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Caron D, Canal-Alonso Á, Panuccio G. Mimicking CA3 Temporal Dynamics Controls Limbic Ictogenesis. BIOLOGY 2022; 11:371. [PMID: 35336745 PMCID: PMC8944954 DOI: 10.3390/biology11030371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common partial complex epilepsy in adults and the most unresponsive to medications. Electrical deep brain stimulation (DBS) of the hippocampus has proved effective in controlling seizures in epileptic rodents and in drug-refractory MTLE patients. However, current DBS paradigms implement arbitrary fixed-frequency or patterned stimuli, disregarding the temporal profile of brain electrical activity. The latter, herein included hippocampal spontaneous firing, has been shown to follow lognormal temporal dynamics. Here, we present a novel paradigm to devise DBS protocols based on stimulation patterns fashioned as a surrogate brain signal. We focus on the interictal activity originating in the hippocampal subfield CA3, which has been shown to be anti-ictogenic. Using 4-aminopyridine-treated hippocampus-cortex slices coupled to microelectrode array, we pursue three specific aims: (1) address whether lognormal temporal dynamics can describe the CA3-driven interictal pattern, (2) explore the possibility of restoring the non-seizing state by mimicking the temporal dynamics of this anti-ictogenic pattern with electrical stimulation, and (3) compare the performance of the CA3-surrogate against periodic stimulation. We show that the CA3-driven interictal activity follows lognormal temporal dynamics. Further, electrical stimulation fashioned as a surrogate interictal pattern exhibits similar efficacy but uses less pulses than periodic stimulation. Our results support the possibility of mimicking the temporal dynamics of relevant brain signals as a straightforward DBS strategy to ameliorate drug-refractory epilepsy. Further, they herald a paradigm shift in neuromodulation, wherein a compromised brain signal can be recreated by the appropriate stimuli distribution to bypass trial-and-error studies and attain physiologically meaningful DBS operating modes.
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Affiliation(s)
- Davide Caron
- Enhanced Regenerative Medicine, Istituto Italiano di Tecnologia, 16163 Genova, Italy;
| | - Ángel Canal-Alonso
- BISITE Research Group, University of Salamanca, 37008 Salamanca, Spain;
- Institute for Biomedical Research of Salamanca, University of Salamanca, 37008 Salamanca, Spain
| | - Gabriella Panuccio
- Enhanced Regenerative Medicine, Istituto Italiano di Tecnologia, 16163 Genova, Italy;
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Mihály I, Molnár T, Berki ÁJ, Bod RB, Orbán-Kis K, Gáll Z, Szilágyi T. Short-Term Amygdala Low-Frequency Stimulation Does not Influence Hippocampal Interneuron Changes Observed in the Pilocarpine Model of Epilepsy. Cells 2021; 10:cells10030520. [PMID: 33804543 PMCID: PMC7998440 DOI: 10.3390/cells10030520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/19/2021] [Accepted: 02/25/2021] [Indexed: 11/23/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is characterized by changes in interneuron numbers in the hippocampus. Deep brain stimulation (DBS) is an emerging tool to treat TLE seizures, although its mechanisms are not fully deciphered. We aimed to depict the effect of amygdala DBS on the density of the most common interneuron types in the CA1 hippocampal subfield in the lithium-pilocarpine model of epilepsy. Status epilepticus was induced in male Wistar rats. Eight weeks later, a stimulation electrode was implanted to the left basolateral amygdala of both pilocarpine-treated (Pilo, n = 14) and age-matched control rats (n = 12). Ten Pilo and 4 control animals received for 10 days 4 daily packages of 50 s 4 Hz regular stimulation trains. At the end of the stimulation period, interneurons were identified by immunolabeling for parvalbumin (PV), neuropeptide Y (NPY), and neuronal nitric oxide synthase (nNOS). Cell density was determined in the CA1 subfield of the hippocampus using confocal microscopy. We found that PV+ cell density was preserved in pilocarpine-treated rats, while the NPY+/nNOS+ cell density decreased significantly. The amygdala DBS did not significantly change the cell density in healthy or in epileptic animals. We conclude that DBS with low frequency applied for 10 days does not influence interneuron cell density changes in the hippocampus of epileptic rats.
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Affiliation(s)
- István Mihály
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (T.M.); (Á.-J.B.); (R.-B.B.); (K.O.-K.); (T.S.)
- Correspondence: ; Tel.: +40-749-768-257
| | - Tímea Molnár
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (T.M.); (Á.-J.B.); (R.-B.B.); (K.O.-K.); (T.S.)
| | - Ádám-József Berki
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (T.M.); (Á.-J.B.); (R.-B.B.); (K.O.-K.); (T.S.)
| | - Réka-Barbara Bod
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (T.M.); (Á.-J.B.); (R.-B.B.); (K.O.-K.); (T.S.)
| | - Károly Orbán-Kis
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (T.M.); (Á.-J.B.); (R.-B.B.); (K.O.-K.); (T.S.)
| | - Zsolt Gáll
- Department of Pharmacology and Clinical Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania;
| | - Tibor Szilágyi
- Department of Physiology, Faculty of Medicine, George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (T.M.); (Á.-J.B.); (R.-B.B.); (K.O.-K.); (T.S.)
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Wang L, Shi H, Kang Y, Guofeng W. Hippocampal low-frequency stimulation improves cognitive function in pharmacoresistant epileptic rats. Epilepsy Res 2019; 168:106194. [PMID: 31521425 DOI: 10.1016/j.eplepsyres.2019.106194] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 08/05/2019] [Accepted: 08/28/2019] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The aims of the present study were to observe the changes of cognitive function in a pilocarpine-induced rat model of epilepsy, and to investigate the effects of hippocampal low-frequency stimulation (Hip-LFS) on cognitive function in rats with pharmacoresistant epilepsy. METHODS A total of 100 male Sprague Dawley rats were randomly selected to establish an epilepsy model. Rats with successfully induced epilepsy were injected intraperitoneally with phenobarbital and phenytoin for pharmacoresistance selection. The selected pharmacoresistant epileptic (PRE) rats were assigned to a pharmacoresistant control group (PRC group), or a group that received Hip-LFS (LFS group). The same number of rats with pharmacosensitive epilepsy formed the PSC group, and a normal control (NCR) group was included. A novel object recognition (NOR) test, and a Morris water maze (MWM) task were used to assess cognitive function in all groups. RESULTS The epileptic rats showed decreased abilities of learning and memory compared with normal control. The rats in the LFS group displayed significantly shorter escape latency in place navigation, spent longer times in the target quadrant, and traveled longer distances on the platform in the spatial probe test than PRC group. In the NOR test, compared with the PRC group, the discrimination index of the LFS group was significantly increased. Compared with the PRC group, the average frequency and duration of seizures were also decreased in the LFS group. CONCLUSIONS The present pilocarpine-induced rat model of epilepsy showed impaired cognitive function, especially in rats with PRE. The Hip-LFS treatment could effectively improve the cognitive function of rats with PRE.
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Affiliation(s)
- Likun Wang
- Emergency Department, Affiliated Hospital of Guizhou Medical University, Guiyang City, 550004, PR China.
| | - Haiyan Shi
- Emergency Department, Affiliated Hospital of Guizhou Medical University, Guiyang City, 550004, PR China.
| | - Yangting Kang
- Emergency Department, Affiliated Hospital of Guizhou Medical University, Guiyang City, 550004, PR China.
| | - Wu Guofeng
- Emergency Department, Affiliated Hospital of Guizhou Medical University, Guiyang City, 550004, PR China.
