1
|
Chen F, Dong X, Wang Z, Wu T, Wei L, Li Y, Zhang K, Ma Z, Tian C, Li J, Zhao J, Zhang W, Liu A, Shen H. Regulation of specific abnormal calcium signals in the hippocampal CA1 and primary cortex M1 alleviates the progression of temporal lobe epilepsy. Neural Regen Res 2024; 19:425-433. [PMID: 37488907 PMCID: PMC10503629 DOI: 10.4103/1673-5374.379048] [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: 02/06/2023] [Revised: 03/15/2023] [Accepted: 05/04/2023] [Indexed: 07/26/2023] Open
Abstract
Temporal lobe epilepsy is a multifactorial neurological dysfunction syndrome that is refractory, resistant to antiepileptic drugs, and has a high recurrence rate. The pathogenesis of temporal lobe epilepsy is complex and is not fully understood. Intracellular calcium dynamics have been implicated in temporal lobe epilepsy. However, the effect of fluctuating calcium activity in CA1 pyramidal neurons on temporal lobe epilepsy is unknown, and no longitudinal studies have investigated calcium activity in pyramidal neurons in the hippocampal CA1 and primary motor cortex M1 of freely moving mice. In this study, we used a multi-channel fiber photometry system to continuously record calcium signals in CA1 and M1 during the temporal lobe epilepsy process. We found that calcium signals varied according to the grade of temporal lobe epilepsy episodes. In particular, cortical spreading depression, which has recently been frequently used to represent the continuously and substantially increased calcium signals, was found to correspond to complex and severe behavioral characteristics of temporal lobe epilepsy ranging from grade II to grade V. However, vigorous calcium oscillations and highly synchronized calcium signals in CA1 and M1 were strongly related to convulsive motor seizures. Chemogenetic inhibition of pyramidal neurons in CA1 significantly attenuated the amplitudes of the calcium signals corresponding to grade I episodes. In addition, the latency of cortical spreading depression was prolonged, and the above-mentioned abnormal calcium signals in CA1 and M1 were also significantly reduced. Intriguingly, it was possible to rescue the altered intracellular calcium dynamics. Via simultaneous analysis of calcium signals and epileptic behaviors, we found that the progression of temporal lobe epilepsy was alleviated when specific calcium signals were reduced, and that the end-point behaviors of temporal lobe epilepsy were improved. Our results indicate that the calcium dynamic between CA1 and M1 may reflect specific epileptic behaviors corresponding to different grades. Furthermore, the selective regulation of abnormal calcium signals in CA1 pyramidal neurons appears to effectively alleviate temporal lobe epilepsy, thereby providing a potential molecular mechanism for a new temporal lobe epilepsy diagnosis and treatment strategy.
Collapse
Affiliation(s)
- Feng Chen
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
- Institute for Translational Neuroscience, the Second Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xi Dong
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
- Institute for Translational Brain Research, Fudan University, Shanghai, China
| | - Zhenhuan Wang
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Tongrui Wu
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Liangpeng Wei
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
- Department of Radiology, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
| | - Yuanyuan Li
- Innovative Institute of Chinese Medicine and Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Kai Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Zengguang Ma
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Chao Tian
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Jing Li
- Department of Orthopaedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Jingyu Zhao
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Wei Zhang
- Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin, China
| | - Aili Liu
- Laboratory of Neurobiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Hui Shen
- Innovative Institute of Chinese Medicine and Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, China
- Laboratory of Neurobiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| |
