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Tang Y, Zhu H, Xiao L, Li R, Han H, Tang W, Liu D, Zhou C, Liu D, Yang Z, Zhou L, Xiao B, Rominger A, Shi K, Hu S, Feng L. Individual cerebellar metabolic connectome in patients with MTLE and NTLE associated with surgical prognosis. Eur J Nucl Med Mol Imaging 2024:10.1007/s00259-024-06762-2. [PMID: 38805089 DOI: 10.1007/s00259-024-06762-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 05/12/2024] [Indexed: 05/29/2024]
Abstract
PURPOSE This study aimed to comprehensively explore the different metabolic connectivity topological changes in MTLE and NTLE, as well as their association with surgical outcomes. METHODS This study enrolled a cohort of patients with intractable MTLE and NTLE. Each individual's metabolic connectome, as determined by Kullback-Leibler divergence similarity estimation for the [18F]FDG PET image, was employed to conduct a comprehensive analysis of the cerebral metabolic network. Alterations in network connectivity were assessed by extracting and evaluating the strength of edge and weighted connectivity. By utilizing these two connectivity strength metrics with the cerebellum, we explored the network properties of connectivity and its association with prognosis in surgical patients. RESULTS Both MTLE and NTLE patients exhibited substantial alterations in the connectivity of the metabolic network at the edge and nodal levels (p < 0.01, FDR corrected). The key disparity between MTLE and NTLE was observed in the cerebellum. In MTLE, there was a predominance of increased connectivity strength in the cerebellum. Whereas, a decrease in cerebellar connectivity was identified in NTLE. It was found that in MTLE, higher edge connectivity and weighted connectivity strength in the contralateral cerebellar hemisphere correlated with improved surgical outcomes. Conversely, in NTLE, a higher edge metabolic connectivity strength in the ipsilateral cerebellar hemisphere suggested a worse surgical prognosis. CONCLUSION The cerebellum exhibits distinct topological characteristics in the metabolic networks between MTLE and NTLE. The hyper- or hypo-metabolic connectivity in the cerebellum may be a prognostic biomarker of surgical prognosis, which might aid in therapeutic decision-making for TLE individuals.
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Affiliation(s)
- Yongxiang Tang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
- Department of Nuclear Medicine, Inselspital, University Hospital Bern, Bern, Switzerland
| | - Haoyue Zhu
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, 410008, PR China
| | - Ling Xiao
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Rong Li
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu, China
| | - Honghao Han
- The Clinical Hospital of Chengdu Brain Science Institute, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu, China
| | - Weiting Tang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, 410008, PR China
| | - Ding Liu
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Chunyao Zhou
- Department of Neurosurgery, Xiangya Hospital, Central Southern University, Changsha, China
| | - Dingyang Liu
- Department of Neurosurgery, Xiangya Hospital, Central Southern University, Changsha, China
| | - Zhiquan Yang
- Department of Neurosurgery, Xiangya Hospital, Central Southern University, Changsha, China
| | - Luo Zhou
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, 410008, PR China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, 410008, PR China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Axel Rominger
- Department of Nuclear Medicine, Inselspital, University Hospital Bern, Bern, Switzerland
| | - Kuangyu Shi
- Department of Nuclear Medicine, Inselspital, University Hospital Bern, Bern, Switzerland
- Department of Informatics, Technische Universität München, Munich, Germany
| | - Shuo Hu
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
- Key Laboratory of Biological Nanotechnology of National Health Commission, Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | - Li Feng
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Rd, Changsha, 410008, PR China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
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Streng ML, Kottke BW, Wasserman EM, Zecker L, Luong L, Ebner TJ, Krook-Magnuson E. Early and widespread engagement of the cerebellum during hippocampal epileptiform activity Format: Brief Communication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.14.593969. [PMID: 38798649 PMCID: PMC11118491 DOI: 10.1101/2024.05.14.593969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Despite research illustrating the cerebellum may be a critical circuit element in the epilepsies, remarkably little is known about cerebellar engagement during seizures. We therefore implemented a novel method for repeated imaging of the cerebellum in awake, chronically epileptic animals. We found widespread changes in cerebellar calcium signals during behavioral seizures and during hippocampal seizures that remained electrographic only, arguing against cerebellar modulation simply reflecting motor components. Moreover, even brief interictal spikes produced widespread alterations in cerebellar activity. Changes were noted in the anterior and posterior cerebellum, along the midline, and both ipsilaterally and contralaterally to the seizure focus. Remarkably, changes in the cerebellum also occurred prior to any noticeable change in the hippocampal electrographic recordings, suggesting a special relationship between the cerebellum and hippocampal epileptiform activity. Together these results underscore the importance of the cerebellum in epilepsy, warranting a more consistent consideration of the cerebellum when evaluating epilepsy patients.
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Froula JM, Rose JJ, Krook-Magnuson C, Krook-Magnuson E. Distinct functional classes of CA1 hippocampal interneurons are modulated by cerebellar stimulation in a coordinated manner. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.14.594213. [PMID: 38798335 PMCID: PMC11118308 DOI: 10.1101/2024.05.14.594213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
There is mounting evidence that the cerebellum impacts hippocampal functioning, but the impact of the cerebellum on hippocampal interneurons remains obscure. Using miniscopes in freely behaving animals, we find optogenetic stimulation of Purkinje cells alters the calcium activity of a large percentage of CA1 interneurons. This includes both increases and decreases in activity. Remarkably, this bidirectional impact occurs in a coordinated fashion, in line with interneurons' functional properties. Specifically, CA1 interneurons activated by cerebellar stimulation are commonly locomotion-active, while those inhibited by cerebellar stimulation are commonly rest-active interneurons. We additionally find that subsets of CA1 interneurons show altered activity during object investigations, suggesting a role in the processing of objects in space. Importantly, these neurons also show coordinated modulation by cerebellar stimulation: CA1 interneurons that are activated by cerebellar stimulation are more likely to be activated, rather than inhibited, during object investigations, while interneurons that show decreased activity during cerebellar stimulation show the opposite profile. Therefore, CA1 interneurons play a role in object processing and in cerebellar impacts on the hippocampus, providing insight into previously noted altered CA1 processing of objects in space with cerebellar stimulation. We examined two different stimulation locations (IV/V Vermis; Simplex) and two different stimulation approaches (7Hz or a single 1s light pulse) - in all cases, the cerebellum induces similar coordinated CA1 interneuron changes congruent with an explorative state. Overall, our data show that the cerebellum impacts CA1 interneurons in a bidirectional and coordinated fashion, positioning them to play an important role in cerebello-hippocampal communication. Significance Statement Acute manipulation of the cerebellum can affect the activity of cells in CA1, and perturbing normal cerebellar functioning can affect hippocampal-dependent spatial processing, including the processing of objects in space. Despite the importance of interneurons on the local hippocampal circuit, it was unknown how cerebellar activation impacts CA1 inhibitory neurons. We find that stimulating the cerebellum robustly affects multiple populations of CA1 interneurons in a bidirectional, coordinated manner, according to their functional profiles during behavior, including locomotion and object investigations. Our work also provides support for a role of CA1 interneurons in spatial processing of objects, with populations of interneurons showing altered activity during object investigations.
