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Ghasemi Z, Naderi N, Shojaei A, Raoufy MR, Ahmadirad N, Barkley V, Mirnajafi-Zadeh J. Group I metabotropic glutamate receptors contribute to the antiepileptic effect of electrical stimulation in hippocampal CA1 pyramidal neurons. Epilepsy Res 2021; 178:106821. [PMID: 34839145 DOI: 10.1016/j.eplepsyres.2021.106821] [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: 05/31/2021] [Revised: 11/04/2021] [Accepted: 11/16/2021] [Indexed: 11/17/2022]
Abstract
Low-frequency deep brain stimulation (LFS) inhibits neuronal hyperexcitability during epilepsy. Accordingly, the use of LFS as a treatment method for patients with drug-resistant epilepsy has been proposed. However, the LFS antiepileptic mechanisms are not fully understood. Here, the role of metabotropic glutamate receptors group I (mGluR I) in LFS inhibitory action on epileptiform activity (EA) was investigated. EA was induced by increasing the K+ concentration in artificial cerebrospinal fluid (ACSF) up to 12 mM in hippocampal slices of male Wistar rats. LFS (1 Hz, 900 pulses) was delivered to the bundles of Schaffer collaterals at the beginning of EA. The excitability of CA1 pyramidal neurons was assayed by intracellular whole-cell recording. Applying LFS reduced the firing frequency during EA and substantially moved the membrane potential toward repolarization after a high-K+ ACSF washout. In addition, LFS attenuated the EA-generated neuronal hyperexcitability. A blockade of both mGluR 1 and mGluR 5 prevented the inhibitory action of LFS on EA-generated neuronal hyperexcitability. Activation of mGluR I mimicked the LFS effects and had similar inhibitory action on excitability of CA1 pyramidal neurons following EA. However, mGluR I agonist's antiepileptic action was not as strong as LFS. The observed LFS effects were significantly attenuated in the presence of a PKC inhibitor. Altogether, the LFS' inhibitory action on neuronal hyperexcitability following EA relies, in part, on the activity of mGluR I and a PKC-related signaling pathway.
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Affiliation(s)
- Zahra Ghasemi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Nima Naderi
- Department of Pharmacology and Toxicology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Reza Raoufy
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Nooshin Ahmadirad
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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Chou P, Kuo CC. Anticonvulsant vs. Proconvulsant Effect of in situ Deep Brain Stimulation at the Epileptogenic Focus. Front Syst Neurosci 2021; 15:607450. [PMID: 34408632 PMCID: PMC8366291 DOI: 10.3389/fnsys.2021.607450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 07/05/2021] [Indexed: 11/20/2022] Open
Abstract
Since deep brain stimulation (DBS) at the epileptogenic focus (in situ) denotes long-term repetitive stimulation of the potentially epileptogenic structures, such as the amygdala, the hippocampus, and the cerebral cortex, a kindling effect and aggravation of seizures may happen and complicate the clinical condition. It is, thus, highly desirable to work out a protocol with an evident quenching (anticonvulsant) effect but free of concomitant proconvulsant side effects. We found that in the basolateral amygdala (BLA), an extremely wide range of pulsatile stimulation protocols eventually leads to the kindling effect. Only protocols with a pulse frequency of ≤1 Hz or a direct current (DC), with all of the other parameters unchanged, could never kindle the animal. On the other hand, the aforementioned DC stimulation (DCS), even a pulse as short as 10 s given 5 min before the kindling stimuli or a pulse given even to the contralateral BLA, is very effective against epileptogenicity and ictogenicity. Behavioral, electrophysiological, and histological findings consistently demonstrate success in seizure quenching or suppression as well as in the safety of the specific DBS protocol (e.g., no apparent brain damage by repeated sessions of stimulation applied to the BLA for 1 month). We conclude that in situ DCS, with a novel and rational design of the stimulation protocol composed of a very low (∼3% or 10 s/5 min) duty cycle and assuredly devoid of the potential of kindling, may make a successful antiepileptic therapy with adequate safety in terms of little epileptogenic adverse events and tissue damage.
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Affiliation(s)
- Ping Chou
- Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chung-Chin Kuo
- Institute of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
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Rohani R, Aliaghaei A, Abdollahifar MA, Sadeghi Y, Zare L, Dehghan S, Heidari MH. Long-Term Effects of Hippocampal Low-Frequency Stimulation on Pro-Inflammatory Factors and Astrocytes Activity in Kindled Rats. CELL JOURNAL 2021; 23:85-92. [PMID: 33650824 PMCID: PMC7944118 DOI: 10.22074/cellj.2021.7139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/21/2019] [Indexed: 11/26/2022]
Abstract
Objective Epilepsy is accompanied by inflammation, and the anti-inflammatory agents may have anti-seizure effects. In this
investigation, the effect of deep brain stimulation, as a potential therapeutic approach in epileptic patients, was investigated
on seizure-induced inflammatory factors.