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Wang Y, Chen Z. An update for epilepsy research and antiepileptic drug development: Toward precise circuit therapy. Pharmacol Ther 2019; 201:77-93. [PMID: 31128154 DOI: 10.1016/j.pharmthera.2019.05.010] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 12/14/2022]
Abstract
Epilepsy involves neuronal dysfunction at molecular, cellular, and circuit levels. The understanding of the mechanism of the epilepsies has advanced greatly in the last three decades, especially in terms of their cellular and molecular basis. However, despite the availability of ~30 anti-epileptic drugs (AEDs) with diverse molecular targets, there are still many challenges (e.g. drug resistance, side effects) in pharmacological treatment of epilepsies today. Because molecular mechanisms are integrated at the level of neuronal circuits, we suggest a shift in epilepsy treatment and research strategies from the "molecular" level to the "circuit" level. Recent technological advances have facilitated circuit mechanistic discovery at each level and have paved the way for many opportunities of novel therapeutic strategies and AED development toward precise circuit therapy.
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Affiliation(s)
- Yi Wang
- Institute of Pharmacology and Toxicology, Department of Pharmacology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhong Chen
- Institute of Pharmacology and Toxicology, Department of Pharmacology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China; Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.
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Zheng Y, Jiang Z, Ping A, Zhang F, Zhu J, Wang Y, Zhu W, Xu K. Acute Seizure Control Efficacy of Multi-Site Closed-Loop Stimulation in a Temporal Lobe Seizure Model. IEEE Trans Neural Syst Rehabil Eng 2019; 27:419-428. [DOI: 10.1109/tnsre.2019.2894746] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Xu K, Liu Z, Wang L, Wu G, Liu T. Influence of hippocampal low-frequency stimulation on GABA A R α1, ICER and BNDF expression level in brain tissues of amygdala-kindled drug-resistant temporal lobe epileptic rats. Brain Res 2018; 1698:195-203. [PMID: 30118718 DOI: 10.1016/j.brainres.2018.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 08/07/2018] [Accepted: 08/08/2018] [Indexed: 02/06/2023]
Abstract
This study investigated the therapeutic effect of hippocampal low-frequency stimulation (Hip-LFS) and its influence on the type A γ-aminobutyric acid receptor α1 subunit (GABAA R α1 subunit), inducible cAMP early repressor (ICER) and brain-derived neurotrophic factors (BNDF). The model of epilepsy was induced by chronic electrical stimulation in amygdala. Drug-resistant and drug-sensitive epileptic rats were selected by testing their seizure response to phenytoin and phenobarbital. The changes of GABAA R α1 subunit, ICER and BDNF expression were detected via immunohistochemistry and western blot. The expression levels of ICER and BDNF were increased remarkably but the GABAA R α1 subunit decreased significantly in the drug-resistant epileptic rats. However, the expression levels of ICER, BDNF were decreased and the expression of the GABAA R α1 subunit increased significantly in the drug-resistant epileptic rats after two weeks of Hip-LFS. Meanwhile, the seizure degree was reduced and the electroencephalograms were improved. The present study demonstrated thatincreased ICER and BDNF might be associated with the development of drug-resistance. The effect of Hip-LFS in the treatment of drug-resistant epileptic rats might be associated with increasing the levels of the ICER and the BDNF.
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Affiliation(s)
- Kaya Xu
- Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, PR China
| | - Zhaoyang Liu
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, PR China
| | - Likun Wang
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, PR China
| | - Guofeng Wu
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guizhou, Guiyang City, PR China.
| | - Tao Liu
- Guizhou Province Centre of Disease Control and Prevention, Guiyang City, PR China.
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Bartoli A, Tyrand R, Vargas MI, Momjian S, Boëx C. Low Frequency Microstimulation Is Locally Excitatory in Patients With Epilepsy. Front Neural Circuits 2018; 12:22. [PMID: 29670511 PMCID: PMC5893788 DOI: 10.3389/fncir.2018.00022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 02/26/2018] [Indexed: 11/13/2022] Open
Abstract
Deep brain stimulation (DBS) could become a palliative treatment for patients with drug-resistant epilepsy for which surgery cannot be proposed. The objective of this study was to perform microstimulation to measure the effects of DBS in epilepsy locally at the level of a few neurons, with microelectrode recordings, for the first time in patients with epilepsy. Microelectrode recordings were performed before, during and after microstimulation in nine patients with refractory epilepsy. Neuronal spikes were successfully extracted from multi-unit recordings with clustering in six out of seven patients during hippocampal and in one out of two patients during cortical dysplasia microstimulation (1 Hz, charge-balanced biphasic waveform, 60 μs/ph, 25 μA). The firing rates increased in four out of the six periods of microstimulation that could be analyzed. The firing rates were found higher than before microstimulation in all eight periods with increases reaching significance in six out of eight periods. Low-frequency microstimulation was hence sufficient to induce neuronal excitation lasting beyond the stimulation period. No inhibition was observed. This report presents the first evidence that microstimulation performed in epileptic patients produced locally neuronal excitation. Hence neuronal excitation is shown here as the local mechanism of action of DBS. This local excitation is in agreement with epileptogenic effects of low-frequency hippocampal macrostimulation.
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Affiliation(s)
- Andrea Bartoli
- Department of Neurosurgery, Faculty of Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Rémi Tyrand
- Department of Neurology, Faculty of Medicine, Geneva University Hospitals, Geneva, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Maria I Vargas
- Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Department of Neuroradiology, Faculty of Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Shahan Momjian
- Department of Neurosurgery, Faculty of Medicine, Geneva University Hospitals, Geneva, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Colette Boëx
- Department of Neurology, Faculty of Medicine, Geneva University Hospitals, Geneva, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Epilepsy and Neuromodulation-Randomized Controlled Trials. Brain Sci 2018; 8:brainsci8040069. [PMID: 29670050 PMCID: PMC5924405 DOI: 10.3390/brainsci8040069] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/05/2018] [Accepted: 04/16/2018] [Indexed: 11/16/2022] Open
Abstract
Neuromodulation is a treatment strategy that is increasingly being utilized in those suffering from drug-resistant epilepsy who are not appropriate for resective surgery. The number of double-blinded RCTs demonstrating the efficacy of neurostimulation in persons with epilepsy is increasing. Although reductions in seizure frequency is common in these trials, obtaining seizure freedom is rare. Invasive neuromodulation procedures (DBS, VNS, and RNS) have been approved as therapeutic measures. However, further investigations are necessary to delineate effective targeting, minimize side effects that are related to chronic implantation and to improve the cost effectiveness of these devices. The RCTs of non-invasive modes of neuromodulation whilst showing much promise (tDCS, eTNS, rTMS), require larger powered studies as well as studies that focus at better targeting techniques. We provide a review of double-blinded randomized clinical trials that have been conducted for neuromodulation in epilepsy.