Collapse
|
2
|
Hyder SK, Ghosh A, Forcelli PA. Optogenetic activation of the superior colliculus attenuates spontaneous seizures in the pilocarpine model of temporal lobe epilepsy. Epilepsia 2023; 64:524-535. [PMID: 36448878 PMCID: PMC10907897 DOI: 10.1111/epi.17469] [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: 09/03/2022] [Revised: 11/04/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022]
Abstract
OBJECTIVE Decades of studies have indicated that activation of the deep and intermediate layers of the superior colliculus can suppress seizures in a wide range of experimental models of epilepsy. However, prior studies have not examined efficacy against spontaneous limbic seizures. The present study aimed to address this gap through chronic optogenetic activation of the superior colliculus in the pilocarpine model of temporal lobe epilepsy. METHODS Sprague Dawley rats underwent pilocarpine-induced status epilepticus and were maintained until the onset of spontaneous seizures. Virus coding for channelrhodopsin-2 was injected into the deep and intermediate layers of the superior colliculus, and animals were implanted with head-mounted light-emitting diodes at the same site. Rats were stimulated with either 5- or 100-Hz light delivery. Seizure number, seizure duration, 24-h seizure burden, and behavioral seizure severity were monitored. RESULTS Both 5- and 100-Hz optogenetic stimulation of the deep and intermediate layers of the superior colliculus reduced daily seizure number and total seizure burden in all animals in the active vector group. Stimulation did not affect either seizure duration or behavioral seizure severity. Stimulation was without effect in opsin-negative control animals. SIGNIFICANCE Activation of the deep and intermediate layers of the superior colliculus reduces both the number of seizures and total daily seizure burden in the pilocarpine model of temporal lobe epilepsy. These novel data demonstrating an effect against chronic experimental seizures complement a long history of studies documenting the antiseizure efficacy of superior colliculus activation in a range of acute seizure models.
Collapse
Affiliation(s)
- Safwan K. Hyder
- Department of Pharmacology & Physiology, Georgetown University, Washington DC, USA
| | - Anjik Ghosh
- Department of Pharmacology & Physiology, Georgetown University, Washington DC, USA
| | - Patrick A. Forcelli
- Department of Pharmacology & Physiology, Georgetown University, Washington DC, USA
- Department of Neuroscience, Georgetown University, Washington DC, USA
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington DC, USA
| |
Collapse
|
3
|
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
|
4
|
Abstract
PURPOSE OF REVIEW Depression and anxiety substantially contribute to interictal disability in patients with epilepsy (PWE). This review summarizes current studies that shed light on mechanisms of comorbidity. RECENT FINDINGS Mounting epidemiological data implicate shared risk factors for anxiety/depression and seizure propensity, but these remain largely elusive and probably vary by epilepsy type. Within PWE, these symptoms appear to be associated with unique genetic, neuropathological, and connectivity profiles. Temporal lobe epilepsy has received enormous emphasis particularly in preclinical studies of comorbidity, where candidate neurobiological mechanisms underlying bidirectionality have been tested without psychopharmacological confounds. Depression and anxiety in epilepsy reflect dysfunction within broadly distributed limbic networks that may be the cause or consequence of epileptogenesis. In refractory epilepsy, seizures and/or certain anticonvulsants may distort central emotional homeostatic mechanisms that perpetually raise seizure risk. Developing future safe and effective combined anticonvulsant-antidepressant treatments will require a detailed understanding of anatomical and molecular nodes that pleiotropically enhance seizure risk and negatively alter emotionality.
Collapse
Affiliation(s)
- Vaishnav Krishnan
- Departments of Neurology, Neuroscience and Psychiatry & Behavioral Sciences, Baylor Comprehensive Epilepsy Center, Baylor College of Medicine, One Baylor Plaza St., MS: NB302, Houston, TX, 77030, USA.