Materials and Methods In the present experimental study, rats were kindled by chronic administration of pentylenetetrazol
(PTZ; 34 mg/Kg). The animals were divided into intact, sham, low-frequency deep brain stimulation (LFS), kindled, and kindled
+LFS groups. In kindled+LFS and LFS groups, animals received four trains of intra-hippocampal low-frequency deep brain
stimulation (LFS) at 20 minutes, 6, 24, and 30 hours after the last PTZ injection. Each train of LFS contained 200 pulses at
1 Hz, 200 µA, and 0.1 ms pulse width. One week after the last PTZ injection, the Y-maze test was run, and then the rats’
brains were removed, and hippocampal samples were extracted for molecular assessments. The gene expression of two
pro-inflammatory factors [interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α)], and glial fibrillary acidic protein (GFAP)
immunoreactivity (as a biological marker of astrocytes reactivation) were evaluated.
Results Obtained results showed a significant increase in the expression of of interleukin-6 (IL-6), tumor necrosis factor
(TNF)-α, and GFAP at one-week post kindling seizures. The application of LFS had a long-lasting effect and restored all of
the measured changes toward normal values. These effects were gone along with the LFS improving the effect on working
memory in kindled animals.
Conclusion The anti-inflammatory action of LFS may have a role in its long-lasting improving effects on seizure-induced
cognitive disorders.
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Affiliation(s)
- Razieh Rohani
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences and Health Services (SBMU), Tehran, Iran
| | - Abbas Aliaghaei
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences and Health Services (SBMU), Tehran, Iran
| | - Mohammad-Amin Abdollahifar
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences and Health Services (SBMU), Tehran, Iran
| | - Yousef Sadeghi
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences and Health Services (SBMU), Tehran, Iran
| | - Leila Zare
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Samaneh Dehghan
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Hassan Heidari
- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences and Health Services (SBMU), Tehran, Iran.
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Shojaee A, Zareian P, Mirnajafi-Zadeh J. Low-frequency Stimulation Decreases Hyperexcitability Through Adenosine A1 Receptors in the Hippocampus of Kindled Rats. Basic Clin Neurosci 2020; 11:333-347. [PMID: 32963726 PMCID: PMC7502188 DOI: 10.32598/bcn.11.2.1713.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 03/03/2019] [Accepted: 07/20/2019] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION In this study, the role of A1 adenosine receptors in improving the effect of Low-Frequency Electrical Stimulation (LFS) on seizure-induced hyperexcitability of hippocampal CA1 pyramidal neurons was investigated. METHODS A semi-rapid hippocampal kindling model was used to induce seizures in male Wistar rats. Examination of the electrophysiological properties of CA1 pyramidal neurons of the hippocampus using whole-cell patch-clamp recording 48 h after the last kindling stimulation revealed that the application of LFS as two packages of stimulations at a time interval of 6 h for two consecutive days could significantly restore the excitability CA1 pyramidal neurons evidenced by a decreased in the of the number of evoked action potentials and enhancement of amplitude, maximum rise slope and decay slope of the first evoked action potential, rheobase, utilization time, adaptation index, first-spike latency, and post-AHP amplitude. Selective locked of A1 receptors by the administration of 8-Cyclopentyl-1,3-dimethylxanthine (1 μM, 1 μl, i.c.v.) before applying each LFS package, significantly reduced LFS effectiveness in recovering these parameters. RESULTS On the other hand, selective activation of A1 receptors by an injection of N6-cyclohexyladenosine (10 μM, 1 μl, i.c.v.), instead of LFS application, could imitate LFS function in improving these parameters. CONCLUSION It is suggested that LFS exerts its efficacy on reducing the neuronal excitability, partially by activating the adenosine system and activating its A1 receptors.