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Queenan BN, Dunn RL, Santos VR, Feng Y, Huizenga MN, Hammack RJ, Vicini S, Forcelli PA, Pak DTS. Kappa opioid receptors regulate hippocampal synaptic homeostasis and epileptogenesis. Epilepsia 2017; 59:106-122. [PMID: 29114861 DOI: 10.1111/epi.13941] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2017] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Homeostatic synaptic plasticity (HSP) serves as a gain control mechanism at central nervous system (CNS) synapses, including those between the dentate gyrus (DG) and CA3. Improper circuit control of DG-CA3 synapses is hypothesized to underlie epileptogenesis. Here, we sought to (1) identify compounds that preferentially modulate DG-CA3 synapses in primary neuronal culture and (2) determine if these compounds would delay or prevent epileptogenesis in vivo. METHODS We previously developed and validated an in vitro assay to visualize the behavior of DG-CA3 synapses and predict functional changes. We used this "synapse-on-chip" assay (quantification of synapse size, number, and type using immunocytochemical markers) to dissect the mechanisms of HSP at DG-CA3 synapses. Using chemogenetic constructs and pharmacological agents we determined the signaling cascades necessary for gain control at DG-CA3 synapses. Finally, we tested the implicated cascades (using kappa opioid receptor (OR) agonists and antagonists) in two models of epileptogenesis: electrical amygdala kindling in the mouse and chemical (pentylenetetrazole) kindling in the rat. RESULTS In vitro, synapses between DG mossy fibers (MFs) and CA3 neurons are the primary homeostatic responders during sustained periods of activity change. Kappa OR signaling is both necessary and sufficient for the homeostatic elaboration of DG-CA3 synapses, induced by presynaptic DG activity levels. Blocking kappa OR signaling in vivo attenuates the development of seizures in both mouse and rat models of epilepsy. SIGNIFICANCE This study elucidates mechanisms by which synapses between DG granule cells and CA3 pyramidal neurons undergo activity-dependent homeostatic compensation, via OR signaling in vitro. Modulation of kappa OR signaling in vivo alters seizure progression, suggesting that breakdown of homeostatic closed-loop control at DG-CA3 synapses contributes to seizures, and that targeting endogenous homeostatic mechanisms at DG-CA3 synapses may prove useful in combating epileptogenesis.
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Affiliation(s)
- Bridget N Queenan
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC, USA.,Department of Mechanical Engineering, Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Raymond L Dunn
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Georgetown Hughes Scholars Program, Department of Biology, Georgetown University, Washington, DC, USA
| | - Victor R Santos
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Yang Feng
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Megan N Huizenga
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Robert J Hammack
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Stefano Vicini
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC, USA
| | - Patrick A Forcelli
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC, USA
| | - Daniel T S Pak
- Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC, USA.,Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC, USA
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Wu G, Wang L, Hong Z, Ren S, Zhou F. Hippocampal low-frequency stimulation inhibits afterdischarge and increases GABA (A) receptor expression in amygdala-kindled pharmacoresistant epileptic rats. Neurol Res 2017; 39:733-743. [PMID: 28502217 DOI: 10.1080/01616412.2017.1325120] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Guofeng Wu
- Department of Neurology, Affiliated Hospital, Guizhou Medical University, Guiyang, P.R. China
- Department of Neurology, Affiliated Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Likun Wang
- Department of Neurology, Affiliated Hospital, Guizhou Medical University, Guiyang, P.R. China
| | - Zhen Hong
- Department of Neurology, Affiliated Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Siying Ren
- Department of Neurology, Affiliated Hospital, Guizhou Medical University, Guiyang, P.R. China
| | - Feng Zhou
- Department of Neurology, Affiliated Hospital, Guizhou Medical University, Guiyang, P.R. China
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Wozny TA, Lipski WJ, Alhourani A, Kondylis ED, Antony A, Richardson RM. Effects of hippocampal low-frequency stimulation in idiopathic non-human primate epilepsy assessed via a remote-sensing-enabled neurostimulator. Exp Neurol 2017; 294:68-77. [PMID: 28495218 DOI: 10.1016/j.expneurol.2017.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 04/28/2017] [Accepted: 05/06/2017] [Indexed: 01/06/2023]
Abstract
Individuals with pharmacoresistant epilepsy remain a large and under-treated patient population. Continued technologic advancements in implantable neurostimulators have spurred considerable research efforts directed towards the development of novel antiepileptic stimulation therapies. However, the lack of adequate preclinical experimental platforms has precluded a detailed understanding of the differential effects of stimulation parameters on neuronal activity within seizure networks. In order to chronically monitor seizures and the effects of stimulation in a freely-behaving non-human primate with idiopathic epilepsy, we employed a novel simultaneous video-intracranial EEG recording platform using a state-of-the-art sensing-enabled, rechargeable clinical neurostimulator with real-time seizure detection and wireless data streaming capabilities. Using this platform, we were able to characterize the electrographic and semiologic features of the focal-onset, secondarily generalizing tonic-clonic seizures stably expressed in this animal. A series of acute experiments exploring low-frequency (2Hz) hippocampal stimulation identified a pulse width (150μs) and current amplitude (4mA) combination which maximally suppressed local hippocampal activity. These optimized stimulation parameters were then delivered to the seizure onset-side hippocampus in a series of chronic experiments. This long-term testing revealed that the suppressive effects of low-frequency hippocampal stimulation 1) diminish when delivered continuously but are maintained when stimulation is cycled on and off, 2) are dependent on circadian rhythms, and 3) do not necessarily confer seizure protective effects.
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Affiliation(s)
- Thomas A Wozny
- Brain Modulation Lab, Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Witold J Lipski
- Brain Modulation Lab, Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Ahmad Alhourani
- Brain Modulation Lab, Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Efstathios D Kondylis
- Brain Modulation Lab, Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Arun Antony
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, United States; University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA 15213, United States
| | - R Mark Richardson
- Brain Modulation Lab, Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA 15213, United States; University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA 15213, United States; University of Pittsburgh Brain Institute, Pittsburgh, PA 15213, United States.
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Sun HL, Zhu W, Zhang YR, Pan XH, Zhang JR, Chen XM, Liu YX, Li SC, Wang QY, Deng DP. Altered glutamate metabolism contributes to antiepileptogenic effects in the progression from focal seizure to generalized seizure by low-frequency stimulation in the ventral hippocampus. Epilepsy Behav 2017; 68:1-7. [PMID: 28109982 DOI: 10.1016/j.yebeh.2016.09.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/04/2016] [Accepted: 09/04/2016] [Indexed: 12/16/2022]
Abstract
As a promising method for treating intractable epilepsy, the inhibitory effect of low-frequency stimulation (LFS) is well known, although its mechanisms remain unclear. Excessive levels of cerebral glutamate are considered a crucial factor for epilepsy. Therefore, we designed experiments to investigate the crucial parts of the glutamate cycle. We evaluated glutamine synthetase (GS, metabolizes glutamate), glutaminase (synthesizes glutamate), and glutamic acid decarboxylase (GAD, a γ-aminobutyric acid [GABA] synthetase) in different regions of the brain, including the dentate gyrus (DG), CA3, and CA1 subregions of the hippocampus, and the cortex, using western blots, immunohistochemistry, and enzyme activity assays. Additionally, the concentrations of glutamate, GABA, and glutamine (a product of GS) were measured using high-performance liquid chromatography (HPLC) in the same subregions. The results indicated that a transiently promoted glutamate cycle was closely involved in the progression from focal to generalized seizure. Low-frequency stimulation (LFS) delivered to the ventral hippocampus had an antiepileptogenic effect in rats exposed to amygdaloid-kindling stimulation. Simultaneously, LFS could partly reverse the effects of the promoted glutamate cycle, including increased GS function, accelerated glutamate-glutamine cycling, and an unbalanced glutamate/GABA ratio, all of which were induced by amygdaloid kindling in the DG when seizures progressed to stage 4. Moreover, glutamine treatment reversed the antiepileptic effect of LFS with regard to both epileptic severity and susceptibility. Our results suggest that the effects of LFS on the glutamate cycle may contribute to the antiepileptogenic role of LFS in the progression from focal to generalized seizure.