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Huang YT, Chen YW, Lin TY, Chen JC. Suppression of presynaptic corticostriatal glutamate activity attenuates L-dopa-induced dyskinesia in 6-OHDA-lesioned Parkinson's disease mice. Neurobiol Dis 2024; 193:106452. [PMID: 38401650 DOI: 10.1016/j.nbd.2024.106452] [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: 09/18/2023] [Revised: 02/21/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024] Open
Abstract
A common adverse effect of Parkinson's disease (PD) treatment is L-dopa-induced dyskinesia (LID). This condition results from both dopamine (DA)-dependent and DA-independent mechanisms, as glutamate inputs from corticostriatal projection neurons impact DA-responsive medium spiny neurons in the striatum to cause the dyskinetic behaviors. In this study, we explored whether suppression of presynaptic corticostriatal glutamate inputs might affect the behavioral and biochemical outcomes associated with LID. We first established an animal model in which 6-hydroxydopamine (6-OHDA)-lesioned mice were treated daily with L-dopa (10 mg/kg, i.p.) for 2 weeks; these mice developed stereotypical abnormal involuntary movements (AIMs). When the mice were pretreated with the NMDA antagonist, amantadine, we observed suppression of AIMs and reductions of phosphorylated ERK1/2 and NR2B in the striatum. We then took an optogenetic approach to manipulate glutamatergic activity. Slc17a6 (vGluT2)-Cre mice were injected with pAAV5-Ef1a-DIO-eNpHR3.0-mCherry and received optic fiber implants in either the M1 motor cortex or dorsolateral striatum. Optogenetic inactivation at either optic fiber implant location could successfully reduce the intensity of AIMs after 6-OHDA lesioning and L-dopa treatment. Both optical manipulation strategies also suppressed phospho-ERK1/2 and phospho-NR2B signals in the striatum. Finally, we performed intrastriatal injections of LDN 212320 in the dyskenesic mice to enhance expression of glutamate uptake transporter GLT-1. Sixteen hours after the LDN 212320 treatment, L-dopa-induced AIMs were reduced along with the levels of striatal phospho-ERK1/2 and phospho-NR2B. Together, our results affirm a critical role of corticostriatal glutamate neurons in LID and strongly suggest that diminishing synaptic glutamate, either by suppression of neuronal activity or by upregulation of GLT-1, could be an effective approach for managing LID.
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Affiliation(s)
- Yu-Ting Huang
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Ya-Wen Chen
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Tze-Yen Lin
- Department and Graduate Institute of Physiology, National Taiwan University, College of Medicine, Taipei, Taiwan
| | - Jin-Chung Chen
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang-Gung University, Taoyuan, Taiwan; Department of Physiology and Pharmacology, Healthy Ageing Research Center, Chang-Gung University, Taiwan; Neuroscience Research Center and Department of Psychiatry, Chang-Gung Memorial Hospitall, Linkou, Taiwan.
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Streng ML. The bidirectional relationship between the cerebellum and seizure networks: a double-edged sword. Curr Opin Behav Sci 2023; 54:101327. [PMID: 38800711 PMCID: PMC11126210 DOI: 10.1016/j.cobeha.2023.101327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Epilepsy is highly prevalent and notoriously pharmacoresistant. New therapeutic interventions are urgently needed, both for preventing the seizures themselves as well as negative outcomes and comorbidities associated with chronic epilepsy. While the cerebellum is not traditionally associated with epilepsy or seizures, research over the past decade has outlined the cerebellum as a brain region that is uniquely suited for both therapeutic needs. This review discusses our current understanding of the cerebellum as a key node within seizure networks, capable of both attenuating seizures in several animal models, and conversely, prone to altered structure and function in chronic epilepsy. Critical next steps are to advance therapeutic modulation of the cerebellum more towards translation, and to provide a more comprehensive characterization of how the cerebellum is impacted by chronic epilepsy, in order to subvert negative outcomes.
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Affiliation(s)
- M L Streng
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
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Keever KM, Li Y, Womble PD, Sullens DG, Otazu GH, Lugo JN, Ramos RL. Neocortical and cerebellar malformations affect flurothyl-induced seizures in female C57BL/6J mice. Front Neurosci 2023; 17:1271744. [PMID: 38027492 PMCID: PMC10651747 DOI: 10.3389/fnins.2023.1271744] [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: 08/03/2023] [Accepted: 10/03/2023] [Indexed: 12/01/2023] Open
Abstract
Brain malformations cause cognitive disability and seizures in both human and animal models. Highly laminated structures such as the neocortex and cerebellum are vulnerable to malformation, affecting lamination and neuronal connectivity as well as causing heterotopia. The objective of the present study was to determine if sporadic neocortical and/or cerebellar malformations in C57BL/6J mice are correlated with reduced seizure threshold. The inhaled chemi-convulsant flurothyl was used to induce generalized, tonic-clonic seizures in male and female C57BL/6J mice, and the time to seizure onset was recorded as a functional correlate of brain excitability changes. Following seizures, mice were euthanized, and brains were extracted for histology. Cryosections of the neocortex and cerebellar vermis were stained and examined for the presence of molecular layer heterotopia as previously described in C57BL/6J mice. Over 60% of mice had neocortical and/or cerebellar heterotopia. No sex differences were observed in the prevalence of malformations. Significantly reduced seizure onset time was observed dependent on sex and the type of malformation present. These results raise important questions regarding the presence of malformations in C57BL/6J mice used in the study of brain development, epilepsy, and many other diseases of the nervous system.
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Affiliation(s)
- Katherine M. Keever
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, United States
| | - Ying Li
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, United States
| | - Paige D. Womble
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | - D. Gregory Sullens
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | - Gonzalo H. Otazu
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, United States
| | - Joaquin N. Lugo
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | - Raddy L. Ramos
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY, United States
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Feng X, Wang Q, Jin H, Yang S, Xing W. Magnetic resonance imaging features of cerebellar atrophy pattern after epilepsy. ZHONG NAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF CENTRAL SOUTH UNIVERSITY. MEDICAL SCIENCES 2023; 48:691-697. [PMID: 37539571 PMCID: PMC10930401 DOI: 10.11817/j.issn.1672-7347.2023.220481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Indexed: 08/05/2023]
Abstract
OBJECTIVES Clinically, it has been found that some patients with epilepsy are accompanied by cerebellar atrophy that is inconsistent with symptoms, but the pattern of cerebellar atrophy after epilepsy and the role of cerebellar atrophy in the mechanism of epilepsy have not been elucidated. This study aims to explore the specific pattern of cerebellar atrophy after epilepsy via analyzing magnetic resonance images in patients with postepileptic cerebellar atrophy. METHODS A total of 41 patients with epilepsy, who received the treatment in Xiangya Hospital of Central South University from January 2017 to January 2022 and underwent cranial MRI examination, were selected as the case group. The results of cranial MRI examination of all patients showed cerebellar atrophy. In the same period, 41 cases of physical examination were selected as the control group. General clinical data and cranial MRI results of the 2 groups were collected. The maximum area and signal of dentate nucleus, the maximum width of the brachium pontis, the maximum anterior-posterior diameter of the pontine, and the maximum transverse area of the fourth ventricle were compared between the 2 groups. The indexes with difference were further subjected to logistic regression analysis to clarify the characteristic imaging changes in patients with cerebellar atrophy after epilepsy. RESULTS Compared with the control group, the maximum width of the brachium pontis and the maximum anterior-posterior diameter of the pontine were decreased significantly, the maximum transverse area of the fourth ventricle was increased significantly in the case group (all P<0.05). The difference in distribution of the low, equal, and high signal in dentate nucleus between the 2 groups was statistically significant (χ2=43.114, P<0.001), and the difference in the maximum area of dentate nucleus between the 2 groups was not significant (P>0.05). The maximum width of the brachium pontis [odds ratio (OR)=3.327, 95% CI 1.454 to 7.615, P=0.004] and the maximum transverse area of the fourth ventricle (OR=0.987, 95% CI 0.979 to 0.995, P=0.002) were independent factors that distinguished cerebellar atrophy after epilepsy from the normal control, while the anterior-posterior diameter of pontine (OR=1.456, 95% CI 0.906 to 2.339, P>0.05) was not an independent factor that distinguished them. CONCLUSIONS In MRI imaging, cerebellar atrophy after epilepsy is manifested as significant atrophy of the brachium pontis, significant enlargement of the fourth ventricle, and increased dentate nucleus signaling while insignificant dentate nucleus atrophy. This particular pattern may be associated with seizures and exacerbated pathological processes.
