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Manavi MA, Toutounchian S, Afsahi S, Ebrahim Soltani Z, Mohammad Jafari R, Dehpour AR. Ivermectin Exerts Anticonvulsant Effects Against Status Epilepticus Induced by Lithium-Pilocarpine in Rats via GABA A Receptor and Neuroinflammation Modulation: Possible Interaction of Opioidergic Pathways and K ATP Channel with Nitrergic System. Mol Neurobiol 2024:10.1007/s12035-024-04061-3. [PMID: 38421468 DOI: 10.1007/s12035-024-04061-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/20/2024] [Indexed: 03/02/2024]
Abstract
Status epilepticus (SE) is a critical medical emergency marked by persistent or rapidly repeating seizures, posing a threat to life. Using the lithium-pilocarpine-induced SE model, we decide to evaluate the anti-seizure effects of ivermectin as a positive allosteric modulator of GABAA receptor and the underlying mechanisms involved. Lithium chloride was injected intraperitoneally at a dose of 127 mg/kg, followed by the administration of pilocarpine at a dose of 60 mg/kg after a 20-h interval in order to induce SE. Subsequently, the rats received varying amounts of ivermectin (0.3, 1, 3, 5, and 10 mg/kg, i.p.) 30 min before the onset of SE. To study the underlying molecular mechanisms, we had pharmacological interventions of diazepam (1 mg/kg), glibenclamide and nicorandil as ATP-sensitive potassium channel blocker and opener (both 1 mg/kg, i.p.), naltrexone and morphine, as opioid receptor antagonist and agonist (1 mg/kg and 0.5 mg/kg, i.p., respectively). In addition, three nitric oxide inhibitors, namely, L-NAME (10 mg/kg, i.p.), 7-NI (30 mg/kg, i.p.), and aminoguanidine (100 mg/kg, i.p.), were administered to the rats in the experiment. Finally, we use ELISA and western blotting, respectively, to examine the amounts of pro-inflammatory cytokines (TNF-α and IL-1β), nitrite, and GABAA receptors in the rat hippocampal tissue. The study found that ivermectin, at doses of 3, 5, and 10 mg/kg, exerts anti-seizure effects and decrease Racine's scale SE score. Interestingly glibenclamide and naltrexone reduced the anti-seizure effects of ivermectin, and from other hand diazepam, nicorandil, morphine, L-NAME, 7-NI, and aminoguanidine, enhance the effects when co-administrated with subeffective dose of ivermectin. Additionally, the study found that ivermectin decreased the elevated levels of TNF-α and IL-1β following SE, while increased the reduced expression of GABAA receptors. Overall, these findings suggest that ivermectin has anti-seizure effects in a SE seizure which may be mediated by the modulation of GABAergic, opioidergic, and nitrergic pathways and KATP channels.