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Affiliation(s)
- Amir Shojaee
- Department of Physiology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Parvin Zareian
- Department of Physiology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Sadeghian A, Salari Z, Azizi H, Raoufy MR, Shojaei A, Kosarmadar N, Zare M, Rezaei M, Barkley V, Javan M, Fathollahi Y, Mirnajafi-Zadeh J. The role of dopamine D 2-like receptors in a "depotentiation-like effect" of deep brain stimulation in kindled rats. Brain Res 2020; 1738:146820. [PMID: 32251663 DOI: 10.1016/j.brainres.2020.146820] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 01/12/2023]
Abstract
The mechanisms involved in the anti-seizure effects of low-frequency stimulation (LFS) have not been completely determined. However, Gi-protein-coupled receptors, including D2-like receptors, may have a role in mediating these effects. In the present study, the role of D2-like receptors in LFS' anti-seizure action was investigated. Rats were kindled with semi-rapid (6 stimulations per day), electrical stimulation of the hippocampal CA1 area. In LFS-treated groups, subjects received four trials of LFS at 5 min, 6 h, 24 h, and 30 h following the last kindling stimulation. Each LFS set occurred at 5 min intervals, and consisted of 4 trains. Each train contained 200, 0/1 ms long, monophasic square wave pulses at 1 Hz. Haloperidol (D2-like receptors antagonist, 2 µm) and/or bromocriptine (D2-like receptors agonist 2 µg/µlit) were microinjected into the lateral ventricle immediately after the last kindling, before applying LFS. Obtained results showed that applying LFS in fully-kindled subjects led to a depotentiation-like decrease in kindling-induced potentiation and reduced the amplitude and rise slope of excitatory and inhibitory post-synaptic currents in whole-cell recordings from CA1 pyramidal neurons. In addition, LFS restored the kindling-induced, spatial learning and memory impairments in the Barnes maze test. A D2-like receptor antagonist inhibited these effects of LFS, while a D2-like receptor agonist mimicked these effects. In conclusion, a depotentiation-like mechanism may be involved in restoring LFS' effects on learning and memory, and synaptic plasticity. These effects depend on D2-like receptors activity.
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Affiliation(s)
- Azam Sadeghian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Zahra Salari
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Reza Raoufy
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Nastaran Kosarmadar
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Meysam Zare
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mahmoud Rezaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Mohammad Javan
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Yaghoub Fathollahi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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Ghafouri S, Fathollahi Y, Semnanian S, Shojaei A, Asgari A, Ebrahim Amini A, Mirnajafi-Zadeh J. Deep brain stimulation restores the glutamatergic and GABAergic synaptic transmission and plasticity to normal levels in kindled rats. PLoS One 2019; 14:e0224834. [PMID: 31697763 PMCID: PMC6837391 DOI: 10.1371/journal.pone.0224834] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 10/22/2019] [Indexed: 01/13/2023] Open
Abstract
Background The precise effect of low frequency stimulation (LFS) as a newly postulated, anticonvulsant therapeutic approach on seizure-induced changes in synaptic transmission has not been completely determined. Hypothesis In this study, the LFS effect on impaired, synaptic plasticity in kindled rats was investigated. Methods Hippocampal kindled rats received LFS (4 trials consisting of one train of 200 monophasic square waves, 0.1 ms pulse duration, 1 Hz) on four occasions. LTP induction was evaluated using whole-cell recordings of evoked excitatory and inhibitory post-synaptic potentials (EPSPs and IPSPs respectively) in CA1 neurons in hippocampal slices. In addition, the hippocampal excitatory and inhibitory post-synaptic currents (EPSCs and IPSCs), and the gene expression of NR2A, GluR2 and γ2 were evaluated. Results LTP induction was attenuated in excitatory and inhibitory synapses in hippocampal slices of kindled rats. When LFS was applied in kindled animals, LTP was induced in EPSPs and IPSPs. Moreover, LFS increased and decreased the threshold intensities of EPSCs and IPSCs respectively. In kindled animals, NR2A gene expression increased, while γ2 gene expression decreased. GluR2 gene expression did not significantly change. Applying LFS in kindled animals mitigated these changes: No significant differences were observed in NR2A, γ2 and GluR2 gene expression in the kindled+LFS and control groups. Conclusion The application of LFS in kindled animals restored LTP induction in both EPSPs and IPSPs, and returned the threshold intensity for induction of EPSCs, IPSCs and gene expression to similar levels as controls.