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Affiliation(s)
- Hong-Liu Sun
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai 264003, China
| | - Wei Zhu
- Institute of Radiation Medicine, Shandong Academy of Medical Sciences, Jinan 250062, China
| | - Yu-Rong Zhang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai 264003, China
| | - Xiao-Hong Pan
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai 264003, China
| | - Jun-Ru Zhang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai 264003, China
| | - Xiang-Ming Chen
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai 264003, China
| | - Yu-Xia Liu
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai 264003, China
| | - Shu-Cui Li
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai 264003, China
| | - Qiao-Yun Wang
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai 264003, China.
| | - Da-Ping Deng
- Institute of Radiation Medicine, Shandong Academy of Medical Sciences, Jinan 250062, China.
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Cota VR, Drabowski BMB, de Oliveira JC, Moraes MFD. The epileptic amygdala: Toward the development of a neural prosthesis by temporally coded electrical stimulation. J Neurosci Res 2017; 94:463-85. [PMID: 27091311 DOI: 10.1002/jnr.23741] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 03/09/2016] [Accepted: 03/09/2016] [Indexed: 02/06/2023]
Abstract
Many patients with epilepsy do not obtain proper control of their seizures through conventional treatment. We review aspects of the pathophysiology underlying epileptic phenomena, with a special interest in the role of the amygdala, stressing the importance of hypersynchronism in both ictogenesis and epileptogenesis. We then review experimental studies on electrical stimulation of mesiotemporal epileptogenic areas, the amygdala included, as a means to treat medically refractory epilepsy. Regular high-frequency stimulation (HFS) commonly has anticonvulsant effects and sparse antiepileptogenic properties. On the other hand, HFS is related to acute and long-term increases in excitability related to direct neuronal activation, long-term potentiation, and kindling, raising concerns regarding its safety and jeopardizing in-depth understanding of its mechanisms. In turn, the safer regular low-frequency stimulation (LFS) has a robust antiepileptogenic effect, but its pro- or anticonvulsant effect seems to vary at random among studies. As an alternative, studies by our group on the development and investigation of temporally unstructured electrical stimulation applied to the amygdala have shown that nonperiodic stimulation (NPS), which is a nonstandard form of LFS, is capable of suppressing both acute and chronic spontaneous seizures. We hypothesize two noncompetitive mechanisms for the therapeutic role of amygdala in NPS, 1) a direct desynchronization of epileptic circuitry in the forebrain and brainstem and 2) an indirect desynchronization/inhibition through nucleus accumbens activation. We conclude by reintroducing the idea that hypersynchronism, rather than hyperexcitability, may be the key for epileptic phenomena and epilepsy treatment.
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Affiliation(s)
- Vinícius Rosa Cota
- Laboratório Interdisciplinar de Neuroengenharia e Neurociências, Departamento de Engenharia Elétrica (DEPEL), Universidade Federal de São João Del-Rei, São João Del-Rei, Minas Gerais, Brazil
| | - Bruna Marcela Bacellar Drabowski
- Laboratório Interdisciplinar de Neuroengenharia e Neurociências, Departamento de Engenharia Elétrica (DEPEL), Universidade Federal de São João Del-Rei, São João Del-Rei, Minas Gerais, Brazil
| | - Jasiara Carla de Oliveira
- Laboratório Interdisciplinar de Neuroengenharia e Neurociências, Departamento de Engenharia Elétrica (DEPEL), Universidade Federal de São João Del-Rei, São João Del-Rei, Minas Gerais, Brazil
| | - Márcio Flávio Dutra Moraes
- Núcleo de Neurociências, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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Esmaeilpour K, Sheibani V, Shabani M, Mirnajafi-Zadeh J. Effect of low frequency electrical stimulation on seizure-induced short- and long-term impairments in learning and memory in rats. Physiol Behav 2016; 168:112-121. [PMID: 27825910 DOI: 10.1016/j.physbeh.2016.11.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/31/2016] [Accepted: 11/03/2016] [Indexed: 12/21/2022]
Abstract
Kindled seizures can impair learning and memory. In the present study the effect of low-frequency electrical stimulation (LFS) on kindled seizure-induced impairment in spatial learning and memory was investigated and followed up to one month. Animals were kindled by electrical stimulation of hippocampal CA1 area in a semi-rapid manner (12 stimulations per day). One group of animals received four trials of LFS at 30s, 6h, 24h, and 30h following the last kindling stimulation. Each LFS trial was consisted of 4 packages at 5min intervals. Each package contained 200 monophasic square wave pulses of 0.1ms duration at 1Hz. The Open field, Morris water maze, and novel object recognition tests were done 48h, 1week, 2weeks, and one month after the last kindling stimulation respectively. Kindled animals showed a significant impairment in learning and memory compared to control rats. LFS decreased the kindling-induced learning and memory impairments at 24h and one week following its application, but not at 2week or 1month after kindling. In the group of animals that received the same 4 trials of LFS again one week following the last kindling stimulation, the improving effect of LFS was observed even after one month. Obtained results showed that application of LFS in fully kindled animals has a long-term improving effect on spatial learning and memory. This effect can remain for a long duration (one month in this study) by increasing the number of applied LFS.
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Affiliation(s)
- Khadijeh Esmaeilpour
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Vahid Sheibani
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mohammad Shabani
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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Yang AC, Meng DW, Liu HG, Shi L, Zhang K, Qiao H, Yang LC, Hao HW, Li LM, Zhang JG. The ability of anterior thalamic signals to predict seizures in temporal lobe epilepsy in kainate-treated rats. Epilepsia 2016; 57:1369-76. [PMID: 27481634 DOI: 10.1111/epi.13469] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To analyze the local field potential (LFP) of the anterior nucleus of the thalamus (ANT) of epileptic rats using the Generic Osorio-Frei algorithm (GOFA), and to determine the ability of the ANT LFP to predict clinical seizures in temporal lobe epilepsy. METHODS GOFA is an advanced real-time technique used to detect and predict seizures. In this article, GOFA was utilized to process the electrical signals of ANT and the motor cortex recorded in 12 rat models of temporal lobe epilepsy (TLE) induced via the injection of kainic acid into the unilateral hippocampus. The electroencephalography (EEG) data included (1) 161 clinical seizures (each contained a 10-min segment) involving the ANT and cortical regions and (2) one hundred three 10-min segments of randomly selected interictal (no seizure) data. RESULTS Minimal false-positives (0.51 ± 0.36/h) and no false-negatives were detected based on the ANT LFP data processed using GOFA. In ANT LFP, the delay from electrographic onset (EO) to automated onset (AO) was 1.24 ± 0.47 s, and the delay from AO to clinical onset (CO) was 7.73 ± 3.23 s. The AO time occurred significantly earlier in the ANT than in the cortex (p = 0.001). In 75.2% of the clinical onsets predicted by ANT LFP, it was 1.37 ± 0.82 s ahead of the prediction of cortical potentials (CPs), and the remainder were 0.84 ± 0.31 s slower than the prediction of CPs. SIGNIFICANCE ANT LFP appears to be an optimal option for the prediction of seizures in temporal lobe epilepsy. It was possible to upgrade the responsive neurostimulation system to emit electrical stimulation in response to the prediction of epileptic seizures based on the changes in the ANT LFP.