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Affiliation(s)
- Ximei Feng
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China.
| | - Qian Wang
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Hong Jin
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Shuai Yang
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Wu Xing
- Department of Radiology, Xiangya Hospital, Central South University, Changsha 410008, China.
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Streng ML, Froula JM, Krook-Magnuson E. The cerebellum's understated role and influences in the epilepsies. Neurobiol Dis 2023; 183:106160. [PMID: 37209926 DOI: 10.1016/j.nbd.2023.106160] [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: 02/28/2023] [Revised: 05/03/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023] Open
Abstract
Approximately 1 in 26 people will develop epilepsy in their lifetime, but current treatment options leave as many as half of all epilepsy patients with uncontrolled seizures. In addition to the burden of the seizures themselves, chronic epilepsy can be associated with cognitive deficits, structural changes, and devastating negative outcomes such as sudden unexpected death in epilepsy (SUDEP). Thus, major challenges in epilepsy research surround the need to both develop new therapeutic targets for intervention as well as shed light on the mechanisms by which chronic epilepsy can lead to comorbidities and negative outcomes. Despite not being traditionally associated with epilepsy or seizures, the cerebellum has emerged as not only a brain region that can serve as an important target for seizure control, but one that may also be profoundly impacted by chronic epilepsy. Here, we discuss targeting the cerebellum for potential therapeutic intervention and discuss pathway insights gained from recent optogenetic studies. We then review observations of cerebellar alterations during seizures and in chronic epilepsy, as well as the potential for the cerebellum to be a seizure focus. Cerebellar alterations in epilepsy may be critical to patient outcomes, highlighting the need for a more comprehensive understanding and appreciation of the cerebellum in the epilepsies.
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Affiliation(s)
- Martha L Streng
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA.
| | - Jessica M Froula
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
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Stieve BJ, Smith MM, Krook-Magnuson E. LINCs Are Vulnerable to Epileptic Insult and Fail to Provide Seizure Control via On-Demand Activation. eNeuro 2023; 10:ENEURO.0195-22.2022. [PMID: 36725340 PMCID: PMC9933934 DOI: 10.1523/eneuro.0195-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 02/03/2023] Open
Abstract
Temporal lobe epilepsy (TLE) is notoriously pharmacoresistant, and identifying novel therapeutic targets for controlling seizures is crucial. Long-range inhibitory neuronal nitric oxide synthase-expressing cells (LINCs), a population of hippocampal neurons, were recently identified as a unique source of widespread inhibition in CA1, able to elicit both GABAA-mediated and GABAB-mediated postsynaptic inhibition. We therefore hypothesized that LINCs could be an effective target for seizure control. LINCs were optogenetically activated for on-demand seizure intervention in the intrahippocampal kainate (KA) mouse model of chronic TLE. Unexpectedly, LINC activation at 1 month post-KA did not substantially reduce seizure duration in either male or female mice. We tested two different sets of stimulation parameters, both previously found to be effective with on-demand optogenetic approaches, but neither was successful. Quantification of LINCs following intervention revealed a substantial reduction of LINC numbers compared with saline-injected controls. We also observed a decreased number of LINCs when the site of initial insult (i.e., KA injection) was moved to the amygdala [basolateral amygdala (BLA)-KA], and correspondingly, no effect of light delivery on BLA-KA seizures. This indicates that LINCs may be a vulnerable population in TLE, regardless of the site of initial insult. To determine whether long-term circuitry changes could influence outcomes, we continued testing once a month for up to 6 months post-KA. However, at no time point did LINC activation provide meaningful seizure suppression. Altogether, our results suggest that LINCs are not a promising target for seizure inhibition in TLE.
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Affiliation(s)
- Bethany J Stieve
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
| | - Madison M Smith
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
| | - Esther Krook-Magnuson
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
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Lisgaras CP, Oliva A, Mckenzie S, LaFrancois J, Siegelbaum SA, Scharman HE. Hippocampal area CA2 controls seizure dynamics, interictal EEG abnormalities and social comorbidity in mouse models of temporal lobe epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.15.524149. [PMID: 36711983 PMCID: PMC9882187 DOI: 10.1101/2023.01.15.524149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Temporal lobe epilepsy (TLE) is characterized by spontaneous recurrent seizures, abnormal activity between seizures, and impaired behavior. CA2 pyramidal neurons (PNs) are potentially important because inhibiting them with a chemogenetic approach reduces seizure frequency in a mouse model of TLE. However, whether seizures could be stopped by timing inhibition just as a seizure begins is unclear. Furthermore, whether inhibition would reduce the cortical and motor manifestations of seizures are not clear. Finally, whether interictal EEG abnormalities and TLE comorbidities would be improved are unknown. Therefore, real-time optogenetic silencing of CA2 PNs during seizures, interictal activity and behavior were studied in 2 mouse models of TLE. CA2 silencing significantly reduced seizure duration and time spent in convulsive behavior. Interictal spikes and high frequency oscillations were significantly reduced, and social behavior was improved. Therefore, brief focal silencing of CA2 PNs reduces seizures, their propagation, and convulsive manifestations, improves interictal EEG, and ameliorates social comorbidities. HIGHLIGHTS Real-time CA2 silencing at the onset of seizures reduces seizure durationWhen CA2 silencing reduces seizure activity in hippocampus it also reduces cortical seizure activity and convulsive manifestations of seizuresInterictal spikes and high frequency oscillations are reduced by real-time CA2 silencingReal-time CA2 silencing of high frequency oscillations (>250Hz) rescues social memory deficits of chronic epileptic mice.
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Stieve BJ, Richner TJ, Krook-Magnuson C, Netoff TI, Krook-Magnuson E. Optimization of closed-loop electrical stimulation enables robust cerebellar-directed seizure control. Brain 2023; 146:91-108. [PMID: 35136942 DOI: 10.1093/brain/awac051] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 12/17/2021] [Accepted: 01/11/2022] [Indexed: 01/11/2023] Open
Abstract
Additional treatment options for temporal lobe epilepsy are needed, and potential interventions targeting the cerebellum are of interest. Previous animal work has shown strong inhibition of hippocampal seizures through on-demand optogenetic manipulation of the cerebellum. However, decades of work examining electrical stimulation-a more immediately translatable approach-targeting the cerebellum has produced very mixed results. We were therefore interested in exploring the impact that stimulation parameters may have on seizure outcomes. Using a mouse model of temporal lobe epilepsy, we conducted on-demand electrical stimulation of the cerebellar cortex, and varied stimulation charge, frequency and pulse width, resulting in over 1000 different potential combinations of settings. To explore this parameter space in an efficient, data-driven, manner, we utilized Bayesian optimization with Gaussian process regression, implemented in MATLAB with an Expected Improvement Plus acquisition function. We examined three different fitting conditions and two different electrode orientations. Following the optimization process, we conducted additional on-demand experiments to test the effectiveness of selected settings. Regardless of experimental setup, we found that Bayesian optimization allowed identification of effective intervention settings. Additionally, generally similar optimal settings were identified across animals, suggesting that personalized optimization may not always be necessary. While optimal settings were effective, stimulation with settings predicted from the Gaussian process regression to be ineffective failed to provide seizure control. Taken together, our results provide a blueprint for exploration of a large parameter space for seizure control and illustrate that robust inhibition of seizures can be achieved with electrical stimulation of the cerebellum, but only if the correct stimulation parameters are used.