| |
Collapse
|
5
|
Skopin MD, Bayat A, Kurada L, Siddu M, Joshi S, Zelano CM, Koubeissi MZ. Epileptogenesis-induced changes of hippocampal-piriform connectivity. Seizure 2020; 81:1-7. [PMID: 32682283 DOI: 10.1016/j.seizure.2020.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 07/06/2020] [Accepted: 07/09/2020] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Tissue remodeling has been described in brain circuits that are involved in the generation and propagation of epileptic seizures. Human and animal studies suggest that the anterior piriform cortex (aPC) is crucial for seizure expression in focal epilepsies. Here, we investigate the effect of kainic-acid (KA)-induced seizures on the effective connectivity of the aPC with bilateral hippocampal CA3 regions using cerebro-cerebral evoked potentials (CCEPs). METHODS Adult male Sprague-Dawley rats were implanted with a tripolar electrode in the left aPC for stimulation and recording, and with unipolar recording electrodes in bilateral CA3 regions. Single pulse stimulations were given to the aPC and CCEPs were averaged before KA injections and after the emergence of spontaneous recurrent seizures (SRS). Similar recordings at equivalent time intervals were obtained from animals that received saline injections instead of KA (controls). RESULTS In the experimental group, the percentage change of increased amplitude of the contralateral (but not ipsilateral) CA3 CCEPs between pre-KA injection and after the emergence of SRS was significantly greater than in controls. No significant single-pulse-induced spectral change responses were observed in either epileptic or control rats when comparing pre- and post-stimulus time intervals. Also, we found no correlation between seizure frequency and the extent of amplitude changes in the CCEPs. CONCLUSIONS In the KA model, epileptogenesis results in plastic changes that manifest as an amplification of evoked potential amplitudes recorded in the contralateral hippocampus in response to single-pulse stimulation of the aPC. These results suggest epileptogenesis-induced facilitation of interhemispheric connectivity between the aPC and the hippocampus. Since the amplitude increase of the contralateral CCEP is a possible in vivo biomarker of epilepsy, any intervention (e.g. neuromodulatory) that can reverse this phenomenon may hold a potential antiepileptic efficacy.
Collapse
Affiliation(s)
- Mark D Skopin
- Department of Neurology, George Washington University, Washington, DC, 20037, USA
| | - Arezou Bayat
- Department of Neurology, George Washington University, Washington, DC, 20037, USA
| | - Lalitha Kurada
- Department of Neurology, George Washington University, Washington, DC, 20037, USA
| | - Mithilesh Siddu
- Department of Neurology, George Washington University, Washington, DC, 20037, USA
| | - Sweta Joshi
- Department of Neurology, George Washington University, Washington, DC, 20037, USA
| | - Christina M Zelano
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Mohamad Z Koubeissi
- Department of Neurology, George Washington University, Washington, DC, 20037, USA.
| |
Collapse
|
6
|
Dong X, Zhang X, Wang F, Liu N, Liu A, Li Y, Wei L, Chen F, Yuan S, Zhang K, Hou S, Jiao Q, Hu Q, Guo C, Wu T, Wei S, Shen H. Simultaneous calcium recordings of hippocampal CA1 and primary motor cortex M1 and their relations to behavioral activities in freely moving epileptic mice. Exp Brain Res 2020; 238:1479-1488. [PMID: 32424694 DOI: 10.1007/s00221-020-05815-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 04/15/2020] [Indexed: 11/25/2022]
Abstract
Epilepsy is a common neurological disorder characterized by recurrent epileptic seizures. The cause of most cases of epilepsy is unknown. Although changes of calcium events in a single brain region during seizures have been reported before, there have been few studies on relations between calcium events of two different brain regions and epileptic behaviors in freely moving mice. To analyze calcium events simultaneously recorded in hippocampal CA1 (CA1) and primary motor cortex M1 (M1), and to explore their relations to various epileptic behaviors in freely moving epileptic models. Epileptic models were induced by Kainic acid (KA), a direct agonist of glutamatergic receptor, on adult male C57/BL6J mice. Calcium events of neurons and glia in CA1 and M1 labeled by a calcium indicator dye were recorded simultaneously with a multi-channel fiber photometry system. Three typical types of calcium events associated with KA-induced seizures were observed, including calcium baseline-rising, cortical spreading depression (CSD) and calcium flashing with a steady rate. Our results showed that the calcium baseline-rising occurred in CA1 was synchronized with that in M1, but the CSD waves were not. However, synchronization of calcium flashing in the two areas was uncertain, because it was only detected in CA1. We also observed that different calcium events happened with different epileptic behaviors. Baseline-rising events were accompanied by clonus of forelimbs or trembling, CSD waves were closely related to head movements (15 out of 18, 6 mice). Calcium flashing occurred definitely with drastic convulsive motor seizures (CMS, 6 mice). The results prove that the synchronization of calcium event exists in CA1 and M1, and different calcium events are related with different seizure behaviors. Our results suggest that calcium events involve in the synchronization of neural network and behaviors in epilepsy.
