primarily on direct brain recording, which makes pHFOs potentially useful for localizing the epileptogenic zone for surgical resection, but application for other diagnostic and therapeutic purposes is limited. Consequently, recent efforts have involved identification of HFOs recorded with scalp electrodes, and with magnetoencephalography, which may reflect the same pathophysiologic mechanisms as pHFOs recorded directly from the brain. The search is also on for other EEG changes that might serve as epilepsy biomarkers, and candidates include arcuate rhythms, which may reflect repetitive pHFOs, reduction in theta rhythm, which correlates with epileptogenesis in several rodent models of epilepsy, and shortened sleep spindles that correlate with ictogenesis.
Collapse
Affiliation(s)
- Jerome Engel
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaU.S.A.
- Brain Research InstituteUniversity of California Los AngelesLos AngelesCaliforniaU.S.A.
- Neurobiology and Psychiatry and Biobehavioral SciencesDavid Geffen School of Medicine at UCLALos AngelesCaliforniaU.S.A.
| | - Anatol Bragin
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaU.S.A.
- Brain Research InstituteUniversity of California Los AngelesLos AngelesCaliforniaU.S.A.
| | - Richard Staba
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaU.S.A.
| |
Collapse
|
47
|
Targeting the Mouse Ventral Hippocampus in the Intrahippocampal Kainic Acid Model of Temporal Lobe Epilepsy. eNeuro 2018; 5:eN-NWR-0158-18. [PMID: 30131968 PMCID: PMC6102375 DOI: 10.1523/eneuro.0158-18.2018] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/08/2018] [Accepted: 06/29/2018] [Indexed: 11/21/2022] Open
Abstract
Here we describe a novel mouse model of temporal lobe epilepsy (TLE) that moves the site of kainate injection from the rodent dorsal hippocampus (corresponding to the human posterior hippocampus) to the ventral hippocampus (corresponding to the human anterior hippocampus). We compare the phenotypes of this new model—with respect to seizures, cognitive impairment, affective deficits, and histopathology—to the standard dorsal intrahippocampal kainate model. Our results demonstrate that histopathological measures of granule cell dispersion and mossy fiber sprouting maximize near the site of kainate injection. Somewhat surprisingly, both the dorsal and ventral models exhibit similar spatial memory impairments in addition to similar electrographic and behavioral seizure burdens. In contrast, we find a more pronounced affective (anhedonic) phenotype specifically in the ventral model. These results demonstrate that the ventral intrahippocampal kainic acid model recapitulates critical pathologies of the dorsal model while providing a means to further study affective phenotypes such as depression in TLE.
Collapse
|
48
|
Abstract
Pentylenetetrazole (PTZ) is a GABA-A receptor antagonist. An intraperitoneal injection of PTZ into an animal induces an acute, severe seizure at a high dose, whereas sequential injections of a subconvulsive dose have been used for the development of chemical kindling, an epilepsy model. A single low-dose injection of PTZ induces a mild seizure without convulsion. However, repetitive low-dose injections of PTZ decrease the threshold to evoke a convulsive seizure. Finally, continuous low-dose administration of PTZ induces a severe tonic-clonic seizure. This method is simple and widely applicable to investigate the pathophysiology of epilepsy, which is defined as a chronic disease that involves repetitive seizures. This chemical kindling protocol causes repetitive seizures in animals. With this method, vulnerability to PTZ-mediated seizures or the degree of aggravation of epileptic seizures was estimated. These advantages have led to the use of this method for screening anti-epileptic drugs and epilepsy-related genes. In addition, this method has been used to investigate neuronal damage after epileptic seizures because the histological changes observed in the brains of epileptic patients also appear in the brains of chemical-kindled animals. Thus, this protocol is useful for conveniently producing animal models of epilepsy.