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Affiliation(s)
- Samireh Ghafouri
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Yaghoub Fathollahi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Azam Asgari
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
- Département de Neurosciences, Université de Montréal, Montréal, Canada
| | - Azin Ebrahim Amini
- Department of Biomaterial and Biomedical Engineering (IBBME), Faculty of applied sciences, University of Toronto, Toronto, Canada
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
- Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran
- * E-mail:
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San-Juan D, Dávila-Rodríguez DO, Jiménez CR, González MS, Carranza SM, Hernández Mendoza JR, Anschel DJ. Neuromodulation techniques for status epilepticus: A review. Brain Stimul 2019; 12:835-844. [PMID: 31053521 DOI: 10.1016/j.brs.2019.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 04/05/2019] [Accepted: 04/14/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Electroconvulsive therapy (ECT), Vagal Nerve Stimulation (VNS), Transcranial Magnetic Stimulation (TMS) and Deep Brain Stimulation (DBS) are neuromodulation therapies that have been used to treat Status Epilepticus (SE). OBJECTIVE Review the literature about the efficacy and safety of neuromodulation therapies in SE in humans. METHODS We searched studies in PubMed, Scopus, Google Scholar and Science Direct (inception to June 2018). Four review authors independently selected the studies, extracted data and assessed the methodological quality of the studies using the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions, PRISMA guidelines, Oxford and GRADE scales, and Murad et al., 2018 methodological quality and synthesis of case series and case reports. RESULTS We analyzed 27 articles (45 patients) with 4 different neuromodulation therapies. In ECT we found 80% rate of disruption of SE and 5% of adverse events was reported. Using iVNS 15/16 (93.7%) patients resolved the SE. All patients who underwent TMS and DBS aborted SE, however, 50% of patients with DBS had severe adverse events. CONCLUSIONS Case series and case reports suggest that neuromodulation therapies can abort SE in 80-100% of patients (Oxford scale and GRADE were level 4 and D) with a wide range of adverse effects, which claims for prospective studies on the relationship be-tween efficacy and safety.
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Affiliation(s)
- Daniel San-Juan
- Neurophysiology Department, National Institute of Neurology and Neurosurgery Manuel Velasco Suárez, Mexico City, Mexico.
| | | | - Christian Ramos Jiménez
- Faculty of Medicine, Autonomous University of State of Mexico, Toluca de Lerdo, State of Mexico, Mexico
| | | | | | - Jesús Ricardo Hernández Mendoza
- Faculty of Medicine Mexicali, Autonomous University of Baja California, Dr. Humberto Torres Sangines, Mexicali, Baja California, Mexico
| | - David J Anschel
- Comprehensive Epilepsy Center of Long Island, Port Jefferson, NY, USA
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Gharib A, Komaki A, Manoochehri Khoshinani H, Saidijam M, Barkley V, Sarihi A, Mirnajafi-Zadeh J. Intrahippocampal 5-HT 1A receptor antagonist inhibits the improving effect of low-frequency stimulation on memory impairment in kindled rats. Brain Res Bull 2019; 148:109-117. [PMID: 30902574 DOI: 10.1016/j.brainresbull.2019.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 02/22/2019] [Accepted: 03/14/2019] [Indexed: 01/10/2023]
Abstract
In addition to its anticonvulsant effect, low frequency stimulation (LFS) improves learning and memory in kindled animals. In the present study, the role of 5-HT1A receptors in mediating LFS' improving effect on spatial learning and memory was investigated in amygdala-kindled rats. Amygdala kindling was conducted in a semi-rapid kindling stimulations (12 stimulations per day) in male Wistar rats. LFS (4 trains of 0.1 ms pulse duration at 1 Hz, 200 pulses, 50-150 μA, at 5 min intervals) was applied after termination of kindling stimulations. NAD-299 (a selective 5-HT1A receptor antagonist; 2.5 and 5 μg/μl) was microinjected into the hippocampal CA1 before applying LFS. The Morris water maze, and novel object recognition tests were conducted after the last kindling stimulation. Hippocampal samples were also prepared, and 5-HT1A receptor gene expression levels were assessed using quantitative RT-PCR. In kindled animals, LFS reduced impairments in spatial learning and memory in the Morris water maze and novel object recognition tests. Microinjection of NAD doses of 5 μg/μl reduced the effects of LFS on learning and memory. The gene expression level of 5-HT1A receptors increased significantly in the hippocampus of amygdala-kindled rats. However, LFS applied after kindling stimulations inhibited this effect. It seems that activation of 5-HT1A receptors in the CA1 field is necessary for LFS' improving effects on spatial learning and memory in kindled animals; although surprisingly, LFS application prevented the elevation in gene expression of 5-HT1A receptors in kindled animals.