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Affiliation(s)
- Bethany J Stieve
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis 55455, USA
| | - Thomas J Richner
- Department of Biomedical Engineering, University of Minnesota, Minneapolis 55455, USA.,Department of Neuroscience, University of Minnesota, Minneapolis 55455, USA
| | | | - Theoden I Netoff
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis 55455, USA.,Department of Biomedical Engineering, University of Minnesota, Minneapolis 55455, USA
| | - Esther Krook-Magnuson
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis 55455, USA.,Department of Neuroscience, University of Minnesota, Minneapolis 55455, USA
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Froula JM, Hastings SD, Krook-Magnuson E. The little brain and the seahorse: Cerebellar-hippocampal interactions. Front Syst Neurosci 2023; 17:1158492. [PMID: 37034014 PMCID: PMC10076554 DOI: 10.3389/fnsys.2023.1158492] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
There is a growing appreciation for the cerebellum beyond its role in motor function and accumulating evidence that the cerebellum and hippocampus interact across a range of brain states and behaviors. Acute and chronic manipulations, simultaneous recordings, and imaging studies together indicate coordinated coactivation and a bidirectional functional connectivity relevant for various physiological functions, including spatiotemporal processing. This bidirectional functional connectivity is likely supported by multiple circuit paths. It is also important in temporal lobe epilepsy: the cerebellum is impacted by seizures and epilepsy, and modulation of cerebellar circuitry can be an effective strategy to inhibit hippocampal seizures. This review highlights some of the recent key hippobellum literature.
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Richardson A, Morris G. Cross Talk opposing view: Animal models of epilepsy are more useful than human tissue-based approaches. J Physiol 2022; 600:4575-4578. [PMID: 36148995 DOI: 10.1113/jp282186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 06/22/2022] [Indexed: 12/13/2022] Open
Affiliation(s)
- Amy Richardson
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Gareth Morris
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.,Department of Physiology and Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland.,FutureNeuro, the SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine & Health Sciences
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14
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Leaver AM, Espinoza R, Wade B, Narr KL. Parsing the Network Mechanisms of Electroconvulsive Therapy. Biol Psychiatry 2022; 92:193-203. [PMID: 35120710 PMCID: PMC9196257 DOI: 10.1016/j.biopsych.2021.11.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 11/03/2021] [Accepted: 11/19/2021] [Indexed: 12/17/2022]
Abstract
Electroconvulsive therapy (ECT) is one of the oldest and most effective forms of neurostimulation, wherein electrical current is used to elicit brief, generalized seizures under general anesthesia. When electrodes are positioned to target frontotemporal cortex, ECT is arguably the most effective treatment for severe major depression, with response rates and times superior to other available antidepressant therapies. Neuroimaging research has been pivotal in improving the field's mechanistic understanding of ECT, with a growing number of magnetic resonance imaging studies demonstrating hippocampal plasticity after ECT, in line with evidence of upregulated neurotrophic processes in the hippocampus in animal models. However, the precise roles of the hippocampus and other brain regions in antidepressant response to ECT remain unclear. Seizure physiology may also play a role in antidepressant response to ECT, as indicated by early positron emission tomography, single-photon emission computed tomography, and electroencephalography research and corroborated by recent magnetic resonance imaging studies. In this review, we discuss the evidence supporting neuroplasticity in the hippocampus and other brain regions during and after ECT, and their associations with antidepressant response. We also offer a mechanistic, circuit-level model that proposes that core mechanisms of antidepressant response to ECT involve thalamocortical and cerebellar networks that are active during seizure generalization and termination over repeated ECT sessions, and their interactions with corticolimbic circuits that are dysfunctional prior to treatment and targeted with the electrical stimulus.
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Affiliation(s)
- Amber M Leaver
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Evanston, Illinois.
| | - Randall Espinoza
- Department of Psychiatry and Behavioral Sciences, Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Benjamin Wade
- Department of Neurology, Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Katherine L Narr
- Department of Neurology, Geffen School of Medicine, University of California Los Angeles, Los Angeles, California; Department of Psychiatry and Behavioral Sciences, Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
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15
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Buchanan GF. Not All Paths are Equal: Stimulating Specific Cerebellar Outputs Inhibits Hippocampal Seizures. Epilepsy Curr 2022; 22:318-320. [PMID: 36285206 PMCID: PMC9549229 DOI: 10.1177/15357597221113706] [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] [Indexed: 11/29/2022] Open
Abstract
Distinct Fastigial Output Channels and Their Impact on Temporal Lobe
Seizures Streng ML, Tetzlaff MR, Krook-Magnuson E. 2021. J. Neurosci.
41(49):10091-10107. doi:10.1523/JNEUROSCI.0683-21.2021. Despite being canonically considered a motor control structure, the cerebellum is
increasingly recognized for important roles in processes beyond this traditional
framework, including seizure suppression. Excitatory fastigial neurons project to a
large number of downstream targets, and it is unclear whether this broad targeting
underlies seizure suppression, or whether a specific output may be sufficient. To
address this question, we used the intrahippocampal kainic acid mouse model of
temporal lobe epilepsy, male and female animals, and a dual-virus approach to
selectively label and manipulate fastigial outputs. We examined fastigial neurons
projecting to the superior colliculus, medullary reticular formation, and central
lateral nucleus of the thalamus, and found that these comprise largely nonoverlapping
populations of neurons that send collaterals to unique sets of additional, somewhat
overlapping, thalamic and brainstem regions. We found that neither optogenetic
stimulation of superior colliculus nor reticular formation output channels attenuated
hippocampal seizures. In contrast, on-demand stimulation of fastigial neurons
targeting the central lateral nucleus robustly inhibited seizures. Our results
indicate that fastigial control of hippocampal seizures does not require simultaneous
modulation of many fastigial output channels. Rather, selective modulation of the
fastigial output channel to the central lateral thalamus, specifically, is sufficient
for seizure control. More broadly, our data highlight the concept of specific
cerebellar output channels, whereby discrete cerebellar nucleus neurons project to
specific aggregates of downstream targets, with important consequences for therapeutic
interventions.
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16
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Liu XX, Chen XH, Zheng ZW, Jiang Q, Li C, Yang L, Chen X, Mao XF, Yuan HY, Feng LL, Jiang Q, Shi WX, Sasaki T, Fukunaga K, Chen Z, Han F, Lu YM. BOD1 regulates the cerebellar IV/V lobe-fastigial nucleus circuit associated with motor coordination. Signal Transduct Target Ther 2022; 7:170. [PMID: 35641478 PMCID: PMC9156688 DOI: 10.1038/s41392-022-00989-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 03/25/2022] [Accepted: 04/06/2022] [Indexed: 11/16/2022] Open
Abstract
Cerebellar ataxias are characterized by a progressive decline in motor coordination, but the specific output circuits and underlying pathological mechanism remain poorly understood. Through cell-type-specific manipulations, we discovered a novel GABAergic Purkinje cell (PC) circuit in the cerebellar IV/V lobe that projected to CaMKIIα+ neurons in the fastigial nucleus (FN), which regulated sensorimotor coordination. Furthermore, transcriptomics profiling analysis revealed various cerebellar neuronal identities, and we validated that biorientation defective 1 (BOD1) played an important role in the circuit of IV/V lobe to FN. BOD1 deficit in PCs of IV/V lobe attenuated the excitability and spine density of PCs, accompany with ataxia behaviors. Instead, BOD1 enrichment in PCs of IV/V lobe reversed the hyperexcitability of CaMKIIα+ neurons in the FN and ameliorated ataxia behaviors in L7-Cre; BOD1f/f mice. Together, these findings further suggest that specific regulation of the cerebellar IV/V lobePCs → FNCaMKIIα+ circuit might provide neuromodulatory targets for the treatment of ataxia behaviors.