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Affiliation(s)
- An-Chao Yang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Da-Wei Meng
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Huan-Guang Liu
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Lin Shi
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Kai Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Hui Qiao
- Department of Electrophysiology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Lin-Chang Yang
- Institute of Man-Machine and Environmental Engineering, School of Aerospace, Tsinghua University, Beijing, China
| | - Hong-Wei Hao
- Institute of Man-Machine and Environmental Engineering, School of Aerospace, Tsinghua University, Beijing, China
| | - Lu-Ming Li
- Institute of Man-Machine and Environmental Engineering, School of Aerospace, Tsinghua University, Beijing, China
| | - Jian-Guo Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Department of Functional Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
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Wang Y, Ying X, Chen L, Liu Y, Wang Y, Liang J, Xu C, Guo Y, Wang S, Hu W, Du Y, Chen Z. Electroresponsive Nanoparticles Improve Antiseizure Effect of Phenytoin in Generalized Tonic-Clonic Seizures. Neurotherapeutics 2016; 13:603-13. [PMID: 27137202 PMCID: PMC4965401 DOI: 10.1007/s13311-016-0431-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Previously, we developed electroresponsive hydrogel nanoparticles (ERHNPs) modified with angiopep-2 (ANG) to facilitate the delivery of the antiseizure drug phenytoin sodium (PHT). However, the electroresponsive characteristics were not verified directly in epileptic mice and the optimal preparation formula for electroresponsive ability is still unclear. Here, we further synthesized PHT-loaded ANG-ERHNPs (ANG-PHT-HNPs) and PHT-loaded nonelectroresponsive hydrogel nanoparticles (ANG-PHT-HNPs) by changing the content of sodium 4-vinylbenzene sulfonate in the preparation formulae. In vivo microdialysis analysis showed that ANG-PHT-ERHNPs not only have the characteristics of a higher distribution in the central nervous system, but also have electroresponsive ability, which resulted in a strong release of nonprotein-bound PHT during seizures. In both electrical- (maximal electrical shock) and chemical-induced (pentylenetetrazole and pilocarpine) seizure models, ANG-PHT-ERHNPs lowered the effective therapeutic doses of PHT and demonstrated the improved antiseizure effects compared with ANG-PHT-HNPs or PHT solution. These results demonstrate that ANG-ERHNPs are able to transport PHT into the brain efficiently and release them when epileptiform activity occurred, which is due to the content of sodium 4-vinylbenzene sulfonate in formula. This may change the therapeutic paradigm of existing drug treatment for epilepsy into a type of on-demand control for epilepsy in the future.
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Affiliation(s)
- Yi Wang
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoying Ying
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Liying Chen
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yao Liu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Ying Wang
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jiao Liang
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Cenglin Xu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yi Guo
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shuang Wang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Weiwei Hu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yongzhong Du
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, China.
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
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18
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Low-frequency stimulation of the external globus palladium produces anti-epileptogenic and anti-ictogenic actions in rats. Acta Pharmacol Sin 2015; 36:957-65. [PMID: 26095038 DOI: 10.1038/aps.2015.45] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 04/07/2015] [Indexed: 01/03/2023] Open
Abstract
AIM To investigate the anti-epileptic effects of deep brain stimulation targeting the external globus palladium (GPe) in rats. METHODS For inducing amygdala kindling and deep brain stimulation, bipolar stainless-steel electrodes were implanted in SD rats into right basolateral amygdala and right GPe, respectively. The effects of deep brain stimulation were evaluated in the amygdala kindling model, maximal electroshock model (MES) and pentylenetetrazole (PTZ) model. Moreover, the background EEGs in the amygdala and GPe were recorded. RESULTS Low-frequency stimulation (0.1 ms, 1 Hz, 15 min) at the GPe slowed the progression of seizure stages and shortened the after-discharge duration (ADD) during kindling acquisition. Furthermore, low-frequency stimulation significantly decreased the incidence of generalized seizures, suppressed the average stage, and shortened the cumulative ADD and generalized seizure duration in fully kindled rats. In addition, low-frequency stimulation significantly suppressed the average stage of MES-induced seizures and increased the latency to generalized seizures in the PTZ model. High-frequency stimulation (0.1 ms, 130 Hz, 5 min) at the GPe had no anti-epileptic effect and even aggravated epileptogenesis induced by amygdala kindling. EEG analysis showed that low-frequency stimulation at the GPe reversed the increase in delta power, whereas high-frequency stimulation at the GPe had no such effect. CONCLUSION Low-frequency stimulation, but not high-frequency stimulation, at the GPe exerts therapeutic effect on temporal lobe epilepsy and tonic-colonic generalized seizures, which may be due to interference with delta rhythms. The results suggest that modulation of GPe activity using low-frequency stimulation or drugs may be a promising epilepsy treatment.
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Ladas TP, Chiang CC, Gonzalez-Reyes LE, Nowak T, Durand DM. Seizure reduction through interneuron-mediated entrainment using low frequency optical stimulation. Exp Neurol 2015; 269:120-32. [PMID: 25863022 PMCID: PMC4446206 DOI: 10.1016/j.expneurol.2015.04.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 03/20/2015] [Accepted: 04/01/2015] [Indexed: 12/18/2022]
Abstract
Low frequency electrical stimulation (LFS) can reduce neural excitability and suppress seizures in animals and patients with epilepsy. However the therapeutic outcome could benefit from the determination of the cell types involved in seizure suppression. We used optogenetic techniques to investigate the role of interneurons in LFS (1Hz) in the epileptogenic hippocampus. Optical low frequency stimulation (oLFS) was first used to activate the cation channel channelrhodopsin-2 (ChR2) in the Thy1-ChR2 transgenic mouse that expresses ChR2 in both excitatory and inhibitory neurons. We found that oLFS could effectively reduce epileptiform activity in the hippocampus through the activation of GAD-expressing hippocampal interneurons. This was confirmed using the VGAT-ChR2 transgenic mouse, allowing for selective optical activation of only GABA interneurons. Activating hippocampal interneurons through oLFS was found to cause entrainment of neural activity similar to electrical stimulation, but through a GABAA-mediated mechanism. These results confirm the robustness of the LFS paradigm and indicate that GABA interneurons play an unexpected role of shaping inter-ictal activity to decrease neural excitability in the hippocampus.
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Affiliation(s)
- Thomas P Ladas
- Department of Biomedical Engineering, Neural Engineering Center, Case Western Reserve University, Cleveland OH 44106, USA
| | - Chia-Chu Chiang
- Department of Biomedical Engineering, Neural Engineering Center, Case Western Reserve University, Cleveland OH 44106, USA
| | - Luis E Gonzalez-Reyes
- Department of Biomedical Engineering, Neural Engineering Center, Case Western Reserve University, Cleveland OH 44106, USA
| | - Theodore Nowak
- Department of Biomedical Engineering, Neural Engineering Center, Case Western Reserve University, Cleveland OH 44106, USA
| | - Dominique M Durand
- Department of Biomedical Engineering, Neural Engineering Center, Case Western Reserve University, Cleveland OH 44106, USA.