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Affiliation(s)
- Alireza Gharib
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hamed Manoochehri Khoshinani
- Department of Molecular Medicine and Genetics, School of Medicine, Hamedan University of Medical Sciences, Hamadan, Iran
| | - Massoud Saidijam
- Department of Molecular Medicine and Genetics, School of Medicine, Hamedan University of Medical Sciences, Hamadan, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Abdolrahman Sarihi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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Ahmadirad N, Fathollahi Y, Janahmadi M, Shojaei A, Ghasemi Z, Barkley V, Mirnajafi-Zadeh J. Low-Frequency Electrical Stimulation Reduces the Impairment in Synaptic Plasticity Following Epileptiform Activity in Rat Hippocampal Slices through α 1, But Not α 2, Adrenergic Receptors. Neuroscience 2019; 406:176-185. [PMID: 30872164 DOI: 10.1016/j.neuroscience.2019.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 03/03/2019] [Accepted: 03/04/2019] [Indexed: 01/03/2023]
Abstract
Low frequency stimulation (LFS) has anticonvulsant effect and may restore the ability of long-term potentiation (LTP) to the epileptic brain. The mechanisms of LFS have not been completely determined. Here, we showed that LTP induction was impaired following in vitro epileptiform activity (EA) in hippocampal slices, but application of LFS prevented this impairment. Then, we investigated the involvement of α-adrenergic receptors in this effect of LFS. EA was induced by increasing the extracellular K+ concentration to 12 mM and EPSPs were recorded from CA1 neurons in whole cell configuration. EA increased EPSP amplitude from 6.9 ± 0.7 mV to 9.6 ± 0.6 mV. For LTP induction, the Schaffer collaterals were stimulated by high frequency stimulation (HFS; two trains of 100 pulses, 100 Hz at the interval of 20 s). The application of HFS resulted in 40.9 ± 2.3% increase in the amplitude of EPSPs. However, following EA, HFS could not produce any significant changes in EPSP amplitude. Administration of LFS (1 Hz, 900 pulses) to Schaffer collaterals at the beginning of EA restored LTP induction to the hippocampal slices and HFS increased the EPSPs amplitude up to 41.7 ± 3.1% of baseline. When slices were perfused by prazosin (α1-adrenergic receptor antagonist; 10 μM) before and during LFS application, LFS improvement on LTP induction was reduced significantly. Perfusion of slices by yohimbine (α2-adrenergic receptor antagonist; 5 μM) had no effect on LFS action. Therefore, it may be concluded that following epileptiform activity, LFS can improve the impairment of LTP generation through α1, but not α2, adrenergic receptor activity.
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Affiliation(s)
- Nooshin Ahmadirad
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Yaghoub Fathollahi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mahyar Janahmadi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Zahra Ghasemi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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10
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Gharib A, Sayyahi Z, Komaki A, Barkley V, Sarihi A, Mirnajafi-Zadeh J. The role of 5-HT 1A receptors of hippocampal CA1 region in anticonvulsant effects of low-frequency stimulation in amygdala kindled rats. Physiol Behav 2018; 196:119-125. [PMID: 30179595 DOI: 10.1016/j.physbeh.2018.08.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/31/2018] [Accepted: 08/31/2018] [Indexed: 01/24/2023]
Abstract
Low frequency stimulation (LFS) has been proposed as a method in the treatment of epilepsy, but its anticonvulsant mechanism is still unknown. In the current study, the hippocampal CA1 region was microinjected with NAD-299 (a selective 5-HT1A antagonist), and its role in mediating the inhibitory action of LFS on amygdala kindling was investigated. Male Wistar rats were kindled by amygdala stimulation in a semi-rapid kindling manner (12 stimulations per day). LFS (0.1 ms pulse duration at 1 Hz, 200 pulses, 50-150 μA) was applied at 5 min after termination of daily kindling stimulations. NAD (a selective 5-HT1A antagonist) was microinjected into the CA1 region of the hippocampus at the doses of 2.5 and 5 μg/1 μl. An open field test was also run to determine the motor activity of animals in different experimental groups. The application of LFS following daily kindling stimulations reduced the behavioral seizure stages, afterdischarge duration, and stage 5 seizure duration and increased the latency to stage 4 seizure compared to the kindled group. However, microinjection of NAD at the doses of 5 μg/1 μl, but not 2.5 μg/1 μl, blocked the inhibitory effect of LFS on behavioral and electrophysiological parameters in kindled animals. It could be presumed that 5-HT1A receptors in the CA1 area are involved in mediating the antiepileptic effects of LFS.