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Affiliation(s)
- Xiu-Xiu Liu
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Drug Target and Drug Discovery Center, School of Pharmacy, Nanjing Medical University, 211166, Nanjing, China
| | - Xing-Hui Chen
- Department of Physiology, School of Basic Medical Sciences, Nanjing Medical University, 211166, Nanjing, China.,Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Zhi-Wei Zheng
- Department of Physiology, School of Basic Medical Sciences, Nanjing Medical University, 211166, Nanjing, China
| | - Qin Jiang
- Department of Physiology, School of Basic Medical Sciences, Nanjing Medical University, 211166, Nanjing, China
| | - Chen Li
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Drug Target and Drug Discovery Center, School of Pharmacy, Nanjing Medical University, 211166, Nanjing, China
| | - Lin Yang
- Department of Physiology, School of Basic Medical Sciences, Nanjing Medical University, 211166, Nanjing, China.,Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Xiang Chen
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Drug Target and Drug Discovery Center, School of Pharmacy, Nanjing Medical University, 211166, Nanjing, China
| | - Xing-Feng Mao
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Drug Target and Drug Discovery Center, School of Pharmacy, Nanjing Medical University, 211166, Nanjing, China
| | - Hao-Yang Yuan
- Department of Physiology, School of Basic Medical Sciences, Nanjing Medical University, 211166, Nanjing, China
| | - Li-Li Feng
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Drug Target and Drug Discovery Center, School of Pharmacy, Nanjing Medical University, 211166, Nanjing, China
| | - Quan Jiang
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Wei-Xing Shi
- Department of Pharmaceutical and Administrative Sciences, Loma Linda University School of Pharmacy, Loma Linda, CA, 92350, USA.,Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, 92350, USA
| | - Takuya Sasaki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Zhong Chen
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Feng Han
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Drug Target and Drug Discovery Center, School of Pharmacy, Nanjing Medical University, 211166, Nanjing, China. .,Institute of Brain Science, the Affiliated Brain Hospital of Nanjing Medical University, 210029, Nanjing, China. .,Gusu School, Nanjing Medical University, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, 215002, Suzhou, China.
| | - Ying-Mei Lu
- Department of Physiology, School of Basic Medical Sciences, Nanjing Medical University, 211166, Nanjing, China. .,Institute of Brain Science, the Affiliated Brain Hospital of Nanjing Medical University, 210029, Nanjing, China.
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17
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Schwitalla JC, Pakusch J, Mücher B, Brückner A, Depke DA, Fenzl T, De Zeeuw CI, Kros L, Hoebeek FE, Mark MD. Controlling absence seizures from the cerebellar nuclei via activation of the G q signaling pathway. Cell Mol Life Sci 2022; 79:197. [PMID: 35305155 PMCID: PMC8934336 DOI: 10.1007/s00018-022-04221-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 01/27/2022] [Accepted: 02/23/2022] [Indexed: 11/28/2022]
Abstract
Absence seizures (ASs) are characterized by pathological electrographic oscillations in the cerebral cortex and thalamus, which are called spike-and-wave discharges (SWDs). Subcortical structures, such as the cerebellum, may well contribute to the emergence of ASs, but the cellular and molecular underpinnings remain poorly understood. Here we show that the genetic ablation of P/Q-type calcium channels in cerebellar granule cells (quirky) or Purkinje cells (purky) leads to recurrent SWDs with the purky model showing the more severe phenotype. The quirky mouse model showed irregular action potential firing of their cerebellar nuclei (CN) neurons as well as rhythmic firing during the wave of their SWDs. The purky model also showed irregular CN firing, in addition to a reduced firing rate and rhythmicity during the spike of the SWDs. In both models, the incidence of SWDs could be decreased by increasing CN activity via activation of the Gq-coupled designer receptor exclusively activated by designer drugs (DREADDs) or via that of the Gq-coupled metabotropic glutamate receptor 1. In contrast, the incidence of SWDs was increased by decreasing CN activity via activation of the inhibitory Gi/o-coupled DREADD. Finally, disrupting CN rhythmic firing with a closed-loop channelrhodopsin-2 stimulation protocol confirmed that ongoing SWDs can be ceased by activating CN neurons. Together, our data highlight that P/Q-type calcium channels in cerebellar granule cells and Purkinje cells can be relevant for epileptogenesis, that Gq-coupled activation of CN neurons can exert anti-epileptic effects and that precisely timed activation of the CN can be used to stop ongoing SWDs.
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Affiliation(s)
| | - Johanna Pakusch
- Department of Behavioral Neuroscience, Ruhr-University Bochum, 44801, Bochum, Germany
| | - Brix Mücher
- Department of Zoology and Neurobiology, Ruhr-University Bochum, 44801, Bochum, Germany
| | - Alexander Brückner
- Institute of Physiology I, Medical Faculty, University of Bonn, 53127, Bonn, Germany
| | - Dominic Alexej Depke
- European Institute of Molecular Imaging, University of Münster, 48149, Münster, Germany
| | - Thomas Fenzl
- Department of Anesthesiology and Intensive Care, TUM School of Medicine, Technical University of Munich, 81675, Munich, Germany
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, 3015 AA, Rotterdam, The Netherlands.,Netherlands Institute for Neuroscience, Royal Dutch Academy for Arts and Sciences, 1105, BA, Amsterdam, The Netherlands
| | - Lieke Kros
- Department of Neuroscience, Erasmus MC, 3015 AA, Rotterdam, The Netherlands
| | - Freek E Hoebeek
- Department for Developmental Origins of Disease, Wilhelmina Children's Hospital and Brain Center, University Medical Center Utrecht, 3584 EA, Utrecht, The Netherlands
| | - Melanie D Mark
- Department of Behavioral Neuroscience, Ruhr-University Bochum, 44801, Bochum, Germany.
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18
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Nie L, Jiang Y, Lv Z, Pang X, Liang X, Chang W, Zheng J. A study of brain functional network and alertness changes in temporal lobe epilepsy with and without focal to bilateral tonic-clonic seizures. BMC Neurol 2022; 22:14. [PMID: 34996377 PMCID: PMC8740350 DOI: 10.1186/s12883-021-02525-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 12/13/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Temporal lobe epilepsy (TLE) is commonly refractory. Epilepsy surgery is an effective treatment strategy for refractory epilepsy, but patients with a history of focal to bilateral tonic-clonic seizures (FBTCS) have poor outcomes. Previous network studies on epilepsy have found that TLE and idiopathic generalized epilepsy with generalized tonic-clonic seizures (IGE-GTCS) showed altered global and nodal topological properties. Alertness deficits also were found in TLE. However, FBTCS is a common type of seizure in TLE, and the implications for alertness as well as the topological rearrangements associated with this seizure type are not well understood. METHODS We obtained rs-fMRI data and collected the neuropsychological assessment data from 21 TLE patients with FBTCS (TLE- FBTCS), 18 TLE patients without FBTCS (TLE-non- FBTCS) and 22 controls, and constructed their respective functional brain networks. The topological properties were analyzed using the graph theoretical approach and correlations between altered topological properties and alertness were analyzed. RESULTS We found that TLE-FBTCS patients showed more serious impairment in alertness effect, intrinsic alertness and phasic alertness than the patients with TLE-non-FBTCS. They also showed significantly higher small-worldness, normalized clustering coefficient (γ) and a trend of higher global network efficiency (gE) compared to TLE-non-FBTCS patients. The gE showed a significant negative correlation with intrinsic alertness for TLE-non-FBTCS patients. CONCLUSION Our findings show different impairments in brain network information integration, segregation and alertness between the patients with TLE-FBTCS and TLE-non-FBTCS, demonstrating that impairments of the brain network may underlie the disruptions in alertness functions.