Collapse
Affiliation(s)
- Xi Dong
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Xin Zhang
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Feifei Wang
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Nannan Liu
- Tianjin Mental Health Institute, Tianjin Anding Hospital, Tianjin, China
| | - Aili Liu
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Yuanyuan Li
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Liangpeng Wei
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Feng Chen
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Shiyang Yuan
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China
| | - Kai Zhang
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China
| | - Shaowei Hou
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Qingyan Jiao
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Qi Hu
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Cunle Guo
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Tongrui Wu
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Sheng Wei
- Experimental Center, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Hui Shen
- Laboratory of Neurobiology, School of Biomedical Engineering, Tianjin Medical University, Tianjin, China. .,Institute of Neurology, Tianjin Medical University General Hospital, Tianjin, China.
| |
Collapse
|
7
|
Giorgi FS, Galgani A, Gaglione A, Ferese R, Fornai F. Effects of Prolonged Seizures on Basal Forebrain Cholinergic Neurons: Evidence and Potential Clinical Relevance. Neurotox Res 2020; 38:249-265. [PMID: 32319018 DOI: 10.1007/s12640-020-00198-w] [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: 02/05/2020] [Revised: 03/11/2020] [Accepted: 03/16/2020] [Indexed: 10/24/2022]
Abstract
Seizures originating from limbic structures, especially when prolonged for several minutes/hours up to status epilepticus (SE), can cause specific neurodegenerative phenomena in limbic and subcortical structures. The cholinergic nuclei belonging to the basal forebrain (BF) (namely, medial septal nucleus (MSN), diagonal band of Broca (DBB), and nucleus basalis of Meynert (NBM)) belong to the limbic system, while playing a pivotal role in cognition and sleep-waking cycle. Given the strong interconnections linking these limbic nuclei with limbic cortical structures, a persistent effect of SE originating from limbic structures on cBF morphology is plausible. Nonetheless, only a few experimental studies have addressed this issue. In this review, we describe available data and discuss their significance in the scenario of seizure-induced brain damage. In detail, the manuscript moves from a recent study in a model of focally induced limbic SE, in which the pure effects of seizure spreading through the natural anatomical pathways towards the cholinergic nuclei of BF were tracked by neuronal degeneration. In this experimental setting, a loss of cholinergic neurons was measured in all BF nuclei, to various extents depending on the specific nucleus. These findings are discussed in the light of the effects on the very same nuclei following SE induced by systemic injections of kainate or pilocarpine. The various effects including discrepancies among different studies are discussed. Potential implications for human diseases are included.
Collapse
Affiliation(s)
- Filippo Sean Giorgi
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.
| | - Alessandro Galgani
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | | | - Francesco Fornai
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.,IRCCS INM Neuromed, Pozzilli, Italy
| |
Collapse
|
8
|
Joshi S, Bayat A, Jones A, Xiao X, Koubeissi MZ. The effects of ammonia stimulation on kainate-induced status epilepticus and anterior piriform cortex electrophysiology. Epilepsy Behav 2020; 104:106885. [PMID: 31935647 DOI: 10.1016/j.yebeh.2019.106885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/19/2019] [Accepted: 12/19/2019] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Strong olfactory stimulation (OS) with such substances as toluene or ammonia has been reported to suppress seizures. We aimed to investigate the role of ammonia stimulation on acute kainic acid (KA)-induced seizures. We also investigated any possible effects of ammonia stimulation on the electrophysiology of the anterior piriform cortex (APC). METHODS Adult male Sprague-Dawley rats were implanted with bilateral hippocampal electrodes and an electrode in the left APC. Animals were exposed to either distilled water (control) or ammonia stimulation for 20 s every 5 min during KA induction of status epilepticus (SE). The electroencephalogram (EEG) was analyzed for seizure frequency, duration, severity, and total KA doses given prior to reaching SE. Seizure-free EEG epochs that coincided with OS were chosen and analyzed via wavelet analysis for any spectral changes. RESULTS We found no significant differences in seizure frequency, duration, severity, or administered KA doses before SE between the groups. In the experimental group, a wavelet analysis of variance (WANOVA) revealed a significant stimulation-induced increase of power in the delta and alpha bands prior to the first KA injection and higher power in the delta and theta bands after KA injection. CONCLUSIONS Whereas the spectral analysis of the APC revealed specific OS-induced changes, our findings suggest that OS with ammonia does not result in altering the threshold of attaining KA-induced SE. This does not rule out a potential role for OS in reducing recurrent seizures in the KA or other epilepsy models.