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Affiliation(s)
- Mohammad Amin Manavi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran
| | - Samaneh Toutounchian
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Sahar Afsahi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Ebrahim Soltani
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Razieh Mohammad Jafari
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Ahmad M, Alshehry AS, Alharbi H. The Neuroprotective Effects of Natural Food Products Cinnamon and Curcumin in Lithium-Pilocarpine Induced Status Epilepticus Model. NEUROCHEM J+ 2022. [DOI: 10.1134/s1819712422020027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Izadi A, Schedlbauer A, Ondek K, Disse G, Ekstrom AD, Cowen SL, Shahlaie K, Gurkoff GG. Early Intervention via Stimulation of the Medial Septal Nucleus Improves Cognition and Alters Markers of Epileptogenesis in Pilocarpine-Induced Epilepsy. Front Neurol 2021; 12:708957. [PMID: 34557145 PMCID: PMC8452867 DOI: 10.3389/fneur.2021.708957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Over one-third of patients with temporal lobe epilepsy are refractory to medication. In addition, anti-epileptic drugs often exacerbate cognitive comorbidities. Neuromodulation is an FDA treatment for refractory epilepsy, but patients often wait >20 years for a surgical referral for resection or neuromodulation. Using a rodent model, we test the hypothesis that 2 weeks of theta stimulation of the medial septum acutely following exposure to pilocarpine will alter the course of epileptogenesis resulting in persistent behavioral improvements. Electrodes were implanted in the medial septum, dorsal and ventral hippocampus, and the pre-frontal cortex of pilocarpine-treated rats. Rats received 30 min/day of 7.7 Hz or theta burst frequency on days 4-16 post-pilocarpine, prior to the development of spontaneous seizures. Seizure threshold, spikes, and oscillatory activity, as well as spatial and object-based learning, were assessed in the weeks following stimulation. Non-stimulated pilocarpine animals exhibited significantly decreased seizure threshold, increased spikes, and cognitive impairments as compared to vehicle controls. Furthermore, decreased ventral hippocampal power (6-10 Hz) correlated with both the development of spikes and impaired cognition. Measures of spikes, seizure threshold, and cognitive performance in both acute 7.7 Hz and theta burst stimulated animals were statistically similar to vehicle controls when tested during the chronic phase of epilepsy, weeks after stimulation was terminated. These data indicate that modulation of the septohippocampal circuit early after pilocarpine treatment alters the progression of epileptic activity, resulting in elevated seizure thresholds, fewer spikes, and improved cognitive outcome. Results from this study support that septal theta stimulation has the potential to serve in combination or as an alternative to high frequency thalamic stimulation in refractory cases and that further research into early intervention is critical.
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Affiliation(s)
- Ali Izadi
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Amber Schedlbauer
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States
| | - Katelynn Ondek
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Gregory Disse
- Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Arne D Ekstrom
- Department of Psychology, University of Arizona, Tucson, AZ, United States.,McKnight Brain Institute, University of Arizona, Tucson, AZ, United States
| | - Stephen L Cowen
- Department of Psychology, University of Arizona, Tucson, AZ, United States.,McKnight Brain Institute, University of Arizona, Tucson, AZ, United States
| | - Kiarash Shahlaie
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Gene G Gurkoff
- Department of Neurological Surgery, University of California, Davis, Sacramento, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
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Tsegay E, Balasubramanian R, Tuem K, Gebre A. Beneficial effect of moringa stenopetala (bak.f) cuf. on lithium–pilocarpine-induced temporal lobe epilepsy in experimental animals. Pharmacogn Mag 2021. [DOI: 10.4103/pm.pm_276_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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5
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Smolensky IV, Zubareva OE, Kalemenev SV, Lavrentyeva VV, Dyomina AV, Karepanov AA, Zaitsev AV. Impairments in cognitive functions and emotional and social behaviors in a rat lithium-pilocarpine model of temporal lobe epilepsy. Behav Brain Res 2019; 372:112044. [PMID: 31220488 DOI: 10.1016/j.bbr.2019.112044] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 05/29/2019] [Accepted: 06/16/2019] [Indexed: 12/12/2022]
Abstract
The aim of this study was to evaluate in detail behavioral patterns and comorbid disturbances in rats using the lithium-pilocarpine model. A comprehensive set of behavioral tests was used to investigate behavioral patterns, including the open field test, Morris water maze, Y-maze, fear conditioning, the elevated plus maze, the forced swimming test, and the resident-intruder paradigm. Motor and explorative activity, learning and memory, anxiety and depressive-like behavior, aggression, and communication were evaluated 8-15 d after pilocarpine-induced status epilepticus (SE) (latent phase of the model) and 41-53 d (chronic phase) after pilocarpine-induced SE. Increased motor activity and impaired memory function were the most noticeable behavioral modifications in the epileptic rats. Both the movement speed and distance traveled increased in the open field test in both the latent and chronic phases. Significant impairments were detected in short-and long-term spatial memory in the Morris water maze during the latent phase. Besides the alterations in spatial memory, behaviors indicative of short- and long-term fear-associated memory disturbances were observed in the fear conditioning test during the chronic phase of the model. In the resident-intruder paradigm, epileptic rats exhibited disturbed communicative behavior, with impaired social behaviors. In contrast, emotional disturbances were less prominent, with the rats exhibiting decreased anxiety. There were no changes in depressive-like behavior. The data suggest that the lithium-pilocarpine model of TLE in rodents is more useful for studies of comorbid disturbances in memory, hyperactivity, and social behavior than for research on psychoemotional impairments, such as anxiety and depression.