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Affiliation(s)
- Liluo Nie
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, No.6, Shuangyong Road, Nanning, 530021, China
| | - Yanchun Jiang
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, No.6, Shuangyong Road, Nanning, 530021, China
| | - Zongxia Lv
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, No.6, Shuangyong Road, Nanning, 530021, China
| | - Xiaomin Pang
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, No.6, Shuangyong Road, Nanning, 530021, China
| | - Xiulin Liang
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, No.6, Shuangyong Road, Nanning, 530021, China
| | - Weiwei Chang
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, No.6, Shuangyong Road, Nanning, 530021, China
| | - Jinou Zheng
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, No.6, Shuangyong Road, Nanning, 530021, China.
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19
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Transcranial direct current stimulation of cerebellum alters spiking precision in cerebellar cortex: A modeling study of cellular responses. PLoS Comput Biol 2021; 17:e1009609. [PMID: 34882680 PMCID: PMC8691604 DOI: 10.1371/journal.pcbi.1009609] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 12/21/2021] [Accepted: 11/02/2021] [Indexed: 01/13/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) of the cerebellum has rapidly raised interest but the effects of tDCS on cerebellar neurons remain unclear. Assessing the cellular response to tDCS is challenging because of the uneven, highly stratified cytoarchitecture of the cerebellum, within which cellular morphologies, physiological properties, and function vary largely across several types of neurons. In this study, we combine MRI-based segmentation of the cerebellum and a finite element model of the tDCS-induced electric field (EF) inside the cerebellum to determine the field imposed on the cerebellar neurons throughout the region. We then pair the EF with multicompartment models of the Purkinje cell (PC), deep cerebellar neuron (DCN), and granule cell (GrC) and quantify the acute response of these neurons under various orientations, physiological conditions, and sequences of presynaptic stimuli. We show that cerebellar tDCS significantly modulates the postsynaptic spiking precision of the PC, which is expressed as a change in the spike count and timing in response to presynaptic stimuli. tDCS has modest effects, instead, on the PC tonic firing at rest and on the postsynaptic activity of DCN and GrC. In Purkinje cells, anodal tDCS shortens the repolarization phase following complex spikes (-14.7 ± 6.5% of baseline value, mean ± S.D.; max: -22.7%) and promotes burstiness with longer bursts compared to resting conditions. Cathodal tDCS, instead, promotes irregular spiking by enhancing somatic excitability and significantly prolongs the repolarization after complex spikes compared to baseline (+37.0 ± 28.9%, mean ± S.D.; max: +84.3%). tDCS-induced changes to the repolarization phase and firing pattern exceed 10% of the baseline values in Purkinje cells covering up to 20% of the cerebellar cortex, with the effects being distributed along the EF direction and concentrated in the area under the electrode over the cerebellum. Altogether, the acute effects of tDCS on cerebellum mainly focus on Purkinje cells and modulate the precision of the response to synaptic stimuli, thus having the largest impact when the cerebellar cortex is active. Since the spatiotemporal precision of the PC spiking is critical to learning and coordination, our results suggest cerebellar tDCS as a viable therapeutic option for disorders involving cerebellar hyperactivity such as ataxia. Transcranial direct current stimulation (tDCS) of the cerebellum is gaining momentum as a neuromodulation tool for the treatment of neurological diseases like movement disorders. Nonetheless, the response of cells in the cerebellum to tDCS is unclear and hardly generalizes from our understanding of tDCS of the cerebral cortex. We use computational models to investigate the response of several types of cerebellar neurons to the electric field induced by tDCS and show that, differently from the cerebral cortex, tDCS has significant acute effects on the cerebellar cortex. These effects (i) primarily alter the way Purkinje cells encode synaptic stimuli from the molecular layer and (ii) can help hyperactive cells regain postsynaptic spiking precision. Since the spatiotemporal precision of the Purkinje cell spiking is critical to learning and coordination, the study shows how tDCS can operate at the cellular level to treat movement disorders like tremor and ataxia.
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20
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Distinct Fastigial Output Channels and Their Impact on Temporal Lobe Seizures. J Neurosci 2021; 41:10091-10107. [PMID: 34716233 DOI: 10.1523/jneurosci.0683-21.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/07/2021] [Accepted: 10/22/2021] [Indexed: 01/07/2023] Open
Abstract
Despite being canonically considered a motor control structure, the cerebellum is increasingly recognized for important roles in processes beyond this traditional framework, including seizure suppression. Excitatory fastigial neurons project to a large number of downstream targets, and it is unclear whether this broad targeting underlies seizure suppression, or whether a specific output may be sufficient. To address this question, we used the intrahippocampal kainic acid mouse model of temporal lobe epilepsy, male and female animals, and a dual-virus approach to selectively label and manipulate fastigial outputs. We examined fastigial neurons projecting to the superior colliculus, medullary reticular formation, and central lateral nucleus of the thalamus, and found that these comprise largely nonoverlapping populations of neurons that send collaterals to unique sets of additional, somewhat overlapping, thalamic and brainstem regions. We found that neither optogenetic stimulation of superior colliculus nor reticular formation output channels attenuated hippocampal seizures. In contrast, on-demand stimulation of fastigial neurons targeting the central lateral nucleus robustly inhibited seizures. Our results indicate that fastigial control of hippocampal seizures does not require simultaneous modulation of many fastigial output channels. Rather, selective modulation of the fastigial output channel to the central lateral thalamus, specifically, is sufficient for seizure control. More broadly, our data highlight the concept of specific cerebellar output channels, whereby discrete cerebellar nucleus neurons project to specific aggregates of downstream targets, with important consequences for therapeutic interventions.SIGNIFICANCE STATEMENT The cerebellum has an emerging relationship with nonmotor systems and may represent a powerful target for therapeutic intervention in temporal lobe epilepsy. We find, as previously reported, that fastigial neurons project to numerous brain regions via largely segregated output channels, and that projection targets cannot be predicted simply by somatic locations within the nucleus. We further find that on-demand optogenetic excitation of fastigial neurons projecting to the central lateral nucleus of the thalamus-but not fastigial neurons projecting to the reticular formation, superior colliculus, or ventral lateral thalamus-is sufficient to attenuate hippocampal seizures.
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21
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Abstract
SUMMARY Electrical brain stimulation is an established therapy for movement disorders, epilepsy, obsessive compulsive disorder, and a potential therapy for many other neurologic and psychiatric disorders. Despite significant progress and FDA approvals, there remain significant clinical gaps that can be addressed with next generation systems. Integrating wearable sensors and implantable brain devices with off-the-body computing resources (smart phones and cloud resources) opens a new vista for dense behavioral and physiological signal tracking coupled with adaptive stimulation therapy that should have applications for a range of brain and mind disorders. Here, we briefly review some history and current electrical brain stimulation applications for epilepsy, deep brain stimulation and responsive neurostimulation, and emerging applications for next generation devices and systems.
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Affiliation(s)
- Gregory A Worrell
- Department of Neurology, Mayo Bioelectronics and Neurophysiology Laboratory, Mayo Clinic, Rochester, Minnesota, U.S.A
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22
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Harper RM, Hertling D, Curtis A, Sauerland EK, De Giorgio CM. Pilot Safety and Feasibility Study of Non-invasive Limb Proprioceptive Cerebellar Stimulation for Epilepsy. Front Neurol 2021; 12:675947. [PMID: 34484096 PMCID: PMC8415900 DOI: 10.3389/fneur.2021.675947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 07/19/2021] [Indexed: 12/17/2022] Open
Abstract
Cerebellar stimulation reduces seizures in animals and in humans with drug-resistant epilepsy. In a pilot safety and feasibility study, we applied continuous cutaneous vibratory stimulation (limb proprioceptive cerebellar stimulation) to foot limb proprioceptive receptors to activate cerebellar, pontine, and thalamic structures in drug-resistant epilepsy patients for 8-h nocturnally up to 6-months after a 4-week pre-treatment control baseline. Seizure frequency was evaluated during the baseline control period, and at 6, 12, and 24 weeks after the control recordings. Five-subjects completed at least the first 6-week treatment. At 12-weeks, the median reduction in seizure frequency was -27.8% (mean reduction = -22.3%). Two subjects continued for 24 weeks, with a decline of -44.1 and -45.4%. This pilot study provides support for further clinical studies into the safety and efficacy of limb proprioceptive cerebellar stimulation for epilepsy.