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Affiliation(s)
- Alireza Gharib
- Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Zeinab Sayyahi
- Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Alireza Komaki
- Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Abdolrahman Sarihi
- Department of Physiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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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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Esmaeilpour K, Sheibani V, Shabani M, Mirnajafi-Zadeh J, Akbarnejad Z. Low Frequency Stimulation Reverses the Kindling-Induced Impairment of Learning and Memory in the Rat Passive-avoidance Test. Basic Clin Neurosci 2018; 9:51-58. [PMID: 29942440 PMCID: PMC6015633 DOI: 10.29252/nirp.bcn.9.1.51] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Introduction: The life quality of patients with epileptic seizures is highly affected by cognitive deficits. Low Frequency Stimulation (LFS) is a novel approach for the treatment of pharmacoresistant epilepsy. The main goal of this research is investigating the possible effect of LFS on seizure-induced cognitive dysfunction. Methods: To this end, the kindled animal were prepared via CA1 electrical stimulation in a semi-rapid way (12 stimulations/day). A group of animals were stimulated with LFS, 4 times at 30 s, 6 h, 24 h, and 30 h after the last kindling stimulation. Applied LFS was administered in 4 packages every 5 minutes. The packages were designed with 200 monophasic 200 monophasic square wave pulses of 0.1 ms duration at 1 Hz. The passive-avoidance test was conducted on all animals in order to measure the learning and memory behavior. Results: Hippocampal kindled rats showed deficits in learning and memory when passive avoidance test was performed. Application of LFS reversed the impairment in learning and memory behavior in kindled rats. At the same time, LFS markedly diminished kindling-induced neuronal loss and atrophy in the hippocampus. Conclusion: LFS may have some protection against seizure-induced cognitive damage in kindled rats.
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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
| | - Zeinab Akbarnejad
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
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Esmaeilpour K, Sheibani V, Shabani M, Mirnajafi-Zadeh J. Low frequency electrical stimulation has time dependent improving effect on kindling-induced impairment in long-term potentiation in rats. Brain Res 2017; 1668:20-27. [DOI: 10.1016/j.brainres.2017.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Revised: 04/28/2017] [Accepted: 05/08/2017] [Indexed: 10/19/2022]
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The antiepileptogenic effect of low-frequency stimulation on perforant path kindling involves changes in regulators of G-protein signaling in rat. J Neurol Sci 2017; 375:450-459. [PMID: 28320185 DOI: 10.1016/j.jns.2017.02.047] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 01/27/2017] [Accepted: 02/20/2017] [Indexed: 02/02/2023]
Abstract
G-protein coupled receptors may have a role in mediating the antiepileptogenic effect of low-frequency stimulation (LFS) on kindling acquisition. This effect is accompanied by changes at the intracellular level of cAMP. In the present study, the effect of rolipram as a phosphodiesterase inhibitor on the antiepileptogenic effect of LFS was investigated. Meanwhile, the expression of αs- and αi-subunit of G proteins and regulators of G-protein signaling (RGS) proteins following LFS application was measured. Male Wistar rats were kindled by perforant path stimulation in a semi-rapid kindling manner (12 stimulations per day) during a period of 6days. Application of LFS (0.1ms pulse duration at 1Hz, 200 pulses, 50-150μA, 5min after termination of daily kindling stimulations) to the perforant path retarded the kindling development and prevented the kindling-induced potentiation and kindling-induced changes in paired pulse indices in the dentate gyrus. Intra-cerebroventricular microinjection of rolipram (0.25μM) partially prevented these LFS effects. Twenty-four hours after the last kindling stimulation, the dentate gyrus was removed and changes in protein expression were measured by Western blotting. There was no significant difference in the expression of α-subunit of Gs and Gi/o proteins in different experimental groups. However, application of LFS during the kindling procedure decreased the expression RGS4 and RGS10 proteins (that reduce the activity of Gi/o) and prevented the kindling-induced decrease of RGS2 protein (which reduces the Gs activity). Therefore, it can be postulated that the Gi/o protein signaling pathways may be involved in antiepileptogenetic effect of LFS, and this is why decreasing the cAMP metabolism by rolipram attenuates this effect of LFS.
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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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Ghafouri S, Fathollahi Y, Javan M, Shojaei A, Asgari A, Mirnajafi-Zadeh J. Effect of low frequency stimulation on impaired spontaneous alternation behavior of kindled rats in Y-maze test. Epilepsy Res 2016; 126:37-44. [DOI: 10.1016/j.eplepsyres.2016.06.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/28/2016] [Accepted: 06/25/2016] [Indexed: 10/21/2022]
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Laxpati NG, Kasoff WS, Gross RE. Deep brain stimulation for the treatment of epilepsy: circuits, targets, and trials. Neurotherapeutics 2014; 11:508-26. [PMID: 24957200 PMCID: PMC4121455 DOI: 10.1007/s13311-014-0279-9] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Deep brain stimulation (DBS) has proven remarkably safe and effective in the treatment of movement disorders. As a result, it is being increasingly applied to a range of neurologic and psychiatric disorders, including medically refractory epilepsy. This review will examine the use of DBS in epilepsy, including known targets, mechanisms of neuromodulation and seizure control, published clinical evidence, and novel technologies. Cortical and deep neuromodulation for epilepsy has a long experimental history, but only recently have better understanding of epileptogenic networks, precise stereotactic techniques, and rigorous trial design combined to improve the quality of available evidence and make DBS a viable treatment option. Nonetheless, underlying mechanisms, anatomical targets, and stimulation parameters remain areas of active investigation.