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Van Nieuwenhuyse B, Raedt R, Delbeke J, Wadman W, Boon P, Vonck K. In Search of Optimal DBS Paradigms to Treat Epilepsy: Bilateral Versus Unilateral Hippocampal Stimulation in a Rat Model for Temporal Lobe Epilepsy. Brain Stimul 2015; 8:192-9. [DOI: 10.1016/j.brs.2014.11.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/30/2014] [Accepted: 11/28/2014] [Indexed: 11/28/2022] Open
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21
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Hippocampal low-frequency stimulation increased SV2A expression and inhibited the seizure degree in pharmacoresistant amygdala-kindling epileptic rats. Epilepsy Res 2014; 108:1483-91. [DOI: 10.1016/j.eplepsyres.2014.07.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 07/21/2014] [Accepted: 07/27/2014] [Indexed: 11/19/2022]
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22
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Electrical stimulation of hippocampus for the treatment of refractory temporal lobe epilepsy. Brain Res Bull 2014; 109:13-21. [DOI: 10.1016/j.brainresbull.2014.08.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/21/2014] [Accepted: 08/28/2014] [Indexed: 01/21/2023]
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23
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Cordeiro JG, Somerlik KH, Cordeiro KK, Aertsen A, Araújo JC, Schulze-Bonhage A. Modulation of excitability by continuous low- and high-frequency stimulation in fully hippocampal kindled rats. Epilepsy Res 2013; 107:224-30. [PMID: 24139855 DOI: 10.1016/j.eplepsyres.2013.08.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 07/20/2013] [Accepted: 08/15/2013] [Indexed: 11/17/2022]
Abstract
BACKGROUND Low- and high-frequency stimulation (LFS and HFS, respectively) have been, reported to modify seizure characteristics in rats. We here report effects of hippocampal LFS and HFS, applied at two or four sites in fully kindled rats. METHODS Rats were kindled through a hippocampal tetrode until the fully kindled state. Animals with, stable afterdischarge (AD) threshold were randomly assigned to 5 groups; stimulation at 1Hz (LFS) or, 130Hz (HFS) was continuously applied for 7 days at 2 or 4 intrahippocampal sites; a control, group received no stimulation. Four-contact stimulation was performed in a rotating fashion. Stimulation effects on AD threshold, AD duration and behavioral seizures were assessed. KEY FINDINGS Four-contact LFS consistently increased AD threshold for a period of 2 days to 2 weeks, whereas 4-contact HFS significantly decreased AD duration 24hours following the stimulation period. No significant AD modification was observed with either 2-contact stimulation paradigms. No, behavioral alteration occurred in any group. SIGNIFICANCE These findings suggest that effects of hippocampal stimulation depend on frequency and topography of stimulus application. LFS and HFS had anti-epileptic effect on afterdischarges when applied in a rotating pattern. This supports concepts on patterned stimulation to result in desynchronization and anti-kindling effects.
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Affiliation(s)
- Joacir G Cordeiro
- Epilepsy Center, University Hospital Freiburg, Breisacherstrasse 64, 79106 Freiburg, Germany; Department of Stereotaxic Neurosurgery, University Hospital Freiburg, University of Freiburg, Breisacherstrasse 64, 79106 Freiburg, Germany; Department of Neurosurgery, Hospital de Clinicas, Federal University of Paraná, R: General Carneiro 181, 80060-900 Curitiba, Paraná, Brazil.
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Consecutive 15min is necessary for focal low frequency stimulation to inhibit amygdaloid-kindling seizures in rats. Epilepsy Res 2013; 106:47-53. [DOI: 10.1016/j.eplepsyres.2013.06.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 05/20/2013] [Accepted: 06/25/2013] [Indexed: 11/23/2022]
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25
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Sun HL, Zhang SH, Zhong K, Xu ZH, Feng B, Yu J, Fang Q, Wang S, Wu DC, Zhang JM, Chen Z. A Transient Upregulation of Glutamine Synthetase in the Dentate Gyrus Is Involved in Epileptogenesis Induced by Amygdala Kindling in the Rat. PLoS One 2013; 8:e66885. [PMID: 23825580 PMCID: PMC3688959 DOI: 10.1371/journal.pone.0066885] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Accepted: 05/13/2013] [Indexed: 02/06/2023] Open
Abstract
Reduction of glutamine synthetase (GS) function is closely related to established epilepsy, but little is known regarding its role in epileptogenesis. The present study aimed to elucidate the functional changes of GS in the brain and its involvement in epileptogenesis using the amygdala kindling model of epilepsy induced by daily electrical stimulation of basolateral amygdala in rats. Both expression and activity of GS in the ipsilateral dentate gyrus (DG) were upregulated when kindled seizures progressed to stage 4. A single dose of L-methionine sulfoximine (MSO, in 2 µl), a selective GS inhibitor, was administered into the ipsilateral DG on the third day following the first stage 3 seizure (just before GS was upregulated). It was found that low doses of MSO (5 or 10 µg) significantly and dose-dependently reduced the severity of and susceptibility to evoked seizures, whereas MSO at a high dose (20 µg) aggravated kindled seizures. In animals that seizure acquisition had been successfully suppressed with 10 µg MSO, GS upregulation reoccurred when seizures re-progressed to stage 4 and re-administration of 10 µg MSO consistently reduced the seizures. GLN at a dose of 1.5 µg abolished the alleviative effect of 10 µg MSO and deleterious effect of 20 µg MSO on kindled seizures. Moreover, appropriate artificial microRNA interference (1 and 1.5×10(6) TU/2 µl) of GS expression in the ipsilateral DG also inhibited seizure progression. In addition, a transient increase of GS expression and activity in the cortex was also observed during epileptogenesis evoked by pentylenetetrazole kindling. These results strongly suggest that a transient and region-specific upregulation of GS function occurs when epilepsy develops into a certain stage and eventually promotes the process of epileptogenesis. Inhibition of GS to an adequate degree and at an appropriate timing may be a potential therapeutic approach to interrupting epileptogenesis.
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Affiliation(s)
- Hong-Liu Sun
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Department of Pharmacology, Binzhou Medical University, Yantai, China
| | - Shi-Hong Zhang
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Kai Zhong
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zheng-Hao Xu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Bo Feng
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jie Yu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qi Fang
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shuang Wang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Deng-Chang Wu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jian-Min Zhang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhong Chen
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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Abstract
Deep brain stimulation for seizures has been applied to cerebellum, caudate, locus coeruleus, subthalamic nucleus, mammillary bodies, centromedian thalamus, anterior nucleus of thalamus, hippocampus and amygdala, hippocampal commissure, corpus callosum, neocortex, and occasionally to other sites. Animal and clinical studies have primarily investigated seizure prevention and, to a lessersmaller extent, seizure interruption. No studies have yet shown stimulation able to cure epilepsy. A wide variety of stimulation parameters have been employed in multiple different combinations of frequencies, amplitudes, and durations. Literature review identifies at least 52 clinical studies of brain stimulation for epilepsy in 817 patients. Two studies were large, randomized, and controlled, one in the anterior nucleus of thalamus and another at the cortical or hippocampal seizure focus; both of these studies showed efficacy and tolerability of stimulation. Many questions remain. We do not know the mechanisms, the best stimulation parameters, the best patient population, or how to predict benefit in advance. We do not know why benefit of neurostimulation for epilepsy seems to increase over time or whether there are long-term deleterious effects. All of these questions may be answerable with a combination of laboratory research and clinical experience.