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Affiliation(s)
- Ronald M. Harper
- Department of Neurobiology, David Geffen School of Medicine, Univeersity of California, Los Angeles, Los Angeles, CA, United States
| | - Dieter Hertling
- Department of Neurology, Olive View Medical Center, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Ashley Curtis
- Department of Neurology, Olive View Medical Center, University of California, Los Angeles, Los Angeles, CA, United States
| | | | - Christopher M. De Giorgio
- Department of Neurology, Olive View Medical Center, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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23
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Abstract
Epilepsy is the fourth most common neurological disorder, but current treatment options provide limited efficacy and carry the potential for problematic adverse effects. There is an immense need to develop new therapeutic interventions in epilepsy, and targeting areas outside the seizure focus for neuromodulation has shown therapeutic value. While not traditionally associated with epilepsy, anatomical, clinical, and electrophysiological studies suggest the cerebellum can play a role in seizure networks, and importantly, may be a potential therapeutic target for seizure control. However, previous interventions targeting the cerebellum in both preclinical and clinical studies have produced mixed effects on seizures. These inconsistent results may be due in part to the lack of specificity inherent with open-loop electrical stimulation interventions. More recent studies, using more targeted closed-loop optogenetic approaches, suggest the possibility of robust seizure inhibition via cerebellar modulation for a range of seizure types. Therefore, while the mechanisms of cerebellar inhibition of seizures have yet to be fully elucidated, the cerebellum should be thoroughly revisited as a potential target for therapeutic intervention in epilepsy. This article is part of the Special Issue "NEWroscience 2018.
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24
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Akyuz E, Ozenen C, Pinyazhko OR, Poshyvak OB, Godlevsky LS. Cerebellar contribution to absence epilepsy. Neurosci Lett 2021; 761:136110. [PMID: 34256107 DOI: 10.1016/j.neulet.2021.136110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/18/2021] [Accepted: 06/23/2021] [Indexed: 10/20/2022]
Abstract
The new aggregate data analyses revealed the earlier missing role of cerebellum long-term electrical stimulation in the absence epilepsy. Neurophysiologic data gained by authors favor that cerebellar serial deep brain stimulation (DBS) (100 Hz) causes the transformation of penicillin-induced cortical focal discharges into prolonged 3,5-3,75 sec oscillations resembling spike-wave discharges (SWD) in cats. Such SWDs were not organized in the form of bursts and persisted continuously after stimulation. Therefore, the appearance of prolonged periods of SWD is regarded as a tonic cerebellar influence upon pacemaker of SWD and might be caused by the long-lasting DBS-induced increase of GABA-ergic extrasynaptic inhibition in the forebrain networks. The absence seizure facilitation caused by cerebellar DBS was discussed with the reviewed data on optogenetic stimulation, neuronal activity of cerebellar structures, and imaging data.
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Affiliation(s)
- Enes Akyuz
- Department of Biophysics, Faculty of International Medicine, University of Health Sciences, Istanbul, Turkey.
| | - Cansu Ozenen
- Bolu Abant Izzet Baysal University, Faculty of Medicine, Bolu, Turkey
| | - Oleh R Pinyazhko
- Pharmacology Department, Danylo Halytsky Lviv National Medical University, Lviv, Ukraine; Department of Civilization Diseases and Regenerative Medicine, WSIiZ, Rzeszow, Poland
| | - Olesya B Poshyvak
- Pharmacology Department, Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Leonid S Godlevsky
- Department of Biophysics, Informatics and Medical Devices, Odesa National Medical University, 2, Valikhovsky Lane, Odesa 65082, Ukraine.
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25
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Nie L, Jiang Y, Lv Z, Pang X, Liang X, Chang W, Li J, Zheng J. Deep Cerebellar Nuclei Functional Connectivity with Cerebral Cortex in Temporal Lobe Epilepsy With and Without Focal to Bilateral Tonic-Clonic Seizures: a Resting-State fMRI Study. THE CEREBELLUM 2021; 21:253-263. [PMID: 34164777 DOI: 10.1007/s12311-021-01266-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/29/2021] [Indexed: 12/19/2022]
Abstract
We aimed to explore the altered functional connectivity patterns within cerebello-cerebral circuits in temporal lobe epilepsy (TLE) patients with and without focal to bilateral tonic-clonic seizures (FBTCS). Forty-two patients with unilateral TLE (21 with and 21 without FBTCS) and 22 healthy controls were recruited. We chose deep cerebellar nuclei as seed regions, calculated static and dynamic functional connectivity (sFC and dFC) in the patients with and without FBTCS and healthy controls, and compared sFC and dFC among the three groups. Correlation analyses were used to assess relationships between the significantly altered imaging features and patient clinical parameters. Compared to the group without FBTCS, the FBTCS group showed decreased sFC between the right dentate nuclei and left hemisphere regions including the middle frontal gyrus, superior temporal gyrus, superior medial frontal gyrus and posterior cingulate gyrus, and significantly increased dFC between the right interposed nuclei and contralateral precuneus. Relative to HCs, the FBTCS group demonstrated prominently decreased sFC between the right dentate nuclei and left middle frontal gyrus. No significant correlations between the altered imaging features and patient clinical parameters were observed. Our results suggest that the disrupted cerebello-cerebral FC might be related to cognitive impairment, epileptogenesis, and propagation of epileptic activities in patients with FBTCS.
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Affiliation(s)
- Liluo Nie
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Yanchun Jiang
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Zongxia Lv
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xiaomin Pang
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xiulin Liang
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Weiwei Chang
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jian Li
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jinou Zheng
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China.
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de Oliveira TVHF, Cukiert A. Deep Brain Stimulation for Treatment of Refractory Epilepsy. Neurol India 2021; 68:S268-S277. [PMID: 33318361 DOI: 10.4103/0028-3886.302454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Deep brain stimulation (DBS) has been used in the treatment of motor diseases with remarkable safety and efficacy, which abet the interest of its application in the management of other neurologic and psychiatric disorders such as epilepsy. Experimental data demonstrated that electric current could modulate distinct brain circuits and decrease the neuronal hypersynchronization seen in epileptic activity. The ability to carefully choose the most suitable anatomical target as well as to define the most reasonable stimulation parameters is highly dependable on the comprehension of the underlying mechanisms of action, which remain unclear. This review aimed to explore the relevant clinical data regarding the use of DBS in the treatment of refractory epilepsy.