Collapse
Affiliation(s)
- Tadayuki Shimada
- Synaptic Plasticity Project, Tokyo Metropolitan Institute of Medical Science;
| | - Kanato Yamagata
- Synaptic Plasticity Project, Tokyo Metropolitan Institute of Medical Science;
| |
Collapse
|
49
|
Abstract
Epilepsy affects all age groups and is one of the most common and most disabling neurological disorders. The accurate diagnosis of seizures is essential as some patients will be misdiagnosed with epilepsy, whereas others will receive an incorrect diagnosis. Indeed, errors in diagnosis are common, and many patients fail to receive the correct treatment, which often has severe consequences. Although many patients have seizure control using a single medication, others require multiple medications, resective surgery, neuromodulation devices or dietary therapies. In addition, one-third of patients will continue to have uncontrolled seizures. Epilepsy can substantially impair quality of life owing to seizures, comorbid mood and psychiatric disorders, cognitive deficits and adverse effects of medications. In addition, seizures can be fatal owing to direct effects on autonomic and arousal functions or owing to indirect effects such as drowning and other accidents. Deciphering the pathophysiology of epilepsy has advanced the understanding of the cellular and molecular events initiated by pathogenetic insults that transform normal circuits into epileptic circuits (epileptogenesis) and the mechanisms that generate seizures (ictogenesis). The discovery of >500 genes associated with epilepsy has led to new animal models, more precise diagnoses and, in some cases, targeted therapies.
Collapse
Affiliation(s)
- Orrin Devinsky
- Departments of Neurology, Neuroscience, Neurosurgery and Psychiatry, NYU School of Medicine, New York, NY, USA
| | - Annamaria Vezzani
- Laboratory of Experimental Neurology, Department of Neuroscience, IRCCS 'Mario Negri' Institute for Pharmacological Research, Milan, Italy
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria, Australia.,Departments of Neurology and Medicine, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Nathalie Jette
- Department of Neurology and Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Victoria, Australia.,The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, and Department of Neurology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria, Australia.,Departments of Neurology and Medicine, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
50
|
Li L, Patel M, Almajano J, Engel J, Bragin A. Extrahippocampal high-frequency oscillations during epileptogenesis. Epilepsia 2018; 59:e51-e55. [PMID: 29508901 DOI: 10.1111/epi.14041] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2018] [Indexed: 01/23/2023]
Abstract
The current study aimed to investigate the spatial and temporal patterns of high-frequency oscillations (HFOs) in the intra-/extrahippocampal areas during epileptogenesis. Local field potentials were bilaterally recorded from hippocampus (CA1), thalamus, motor cortex, and prefrontal cortex in 13 rats before and after intrahippocampal kainic acid (KA) lesions. HFOs in the ripple (100-200 Hz) and fast ripple (250-500 Hz) ranges were detected and their rates were computed during different time periods (1-5 weeks) after KA-induced status epilepticus (SE). Recurrent spontaneous seizures were observed in 7 rats after SE, and the other 6 rats did not develop epilepsy. During the latent period, the rate of hippocampal HFOs increased at the ipsilateral site of the KA lesion in both groups, and the HFO rate was significantly higher in the animals that later developed epilepsy. Animals that later developed epilepsy also demonstrated widespread appearance of HFOs, in both the ripple and the fast ripple range, whereas animals that did not develop epilepsy only exhibited changes in the ipsilateral intrahippocampal HFO rate. This study demonstrates an association between an increased rate of widespread HFOs and the later development of epilepsy, suggesting the formation of large-scale distributed pathological networks during epileptogenesis.
Collapse
Affiliation(s)
- Lin Li
- Department of Neurology, University of California, Los Angeles, CA, USA
| | - Mayur Patel
- Department of Neurology, University of California, Los Angeles, CA, USA
| | - Joyel Almajano
- Department of Neurology, University of California, Los Angeles, CA, USA
| | - Jerome Engel
- Department of Neurology, University of California, Los Angeles, CA, USA.,Brain Research Institute, University of California, Los Angeles, CA, USA.,Departments of Neurobiology and Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Anatol Bragin
- Department of Neurology, University of California, Los Angeles, CA, USA.,Brain Research Institute, University of California, Los Angeles, CA, USA
| |
Collapse
|