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Affiliation(s)
- Robert S Fisher
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA.
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27
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Fiber tract stimulation can reduce epileptiform activity in an in-vitro bilateral hippocampal slice preparation. Exp Neurol 2012; 240:28-43. [PMID: 23123405 DOI: 10.1016/j.expneurol.2012.10.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 10/24/2012] [Indexed: 11/21/2022]
Abstract
Mesial temporal lobe epilepsy (MTLE) is a common medically refractory neurological disease that has been treated with electrical stimulation of gray matter with limited success. However, stimulation of a white matter tract connecting the hippocampi could maximize treatment efficacy and extent. We tested low-frequency stimulation (LFS) of a novel target that enables simultaneous targeting of bilateral hippocampi: the ventral hippocampal commissure (VHC) with a novel in-vitro slice preparation containing bilateral hippocampi connected by the VHC. The goal of this study is to understand the role of hippocampal interplay in seizure propagation and reduction by commissural fiber tract stimulation. LFS is applied to the VHC as extracellular and intracellular recording techniques are combined with signal processing to estimate several metrics of epilepsy including: (1) total time occupied by seizure activity (%); (2) seizure duration (s); (3) seizures per minute (#); and (4) power in the ictal (V(2)Hz(-1)); as well as (5) interictal spectra (V(2)Hz(-1)). Bilateral epileptiform activity in this preparation is highly correlated between hippocampi. Application of LFS to the VHC reduces all metrics of epilepsy during treatment in an amplitude and frequency dependent manner. This study lends several insights into the mechanisms of bilateral seizure reduction by LFS of the VHC, including that depolarization blocking, LTD/LTP and GABA(A) are not involved. Importantly, enhanced post-stimulation 1-Hz spiking correlates with long-lasting seizure reduction and both are heightened by targeting bilateral hippocampi via the VHC. Therefore, stimulating bilateral hippocampi via a single electrode in the VHC may provide an effective MTLE treatment.
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Wu C, Sharan AD. Neurostimulation for the Treatment of Epilepsy: A Review of Current Surgical Interventions. Neuromodulation 2012; 16:10-24; discussion 24. [DOI: 10.1111/j.1525-1403.2012.00501.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Wu G, Hong Z, Li Y, Zhou F, Shi J. Effects of low-frequency hippocampal stimulation on gamma-amino butyric acid type B receptor expression in pharmacoresistant amygdaloid kindling epileptic rats. Neuromodulation 2012; 16:105-13. [PMID: 22882360 DOI: 10.1111/j.1525-1403.2012.00493.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To observe the effect of low-frequency hippocampal stimulation on gamma-amino butyric acid type B (GABA-B) receptor expression in hippocampus pharmacoresistant epileptic rats. MATERIALS AND METHODS Sixteen pharmacoresistant epileptic rats were selected by testing their seizure response to phenytoin and phenobarbital, and they were randomly divided into a pharmacoresistant control group (PRC group, eight rats) and a pharmacoresistant stimulation group (PRS group, eight rats). Another 16 pharmacosensitive epileptic rats were served as control, also divided randomly into a pharmacosensitive control group (PSC group) and a pharmacosensitive stimulation group (PSS group). A stimulation electrode was implanted into the rats' hippocampus in the four groups. Low-frequency hippocampal stimulation was administered twice per day for two weeks. Following these weeks of stimulation, GABA-B receptor-positive neurons were counted and the gray values of GABA-B receptor expression in the rats' hippocampal tissues were measured. RESULTS The amygdale stimulus-induced epileptic seizures were decreased significantly in the PRS group compared with the PRC group. The parameters of the amygdale after discharge also were improved after hippocampal stimulation. Simultaneously, the GABA-B receptor-positive neurons increased and the GABA-B expression gray values decreased markedly in the PRS group compared with the PRC group. The same phenomenon also was observed between the PSS group and the PSC group. However, no significant difference was found in the GABA-B receptor-positive neurons and the gray values of GABA-B between the PRS group and the PSC group. CONCLUSIONS The low-frequency hippocampal stimulation may inhibit the amygdale stimulus-induced epileptic seizures and the after discharges. The antiepileptic effects of the hippocampal stimulation may be achieved partly by increasing the expression of the GABA-B receptor.
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Affiliation(s)
- Guofeng Wu
- Department of Neurology, Affiliated Hospital, Guiyang Medical College, Guiyang City, Guizhou Province, China
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Wide therapeutic time-window of low-frequency stimulation at the subiculum for temporal lobe epilepsy treatment in rats. Neurobiol Dis 2012; 48:20-6. [PMID: 22659307 DOI: 10.1016/j.nbd.2012.05.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 05/07/2012] [Accepted: 05/24/2012] [Indexed: 11/22/2022] Open
Abstract
Low-frequency stimulation (LFS) has been considered as an option for the treatment of intractable epilepsy. However, previous data showed that LFS of certain brain regions only exerts its effect within a very narrow therapeutic time window, which lasts from seconds to tens of seconds, thus restricting its clinical application. The present study was designed to determine whether there exists a target with a wider therapeutic window for LFS treatment. Therefore, evoked seizures in the rat were induced by amygdala kindling and spontaneous seizures were induced by pilocarpine. The effects of different modes of LFS at the subiculum on the progression and severity of evoked seizures and the frequency of spontaneous seizure were evaluated. We found that (i) LFS at 1Hz delivered to the subiculum before and immediately after the kindling stimulations, or after the cessation of afterdischarge (afterdischarge duration, ADD) decreased the seizure stages and shortened the ADD both in seizure acquisition and expression in amygdaloid-kindled seizures. In addition, even LFS delivered after duration of double the ADD prolonged the kindling progression. (ii) LFS delivered at 1Hz, but not 0.5, 3 or 130Hz, immediately after the cessation of kindling stimulations retarded the progression of kindling seizures. (iii) Pilocarpine-induced spontaneous seizures were completely inhibited by 1Hz LFS. Thus, these results demonstrated that LFS of the subiculum has a wide therapeutic time-window for temporal lobe epilepsy treatment in rats, suggesting that the subiculum may be a promising and suitable target for clinical application.
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Effect of low-frequency electrical stimulation parameters on its anticonvulsant action during rapid perforant path kindling in rat. Epilepsy Res 2012; 99:69-77. [DOI: 10.1016/j.eplepsyres.2011.10.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 10/13/2011] [Accepted: 10/15/2011] [Indexed: 11/20/2022]
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Wang C, Wu H, He F, Jing X, Liang Q, Heng G, Wang L, Gao G, Zhang H. Alleviation of Ferric Chloride-Induced Seizures and Retarded Behaviour in Epileptic Rats by Cortical Electrical Stimulation Treatment. J Int Med Res 2012; 40:266-81. [PMID: 22429366 DOI: 10.1177/147323001204000127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE: To study the effects of low-frequency cortical electrical stimulation (CES) on seizures and behaviour in a rat model of epilepsy induced by ferric chloride (FeCl3). METHODS: Rats were randomly assigned into four groups ( n = 8 per group): normal healthy rats; saline-treated control rats; FeCl3-induced epileptic rats; CES-treated FeCl3-induced epileptic rats. Behavioural tests, analysis of the levels of brain-derived neurotrophic factor (BDNF) protein in brain tissue, and ultrastructural studies using transmission electron microscopy (TEM) were undertaken. RESULTS: CES significantly decreased the number and grade of seizures, and improved rat behaviour, compared with untreated epileptic rats. CES reduced levels of BDNF protein in the forebrain and increased levels of BDNF protein in the hippocampus compared with untreated epileptic rats. TEM showed less damage and ultrastructural changes in the neurons of CES-treated epileptic rats. CONCLUSIONS: CES inhibited seizures in FeCl3-induced epileptic rats and improved their behaviour. These effects might be mediated by altering BDNF protein levels in the brain.