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Affiliation(s)
- Nealen G. Laxpati
- />Department of Neurosurgery, Emory University School of Medicine, 1365 Clifton Road NE, Atlanta, GA 30322 USA
- />Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA USA
| | - Willard S. Kasoff
- />Division of Neurosurgery, Department of Surgery, University of Arizona, Tucson, AZ USA
| | - Robert E. Gross
- />Department of Neurosurgery, Emory University School of Medicine, 1365 Clifton Road NE, Atlanta, GA 30322 USA
- />Department of Neurology, Emory University School of Medicine, Atlanta, GA USA
- />Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA USA
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Rohani R, Piryaei A, Jahanshahi A, Sadeghi Y, Mirnajafi-Zadeh J. Effect of low-frequency stimulation on kindling induced changes in rat dentate gyrus: an ultrastructural study. Acta Neurol Belg 2014; 114:47-53. [PMID: 23975560 DOI: 10.1007/s13760-013-0243-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Accepted: 08/03/2013] [Indexed: 11/25/2022]
Abstract
It has been shown that low-frequency stimulation (LFS) can induce anticonvulsant effects. In this study, the effect of different LFS frequencies on kindling induced behavioral and ultrastructural changes was investigated. For induction of kindled seizures in rats, stimulating and recording electrodes were implanted in perforant path and dentate gyrus, respectively. Animals were stimulated in a rapid kindling manner. Different groups of animals received LFS at different frequencies (0.5, 1 and 5 Hz) following kindling stimulations and their effects on kindling rate were determined using behavioral and ultrastructural studies. Kindling stimulations were applied for 7 days. Then, the animals were sacrificed and their dentate gyrus was sampled for ultrastructural studies under electron microscopy. All three used LFS frequencies (0.5, 1 and 5 Hz) had a significant inhibitory effect on kindling rate and decreased afterdischarge duration and the number of stimulations to achieve stage 4 and 5 seizures significantly. In addition, application of LFS prevented the increase in the post-synaptic density and induction of concave synaptic vesicles following kindling. There was no significant change between anticonvulsant effects of LFS at different frequencies. Obtained results show that LFS application can prevent the neuronal hyperexcitability by preventing the ultrastructural changes during kindling and this may be one of the mechanisms of LFS anticonvulsant effects.
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Affiliation(s)
- Razieh Rohani
- Department of Biology and Anatomical Sciences, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Evin, 1985717443, Tehran, Iran,
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Termination of Chemoconvulsant-Induced Seizures by Synchronous and Asynchronous Electrical Stimulation of the Hippocampus In-Vivo. Brain Stimul 2013; 6:727-36. [DOI: 10.1016/j.brs.2013.03.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 03/17/2013] [Accepted: 03/18/2013] [Indexed: 11/23/2022] Open
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Davoudi M, Shojaei A, Palizvan MR, Javan M, Mirnajafi-Zadeh J. Comparison between standard protocol and a novel window protocol for induction of pentylenetetrazol kindled seizures in the rat. Epilepsy Res 2013; 106:54-63. [PMID: 23619005 DOI: 10.1016/j.eplepsyres.2013.03.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 03/10/2013] [Accepted: 03/26/2013] [Indexed: 11/18/2022]
Abstract
Experimental models of epilepsy, including pentylenetetrazol (PTZ) chemical kindling, are very important in studying the pathophysiology of epilepsy. The aim of the present study was to provide behavioral, electrophysiological and molecular evidences to confirm the similarities between standard and a modified protocol named window- (win-) PTZ kindling method. Standard PTZ kindling model was induced by injection of PTZ (37.5mg/kg) every other days. In win-PTZ kindling method, animals received 4 initial PTZ injections and the time of 3 last PTZ injections were determined according to the number of PTZ injections in standard PTZ kindling model. The behavioral signs of kindled seizures were observed for 20 min after each PTZ injection. Field potential recordings were done from the dentate gyrus granular cells following perforant path stimulation. In addition, the expression of γ2 subunit of GABAA receptor, NR2A subunit of NMDA receptor, adenosine A1 receptor, α-CaMKII and GAP-43 were evaluated in the hippocampus and dentate gyrus using RT-PCR technique. All the animals in win-PTZ kindling method group achieved fully kindled state after 3 last PTZ injections. There was no significant difference in population spike amplitude and expression of the mentioned genes during kindling acquisition between standard PTZ kindling model and win-PTZ kindling method. The similarities in electrophysiological and molecular parameters remained after 8 days post fully kindled state. Obtained data showed the similarities between this win-PTZ kindling method and standard PTZ kindling model. Thus, it may be suggested that not all PTZ injections are need for induction of PTZ induced fully kindled state.