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Affiliation(s)
| | - Arthur Cukiert
- Department of Neurosurgery, Epilepsy Surgery Program, Clínica Cukiert, São Paulo, Brazil
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Jobst BC, Conner KR, Coulter D, Fried I, Guilfoyle S, Hirsch LJ, Hogan RE, Hopp JL, Naritoku D, Plueger M, Schevon C, Smith G, Valencia I, Gaillard WD. Highlights From AES2020, a Virtual American Epilepsy Society Experience. Epilepsy Curr 2021; 21:15357597211018219. [PMID: 33998298 PMCID: PMC8512915 DOI: 10.1177/15357597211018219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Due to COVID-19 a live, in-person meeting was not possible for the American Epilepsy Society in 2020. An alternative, virtual event, the AES2020, was held instead. AES2020 was a great success with 4679 attendees from 70 countries. The educational content was outstanding and spanned the causes, treatments, and outcomes from epileptic encephalopathy to the iatrogenicity of epilepsy interventions to neurocognitive disabilities to the approach to neocortical epilepsies. New gene therapy approaches such as antisense oligonucleotide treatment for Dravet syndrome were introduced and neuromodulation devices were discussed. There were many other topics discussed in special interest groups and investigators' workshops. A highlight was having a Nobel prize winner speak about memory processing. Human intracranial electrophysiology contributes insights into memory processing and complements animal work. In a special COVID symposium, the impact of COVID on patients with epilepsy was reviewed. Telehealth has been expanded rapidly and may be well suited for some parts of epilepsy care. In summary, the epilepsy community was alive and engaged despite being limited to a virtual platform.
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Affiliation(s)
| | | | | | | | - Shanna Guilfoyle
- Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
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Davis KA, Jirsa VK, Schevon CA. Wheels Within Wheels: Theory and Practice of Epileptic Networks. Epilepsy Curr 2021; 21:15357597211015663. [PMID: 33988042 PMCID: PMC8512917 DOI: 10.1177/15357597211015663] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Kathryn A. Davis
- Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Viktor K. Jirsa
- Aix-Marseille Universite, Marseille, Provence-Alpes-Cote d’Azu, France
- INSERM, Paris, Ile-de-France, France
- Institute de Neurosciences des Systemes,
Marseille, Provence-Alpes-Cote d’Azu, France
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Possible contribution of cerebellar disinhibition in epilepsy. Epilepsy Behav 2021; 118:107944. [PMID: 33887658 DOI: 10.1016/j.yebeh.2021.107944] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 02/07/2023]
Abstract
OBJECTIVE We hypothesize that loss of inhibition from the cerebellum can lead to cortical activation and seizures. BACKGROUND The traditional model for development of seizures purports that the source of seizures is increased electrical activity originating from cerebral cortical neurons. Studies have shown a decrease in inhibition results in a shift of cortical activity to a hyperexcitable state, which may lead to seizures. Interestingly, a 1978 study suggested the term "disorder of disinhibition" as a way to describe epilepsy from studies of chronic cerebellar stimulation. DESIGN/METHODS Cases and experimental studies in which cerebellar lesions have been implicated in the development of seizures were reviewed. Cases in which cerebellar inhibition has been targeted in the treatment of seizures were also included. Twenty-six studies and case reports are presented for this report. RESULTS The cases show cerebellar lesions can lead to cortical epileptiform activity. Purkinje cell loss is linked to the occurrence of seizures in animals. The majority of patients with cerebellar lesions were seizure free after complete resection, while less than half of patients were seizure free after partial resection. Novel treatments using deep-brain stimulation targeting cerebellar structures demonstrated therapeutic benefits for seizures. CONCLUSIONS Although pathophysiology is not well-understood, the cerebellum likely plays an inherent role in inhibiting aberrant cortical epileptogenesis. Cerebellar lesions may cause seizures due to loss of the inhibition of cortical areas or through intrinsic epileptic activity. Treatments enhancing cerebellar stimulation have shown therapeutic benefits in treating seizures, which could potentially provide another avenue for treatment.
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Denison T, Koubeissi M, Krook-Magnuson E, Mogul D, Worrell G, Schevon C. Stimulating Solutions for Intractable Epilepsy. Epilepsy Curr 2021; 21:15357597211012466. [PMID: 33926248 PMCID: PMC8655249 DOI: 10.1177/15357597211012466] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Implantable devices for controlling medically intractable seizures nondestructively are rapidly advancing. These offer reversible, potentially, restorative options beyond traditional, surgical procedures, which rely, largely on resection or ablation of selected brain sites. Several lines of, investigation aimed at improving efficacy of these devices are discussed, ranging from identifying novel subcortical, white matter, or cell-type specific targets to engineering advances for adaptive techniques based- on continuous, dynamic system analysis.
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Affiliation(s)
- Timothy Denison
- Institute of Biomedical Engineering and MRC
Brain Network Dynamics Unit, University of Oxford, Northern Ireland, United Kingdom
| | - Mohamad Koubeissi
- Department of Neurology, George Washington
University, Washington, DC, USA
| | | | - David Mogul
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | | | - Catherine Schevon
- Department of Neurology, Columbia University, New York City, NY, USA
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Chan F, Liu J. Molecular regulation of brain metabolism underlying circadian epilepsy. Epilepsia 2021; 62 Suppl 1:S32-S48. [PMID: 33395505 DOI: 10.1111/epi.16796] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 12/01/2020] [Accepted: 12/01/2020] [Indexed: 12/13/2022]
Abstract
Extensive study has demonstrated that epilepsy occurs with greater frequency at certain times in the 24-h cycle. Although these findings implicate an overlap between the circadian rhythm and epilepsy, the molecular and cellular mechanisms underlying this circadian regulation are poorly understood. Because the 24-h rhythm is generated by the circadian molecular system, it is not surprising that this system comprised of many circadian genes is implicated in epilepsy. We summarized evidence in the literature implicating various circadian genes such as Clock, Bmal1, Per1, Rev-erb⍺, and Ror⍺ in epilepsy. In various animal models of epilepsy, the circadian oscillation and the steady-state level of these genes are disrupted. The downstream pathway of these genes involves a large number of metabolic pathways associated with epilepsy. These pathways include pyridoxal metabolism, the mammalian target of rapamycin pathway, and the regulation of redox state. We propose that disruption of these metabolic pathways could mediate the circadian regulation of epilepsy. A greater understanding of the cellular and molecular mechanism of circadian regulation of epilepsy would enable us to precisely target the circadian disruption in epilepsy for a novel therapeutic approach.
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Affiliation(s)
- Felix Chan
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, USA
| | - Judy Liu
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, USA.,Department of Neurology, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA
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The Optogenetic Revolution in Cerebellar Investigations. Int J Mol Sci 2020; 21:ijms21072494. [PMID: 32260234 PMCID: PMC7212757 DOI: 10.3390/ijms21072494] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 03/30/2020] [Accepted: 04/01/2020] [Indexed: 12/13/2022] Open
Abstract
The cerebellum is most renowned for its role in sensorimotor control and coordination, but a growing number of anatomical and physiological studies are demonstrating its deep involvement in cognitive and emotional functions. Recently, the development and refinement of optogenetic techniques boosted research in the cerebellar field and, impressively, revolutionized the methodological approach and endowed the investigations with entirely new capabilities. This translated into a significant improvement in the data acquired for sensorimotor tests, allowing one to correlate single-cell activity with motor behavior to the extent of determining the role of single neuronal types and single connection pathways in controlling precise aspects of movement kinematics. These levels of specificity in correlating neuronal activity to behavior could not be achieved in the past, when electrical and pharmacological stimulations were the only available experimental tools. The application of optogenetics to the investigation of the cerebellar role in higher-order and cognitive functions, which involves a high degree of connectivity with multiple brain areas, has been even more significant. It is possible that, in this field, optogenetics has changed the game, and the number of investigations using optogenetics to study the cerebellar role in non-sensorimotor functions in awake animals is growing. The main issues addressed by these studies are the cerebellar role in epilepsy (through connections to the hippocampus and the temporal lobe), schizophrenia and cognition, working memory for decision making, and social behavior. It is also worth noting that optogenetics opened a new perspective for cerebellar neurostimulation in patients (e.g., for epilepsy treatment and stroke rehabilitation), promising unprecedented specificity in the targeted pathways that could be either activated or inhibited.
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