Collapse
Affiliation(s)
- Sweta Joshi
- Department of Neurology, George Washington University, 2150 Pennsylvania Ave, NW, Washington, DC 20037, USA
| | - Arezou Bayat
- Department of Neurology, George Washington University, 2150 Pennsylvania Ave, NW, Washington, DC 20037, USA
| | - Andrew Jones
- Translational Health Sciences, George Washington University, 2100 Pennsylvania Ave, NW, Washington, DC 20037, USA
| | - Xiao Xiao
- School of Engineering and Applied Science, George Washington University, 800 22nd St NW, Washington, DC 20052, USA
| | - Mohamad Z Koubeissi
- Department of Neurology, George Washington University, 2150 Pennsylvania Ave, NW, Washington, DC 20037, USA.
| |
Collapse
|
9
|
Kurada L, Bayat A, Joshi S, Chahine A, Koubeissi MZ. Antiepileptic effects of electrical stimulation of the piriform cortex. Exp Neurol 2020; 325:113070. [DOI: 10.1016/j.expneurol.2019.113070] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 09/17/2019] [Accepted: 09/24/2019] [Indexed: 12/26/2022]
|
10
|
Jain S, LaFrancois JJ, Botterill JJ, Alcantara-Gonzalez D, Scharfman HE. Adult neurogenesis in the mouse dentate gyrus protects the hippocampus from neuronal injury following severe seizures. Hippocampus 2019; 29:683-709. [PMID: 30672046 PMCID: PMC6640126 DOI: 10.1002/hipo.23062] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/29/2018] [Accepted: 11/30/2018] [Indexed: 01/20/2023]
Abstract
Previous studies suggest that reducing the numbers of adult-born neurons in the dentate gyrus (DG) of the mouse increases susceptibility to severe continuous seizures (status epilepticus; SE) evoked by systemic injection of the convulsant kainic acid (KA). However, it was not clear if the results would be the same for other ways to induce seizures, or if SE-induced damage would be affected. Therefore, we used pilocarpine, which induces seizures by a different mechanism than KA. Also, we quantified hippocampal damage after SE. In addition, we used both loss-of-function and gain-of-function methods in adult mice. We hypothesized that after loss-of-function, mice would be more susceptible to pilocarpine-induced SE and SE-associated hippocampal damage, and after gain-of-function, mice would be more protected from SE and hippocampal damage after SE. For loss-of-function, adult neurogenesis was suppressed by pharmacogenetic deletion of dividing radial glial precursors. For gain-of-function, adult neurogenesis was increased by conditional deletion of pro-apoptotic gene Bax in Nestin-expressing progenitors. Fluoro-Jade C (FJ-C) was used to quantify neuronal injury and video-electroencephalography (video-EEG) was used to quantify SE. Pilocarpine-induced SE was longer in mice with reduced adult neurogenesis, SE had more power and neuronal damage was greater. Conversely, mice with increased adult-born neurons had shorter SE, SE had less power, and there was less neuronal damage. The results suggest that adult-born neurons exert protective effects against SE and SE-induced neuronal injury.