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Affiliation(s)
- Ilya V Smolensky
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg, 194223, Russia
| | - Olga E Zubareva
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg, 194223, Russia
| | - Sergey V Kalemenev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg, 194223, Russia
| | - Valeria V Lavrentyeva
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg, 194223, Russia
| | - Alexandra V Dyomina
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg, 194223, Russia
| | - Anton A Karepanov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg, 194223, Russia
| | - Aleksey V Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS (IEPhB), 44, Toreza pr., Saint Petersburg, 194223, Russia.
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Suleymanova EM, Borisova MA, Vinogradova LV. Early endocannabinoid system activation attenuates behavioral impairments induced by initial impact but does not prevent epileptogenesis in lithium-pilocarpine status epilepticus model. Epilepsy Behav 2019; 92:71-78. [PMID: 30634156 DOI: 10.1016/j.yebeh.2018.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/26/2018] [Accepted: 12/04/2018] [Indexed: 11/30/2022]
Abstract
Mood and anxiety disorders, as well as memory impairments, are important factors affecting quality of life in patients with epilepsy and can influence the antiepileptic therapy. Clinical studies of psychiatric comorbidities are quite complicated to design and interpret, so animal studies of behavioral impairments associated with seizures can be of use. We investigated the effect of early administration of endocannabinoid receptor agonist WIN-55,212-2 on the development of spontaneous seizures, long-term behavioral and memory impairments, and neurodegeneration in the hippocampus on the lithium-pilocarpine model of status epilepticus (SE). We also studied the role of spontaneous seizures in the development of pathologic consequences of the SE. Our results showed that behavioral impairments found in the elevated plus maze test depended mostly on the consequences of SE itself and not on the development of spontaneous seizures while hyperactivity in the open-field test and light-dark chamber was more prominent in rats with spontaneous seizures. Administration of WIN-55,212-2 decreased emotional behavior in the elevated plus maze but did not affect hyperactive behavior in the open-field test. Spatial memory impairment developed both in the presence or absence of spontaneous seizures and was not affected by administration of WIN-55,212-2. Both administration of endocannabinoid receptor agonist WIN-55,212-2 and the presence of spontaneous seizures affected SE-induced neuronal loss in the hippocampus.
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Affiliation(s)
- Elena M Suleymanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, 117485 Butlerova 5A, Moscow, Russia.