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Affiliation(s)
- Mahnaz Davoudi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Islamic Republic of Iran
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Xu Z, Wang Y, Jin M, Yue J, Xu C, Ying X, Wu D, Zhang S, Chen Z. Polarity-dependent effect of low-frequency stimulation on amygdaloid kindling in rats. Brain Stimul 2012; 6:190-7. [PMID: 22659019 DOI: 10.1016/j.brs.2012.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 03/15/2012] [Accepted: 04/24/2012] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Low-frequency stimulation (LFS, <5 Hz) has been proposed as an alternative option for the treatment of epilepsy. The stimulation pole, anode and cathode, may make different contributions to the anti-epileptic effect of LFS. OBJECTIVE To determine whether electrode polarity influences the anti-epileptic effect of LFS at the kindling focus in amygdaloid kindling rats. METHODS The effect of bipolar and monopolar (or unipolar) LFS at the amygdala in different polarity directions on amygdaloid kindling acquisition, kindled seizures and electroencephalogram (EEG) were tested. RESULTS Bipolar LFS in the same direction of polarity as the kindling stimulation but not in the reverse direction retarded kindling acquisition. Anodal rather than cathodal monopolar LFS attenuated kindling acquisition and kindled seizures. Bipolar LFS showed a stronger anti-epileptic effect than monopolar LFS. Furthermore, anodal LFS (both bipolar and monopolar) decreased, while cathodal LFS increased the power of the EEG from the amygdala; the main changes in power were in the delta (0.5-4 Hz) band, which was specifically increased during kindling acquisition. CONCLUSIONS Our results provide the first evidence that the effect of LFS at the kindling focus on amygdaloid kindling in rats is polarity-dependent, and this may be due to the different effects of anodal and cathodal LFS on the activity in the amygdala, especially on the delta band activity. So, It is likely that the electrode polarity, especially that for anodal current, is a key factor affecting the clinical effects of LFS on epilepsy.
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Affiliation(s)
- Zhenghao Xu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China and Zhejiang Province Key Laboratory of Neurobiology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou 310058, China
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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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Burnstock G, Krügel U, Abbracchio MP, Illes P. Purinergic signalling: from normal behaviour to pathological brain function. Prog Neurobiol 2011; 95:229-74. [PMID: 21907261 DOI: 10.1016/j.pneurobio.2011.08.006] [Citation(s) in RCA: 315] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/12/2011] [Accepted: 08/15/2011] [Indexed: 02/07/2023]
Abstract
Purinergic neurotransmission, involving release of ATP as an efferent neurotransmitter was first proposed in 1972. Later, ATP was recognised as a cotransmitter in peripheral nerves and more recently as a cotransmitter with glutamate, noradrenaline, GABA, acetylcholine and dopamine in the CNS. Both ATP, together with some of its enzymatic breakdown products (ADP and adenosine) and uracil nucleotides are now recognised to act via P2X ion channels and P1 and P2Y G protein-coupled receptors, which are widely expressed in the brain. They mediate both fast signalling in neurotransmission and neuromodulation and long-term (trophic) signalling in cell proliferation, differentiation and death. Purinergic signalling is prominent in neurone-glial cell interactions. In this review we discuss first the evidence implicating purinergic signalling in normal behaviour, including learning and memory, sleep and arousal, locomotor activity and exploration, feeding behaviour and mood and motivation. Then we turn to the involvement of P1 and P2 receptors in pathological brain function; firstly in trauma, ischemia and stroke, then in neurodegenerative diseases, including Alzheimer's, Parkinson's and Huntington's, as well as multiple sclerosis and amyotrophic lateral sclerosis. Finally, the role of purinergic signalling in neuropsychiatric diseases (including schizophrenia), epilepsy, migraine, cognitive impairment and neuropathic pain will be considered.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK.
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