Collapse
Affiliation(s)
- Swati Jain
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
| | - John J. LaFrancois
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
| | - Justin J. Botterill
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
| | - David Alcantara-Gonzalez
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
| | - Helen E. Scharfman
- Center for Dementia Research, The Nathan Kline Institute of Psychiatric Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA
- Departments of Child & Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, New York Langone Medical Center, New York, NY 10016, USA
| |
Collapse
|
11
|
Stereotypical patterns of epileptiform calcium signal in hippocampal CA1, CA3, dentate gyrus and entorhinal cortex in freely moving mice. Sci Rep 2019; 9:4518. [PMID: 30872744 PMCID: PMC6418290 DOI: 10.1038/s41598-019-41241-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 03/04/2019] [Indexed: 11/08/2022] Open
Abstract
Epilepsy is a multi-etiological brain dysfunction syndrome. Hippocampal neuronal damage induced by seizures may be one of the causes leading to cognitive impairment, but the underlying mechanism remains to be further elucidated. The kainic acid (KA) model of temporal lobe epilepsy is widely used in understanding of the epileptogenesis. Fiber photometry is a signal detection technology suitable for recording calcium activity of neurons in the deep brain of freely moving animal. Here, we used the optical fiber-based method to monitor the real-time neuronal population activities of freely moving mice after subcutaneous injection of KA. We observed that KA administration led to one to three kinds of stereotypical patterns of epileptiform calcium activity in CA1, CA3, and dentate gyrus (DG) of the hippocampus, as well as the entorhinal cortex (EC). There were three kinds of waves in the hippocampal CA1, which we named wave 1, wave 2 and slow flash. Wave 1 and wave 2 appeared in both the CA3 and DG regions, but the EC only showed wave 1. In these epileptiform calcium signals, we observed a high amplitude and long duration calcium wave as a part of wave 2, which resembled cortical spreading depression (CSD) and always appeared at or after the end of seizure. Because the same characteristic of epileptiform calcium signal appeared in different brain regions, calcium signal may not exist with region specificity, but may exhibit a cell type specific manner. Thus, our work provides a support for the pathogenesis of epilepsy and epileptiform signal transmission research.
Collapse
|
12
|
Kurada L, Bayat A, Joshi S, Koubeissi MZ. The Claustrum in Relation to Seizures and Electrical Stimulation. Front Neuroanat 2019; 13:8. [PMID: 30809132 PMCID: PMC6379271 DOI: 10.3389/fnana.2019.00008] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 01/21/2019] [Indexed: 12/12/2022] Open
Abstract
The neural mechanisms of altered consciousness that accompanies most epileptic seizures are not known. We have reported alteration of consciousness resulting from electrical stimulation of the claustrum via a depth electrode in a woman with refractory focal epilepsy. Additionally, there are reports that suggest possible claustral involvement in focal epilepsy, including MRI findings of bilaterally increased T2 signal intensity in patients with status epilepticus (SE). Although its cytoarchitecture and connectivity have been studied extensively, the precise role of the claustrum in consciousness processing, and, thus, its contribution to the semiology of dyscognitive seizures are still elusive. To investigate the role of the claustrum in rats, we studied the effect of high-frequency stimulation (HFS) of the claustrum on performance in the operant chamber. We also studied the inter-claustral and the claustro-hippocampal connectivity through cerebro-cerebral evoked potentials (CCEPs), and investigated the involvement of the claustrum in kainate (KA)-induced seizures. We found that HFS of the claustrum decreased the performance in the operant task in a manner that was proportional to the current intensity used. In this article, we present previously unpublished data about the effect of stimulating extra-claustral regions in the operant chamber task as a control experiment. In these animals, stimulation of the corpus callosum, the largest interhemispheric commissure, as well as the orbitofrontal cortex in the vicinity of the claustrum did not produce that same effect as with claustral stimulation. Additionally, CCEPs established the presence of effective connectivity between both claustra, as well as between the claustrum and bilateral hippocampi indicating that these connections may be part of the circuitry involved in alteration of consciousness in limbic seizures. Lastly, some seizures induced by KA injections showed an early involvement of the claustrum with later propagation to the hippocampi. Further work is needed to clarify the exact role of the claustrum in mediating alteration of consciousness during epileptic seizures.