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Affiliation(s)
- C Wang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, ShanXi, Xi'an, China
| | - H Wu
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, ShanXi, Xi'an, China
| | - F He
- Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, ShanXi, Xi'an, China
| | - X Jing
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, ShanXi, Xi'an, China
| | - Q Liang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, ShanXi, Xi'an, China
| | - G Heng
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, ShanXi, Xi'an, China
| | - L Wang
- Department of Biomedical Engineering, Fourth Military Medical University, ShanXi, Xi'an, China
| | - G Gao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, ShanXi, Xi'an, China
| | - H Zhang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, ShanXi, Xi'an, China
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Toibaro L, Pereyra M, Pastorino J, Smigliani A, Ocariz F, Ortmann G, Galardi MM, Gori MB, Kochen S. Effect of Unilateral Low-Frequency Stimulation of Hippocampus on Rapid Kindling—Induced Seizure Development in Rats. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/nm.2012.32022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Rashid S, Pho G, Czigler M, Werz MA, Durand DM. Low frequency stimulation of ventral hippocampal commissures reduces seizures in a rat model of chronic temporal lobe epilepsy. Epilepsia 2011; 53:147-56. [PMID: 22150779 DOI: 10.1111/j.1528-1167.2011.03348.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE To investigate the effects of low frequency stimulation (LFS) of a fiber tract for the suppression of spontaneous seizures in a rat model of human temporal lobe epilepsy. METHODS Stimulation electrodes were implanted into the ventral hippocampal commissure (VHC) in a rat post-status epilepticus (SE) model of human temporal lobe epilepsy (n = 7). Two recording electrodes were placed in the CA3 regions bilaterally and neural data were recorded for a minimum of 6 weeks. LFS (60 min train of 1 Hz biphasic square wave pulses, each 0.1 ms in duration and 200 μA in amplitude, followed by 15 min of rest) was applied to the VHC for 2 weeks, 24 h a day. KEY FINDINGS The baseline mean seizure frequency of the study animals was 3.7 seizures per day. The seizures were significantly reduced by the application of LFS in every animal (n = 7). By the end of the 2-week period of stimulation, there was a significant, 90% (<1 seizure/day) reduction of seizure frequencies (p < 0.05) and a 57% reduction during the period following LFS (p < 0.05) when compared to baseline. LFS also resulted in a significant reduction of hippocampal interictal spike frequency (71%, p < 0.05), during 2 weeks of LFS session. The hippocampal histologic analysis showed no significant difference between rats that received LFS and SE induction and those that had received only SE-induction. None of the animals showed any symptomatic hemorrhage, infection, or complication. SIGNIFICANCE Low frequency stimulation applied at a frequency of 1 Hz significantly reduced both the excitability of the neural tissue as well as the seizure frequency in a rat model of human temporal lobe epilepsy. The results support the hypothesis that LFS of fiber tracts can be an effective method for the suppression of spontaneous seizures in a temporal lobe model of epilepsy in rats and could lead to the development of a new therapeutic modality for human patients with temporal lobe epilepsy.
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Affiliation(s)
- Saifur Rashid
- Department of Biomedical Engineering, Neural Engineering Center, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Anticonvulsant effect of unilateral anterior thalamic high frequency electrical stimulation on amygdala-kindled seizures in rat. Brain Res Bull 2011; 87:221-6. [PMID: 22178354 DOI: 10.1016/j.brainresbull.2011.11.023] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 12/27/2022]
Abstract
Deep brain stimulation (DBS) is an emerging treatment of epilepsy. Anterior nucleus of the thalamus (ANT) is considered to be an attractive target due to its close connection to the limbic structures and wide regions of neocortex. In this study, we examined the effect of unilateral high frequency stimulation (HFS) of the ANT on amygdala-kindled seizures in Wistar rats. When fully-kindled seizures were achieved by daily amygdala kindling, HFS (15 min train of 100 μs pulses at 200 Hz and 450-800 μA) was delivered to the ipsilateral or contralateral ANT immediately before the kindling stimulation for 15 days. HFS of the ipsilateral ANT significantly decreased the incidence of generalized seizures and the mean behavioral seizure stage and afterdischarge duration (ADD), and shortened cumulative ADD and cumulative generalized seizure duration. Furthermore, HFS of the ipsilateral ANT significantly increased the afterdischarge threshold (ADT). Our data suggest that unilateral HFS of the ANT may be an effective method of inhibiting kindled seizures by suppressing the susceptibility to seizures and generating long lasting anti-epileptic effect preventing the recurrence of kindled seizures, providing an alternative to bilateral ANT DBS for refractory epilepsy.
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Wang S, Wu DC, Fan XN, Zhu MZ, Hu QY, Zhou D, Ding MP, Chen Z. Mediodorsal thalamic stimulation is not protective against seizures induced by amygdaloid kindling in rats. Neurosci Lett 2010; 481:97-101. [PMID: 20600600 DOI: 10.1016/j.neulet.2010.06.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 06/17/2010] [Accepted: 06/21/2010] [Indexed: 11/25/2022]
Abstract
Deep brain stimulation (DBS) is now emerging as a new option for treating intractable epilepsy. Cumulative studies suggest that the mediodorsal thalamic nucleus (MD) is involved in limbic seizure activity. This study aims to investigate whether DBS of the MD can protect against seizures induced by amygdaloid kindling. We studied the effect of low-frequency stimulation (LFS, 1 Hz) or high-frequency stimulation (HFS, 100 Hz) in the MD on amygdaloid kindling seizures. During the kindling acquisition, DBS in the MD was daily administered immediately after the kindling stimulus or before the kindling stimulus (preemptive DBS). The effects of both post-treatment of DBS and preemptive DBS in the MD on the expression of amygdaloid kindling seizures were evaluated. We found the DBS or preemptive DBS in the MD, either LFS or HFS, did not significantly change the rate of amygdaloid kindling. Similarly, DBS or preemptive DBS in the MD did not significantly change any parameters representing the expression of amygdaloid kindling. Our study suggests that DBS in the MD may have no significant effect on limbic seizures.
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Affiliation(s)
- Shuang Wang
- Department of Pharmacology, Institute of Neuroscience, School of Medicine, Zhejiang University, Hangzhou 310058, China
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Sun HL, Zhang SH, Zhong K, Xu ZH, Zhu W, Fang Q, Wu DC, Hu WW, Xiao B, Chen Z. Mode-dependent effect of low-frequency stimulation targeting the hippocampal CA3 subfield on amygdala-kindled seizures in rats. Epilepsy Res 2010; 90:83-90. [DOI: 10.1016/j.eplepsyres.2010.03.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 03/16/2010] [Accepted: 03/17/2010] [Indexed: 12/01/2022]
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