| | - Maria A Borisova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, 117485 Butlerova 5A, Moscow, Russia
| | - Lyudmila V Vinogradova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, 117485 Butlerova 5A, Moscow, Russia
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Izadi A, Ondek K, Schedlbauer A, Keselman I, Shahlaie K, Gurkoff G. Clinically indicated electrical stimulation strategies to treat patients with medically refractory epilepsy. Epilepsia Open 2018; 3:198-209. [PMID: 30564779 PMCID: PMC6293066 DOI: 10.1002/epi4.12276] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2018] [Indexed: 12/25/2022] Open
Abstract
Focal epilepsies represent approximately half of all diagnoses, and more than one-third of these patients are refractory to pharmacologic treatment. Although resection can result in seizure freedom, many patients do not meet surgical criteria, as seizures may be multifocal in origin or have a focus in an eloquent region of the brain. For these individuals, several U.S. Food and Drug Administration (FDA)-approved electrical stimulation paradigms serve as alternative options, including vagus nerve stimulation, responsive neurostimulation, and stimulation of the anterior nucleus of the thalamus. All of these are safe, flexible, and lead to progressive seizure control over time when used as an adjunctive therapy to antiepileptic drugs. Focal epilepsies frequently involve significant comorbidities such as cognitive decline. Similar to antiepilepsy medications and surgical resection, current stimulation targets and parameters have yet to address cognitive impairments directly, with patients reporting persistent comorbidities associated with focal epilepsy despite a significant reduction in the number of their seizures. Although low-frequency theta oscillations of the septohippocampal network are critical for modulating cellular activity and, in turn, cognitive processing, the coordination of neural excitability is also imperative for preventing seizures. In this review, we summarize current FDA-approved electrical stimulation paradigms and propose that theta oscillations of the medial septal nucleus represent a novel neuromodulation target for concurrent seizure reduction and cognitive improvement in epilepsy. Ultimately, further advancements in clinical neurostimulation strategies will allow for the efficient treatment of both seizures and comorbidities, thereby improving overall quality of life for patients with epilepsy.
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Affiliation(s)
- Ali Izadi
- Department of Neurological SurgeryUniversity of CaliforniaDavisCalifornia,U.S.A.
| | - Katelynn Ondek
- Department of Neurological SurgeryUniversity of CaliforniaDavisCalifornia,U.S.A.,Center for NeuroscienceUniversity of CaliforniaDavisCalifornia,U.S.A.
| | - Amber Schedlbauer
- Department of Neurological SurgeryUniversity of CaliforniaDavisCalifornia,U.S.A.
| | - Inna Keselman
- Department of Neurological SurgeryUniversity of CaliforniaDavisCalifornia,U.S.A.,Department of NeurologyUniversity of CaliforniaDavisCaliforniaU.S.A.
| | - Kiarash Shahlaie
- Department of Neurological SurgeryUniversity of CaliforniaDavisCalifornia,U.S.A.,Center for NeuroscienceUniversity of CaliforniaDavisCalifornia,U.S.A.
| | - Gene Gurkoff
- Department of Neurological SurgeryUniversity of CaliforniaDavisCalifornia,U.S.A.,Center for NeuroscienceUniversity of CaliforniaDavisCalifornia,U.S.A.
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Eslami SM, Ghasemi M, Bahremand T, Momeny M, Gholami M, Sharifzadeh M, Dehpour AR. Involvement of nitrergic system in anticonvulsant effect of zolpidem in lithium-pilocarpine induced status epilepticus: Evaluation of iNOS and COX-2 genes expression. Eur J Pharmacol 2017; 815:454-461. [DOI: 10.1016/j.ejphar.2017.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 09/27/2017] [Accepted: 10/03/2017] [Indexed: 01/04/2023]
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9
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Persinger MA, Bureau YRJ, Peredery OP, Richards PM. The Sensed Presence as Right Hemispheric Intrusions into the Left Hemispheric Awareness of Self: An Illustrative Case Study. Percept Mot Skills 2017. [DOI: 10.1177/003151259407800358] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The hypothesis of vectorial hemisphericity predicts that left hemispheric intrusions of the right hemispheric equivalent of the sense of self should be associated with the experience of a “presence” of someone else. The neurophenomenological profile of a woman whose medical history satisfied these theoretical criteria (verified electrical anomalies that could encourage phasic discharges within the right temporal lobe and atrophy within the left temporoparietal region) is presented. In addition to interactions between electrical seizures and thinking, she reported a long history of sensed presences, ego-alien intrusions, and “sudden knowing of the subsequent sequences of seizures” before they occurred clinically. The existence of these neurocognitive processes demands a reevaluation of the psychiatric default explanations of “hysteria” and questions the belief that “awareness during seizures” or “premonition of subsequent somatosensory experience” contraindicates an epileptic process.