Collapse
Affiliation(s)
- Lalitha Kurada
- Department of Neurology, The George Washington University, Washington, DC, United States
| | - Arezou Bayat
- Department of Neurology, The George Washington University, Washington, DC, United States
| | - Sweta Joshi
- Department of Neurology, The George Washington University, Washington, DC, United States
| | - Mohamad Z Koubeissi
- Department of Neurology, The George Washington University, Washington, DC, United States
| |
Collapse
|
13
|
A pilot study of the role of the claustrum in attention and seizures in rats. Epilepsy Res 2018; 140:97-104. [PMID: 29324357 DOI: 10.1016/j.eplepsyres.2018.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/07/2017] [Accepted: 01/03/2018] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The claustrum has been implicated in consciousness, and MRIs of patients with status epilepticus have shown increased claustral signal intensity. In an attempt to investigate the role of claustrum in cognition and seizures, we (1) assessed the effect of high-frequency stimulation (HFS) of the claustrum on performance in the operant chamber; (2) studied interclaustral and claustrohippocampal connectivity through cerebro-cerebral evoked potentials (CCEPs); and (3) investigated the role of claustrum in kainate-induced (KA) seizures. METHODS Adult male Sprague-Dawley rats were trained in operant conditioning and implanted with electrodes in bilateral claustra and hippocampi. Claustrum HFS (50 Hz) was delivered bilaterally and unilaterally with increasing intensities from 50 to 1000 μA, and performance scores were assessed. CCEPs were studied by averaging the responses to bipolar stimulations, 1-ms wide pulses at 0.1 Hz to the claustrum. KA seizures were analyzed on video-EEG recordings. RESULTS Generalized Estimating Equations analysis revealed that claustral stimulation reduced task performance scores relative to rest sessions (bilateral: -15.8 percentage points, p < 0.0001; unilateral: -15.2, p < 0.0001). With some stimulations, the rats showed a stimulus-locked decrease in attentiveness and, occasionally, an inability to complete the operant task. CCEPs demonstrated interclaustral and claustrohippocampal connectivity. Some KA seizures appeared to originate from the claustrum. CONCLUSIONS Findings from the operant conditioning task suggest stimulation of the claustrum can alter attention or awareness. CCEPs demonstrated connectivity between the two claustra and between the claustrum and the hippocampi. Such connectivity may be part of the circuitry that underlies the alteration of awareness in limbic seizures. Lastly, KA seizures showed early involvement of the claustrum, a finding that also supports a possible role of the claustrum in the alteration of consciousness that accompanies dyscognitive seizures.
Collapse
|
14
|
Effects of low-frequency electrical stimulation of the anterior piriform cortex on kainate-induced seizures in rats. Epilepsy Behav 2017; 72:1-7. [PMID: 28564587 DOI: 10.1016/j.yebeh.2017.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/15/2017] [Accepted: 04/03/2017] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Recent evidence in animals and humans suggests that low-frequency stimulation (LFS) has significant antiepileptic properties. The anterior piriform cortex (APC) is a highly susceptible seizure-trigger zone and may be critical for the initiation and propagation of seizures originating from cortical and limbic foci. We used the kainic acid (KA) seizure model in rats to assess the therapeutic effect of LFS of the APC on seizures. METHODS Adult male Sprague-Dawley rats were implanted with electrodes in the left APC and recording electrodes bilaterally in the hippocampal CA3 regions. Rats were monitored continuously with video-EEG after the emergence of spontaneous recurrent seizures that followed induction of status epilepticus by intraperitoneal KA. After two weeks of baseline recordings to determine seizure frequency, LFS of the APC was applied 60-min On 15-min Off, for two weeks with 1Hz biphasic square waves, 0.2ms pulse width, at 200μA. Another 2-week period of video-EEG monitoring was done after the cessation of LFS to study the carry-over effect. Changes in seizure frequency, severity, and duration between baseline, during LFS, and post-LFS were analyzed using the Poisson regression model. RESULTS Overall seizure frequency decreased during the post-LFS period to 5% of that at baseline (p=0.003). Severe seizures (stages 4 and 5 on the Racine scale) decreased to 0% of the baseline during the post-LFS period. CONCLUSIONS Two weeks of LFS of the APC reduced spontaneous seizure frequency and severity in the KA model with the effect outlasting the stimulation. Our findings suggest that the APC can be an important therapeutic target for stimulation in epilepsy.
Collapse
|