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Affiliation(s)
- Michael A. Persinger
- Clinical Neuropsychology Laboratory Behavioral Neuroscience Program Laurentian University
| | - Yves R. J. Bureau
- Clinical Neuropsychology Laboratory Behavioral Neuroscience Program Laurentian University
| | - Oksana P. Peredery
- Clinical Neuropsychology Laboratory Behavioral Neuroscience Program Laurentian University
| | - Pauline M. Richards
- Clinical Neuropsychology Laboratory Behavioral Neuroscience Program Laurentian University
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Functional neuroimaging of post-mortem tissue: lithium-pilocarpine seized rats express reduced brain mass and proportional reductions of left ventral cerebral theta spectral power. Heliyon 2016; 2:e00181. [PMID: 27812552 PMCID: PMC5079658 DOI: 10.1016/j.heliyon.2016.e00181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/22/2016] [Accepted: 10/12/2016] [Indexed: 11/22/2022] Open
Abstract
Structural imaging tools can be used to identify neuropathology in post-mortem tissue whereas functional imaging tools including quantitative electroencephalography (QEEG) are thought to be restricted for use in living subjects. We are not aware of any study which has used electrophysiological methods decades after death to infer pathology. We therefore attempted to discriminate between chemically preserved brains which had incurred electrical seizures and those that did not using functional imaging. Our data indicate that modified QEEG technology involving needle electrodes embedded within chemically fixed neural tissue can be used to discriminate pathology. Forty (n = 40) rat brains preserved in ethanol-formalin-acetic acid (EFA) were probed by needle electrodes inserted into the dorsal and ventral components of the left and right cerebral hemispheres. Raw microvolt potentials were converted to spectral power densities within classical electroencephalographic frequency bands (1.5 Hz to 40 Hz). Brain mass differences were shown to scale with left hemispheric ventral theta-band spectral power densities in lithium-pilocarpine seized rats. This relationship was not observed in non-seized rats. A conspicuous absence of pathological indicators within dorsal regions as inferred by microvolt fluctuations was expected given the known localization of post-ictal damage in lithium-pilocarpine seized rats. Together, the data demonstrate that post-mortem neuroimaging is both possible and potentially useful as a means to identify neuropathology without structural imaging techniques or dissection.
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Desjardins D, Persinger MA. Association between Intermale Social Aggression and Cellular Density within the Central Amygdaloid Nucleus in Rats with Lithium/Pilocarpine-Induced Seizures. Percept Mot Skills 2016; 81:635-41. [PMID: 8570370 DOI: 10.1177/003151259508100254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aggressive behaviors (numbers of bites/hour) within groups ( ns = 8) of normal rats and rats in which seizures had been induced by a single systemic injection of lithium/pilocarpine were observed for 11 successive, 1-hr. periods. Mean numbers of neurons and glial cells were counted for 10 different nuclei of the amygdala for 16 different brains (8 control; 8 seizure). Although there was no significant difference found between rats with chronically induced seizures and controls for the numbers of neurons per area within the central medial amygdaloid nucleus, the neuronal density was correlated significantly (.92) with mean numbers of bites per hour for the chronically epileptic group only. The hypothesis that seizure-induced damage within proximal amygdaloid nuclei disinhibits the central nucleus and encourages aggression was supported.
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Affiliation(s)
- D Desjardins
- Behavioural Neuroscience Program, Laurentian University, Sudbury, Ontario, Canada
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Taketa Y, Shiotani M, Tsuru Y, Kotani S, Osada Y, Fukushima T, Inomata A, Hosokawa S. Application of a compact magnetic resonance imaging system for toxicologic pathology: evaluation of lithium-pilocarpine-induced rat brain lesions. J Toxicol Pathol 2015; 28:217-24. [PMID: 26538811 PMCID: PMC4604131 DOI: 10.1293/tox.2015-0043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 08/07/2015] [Indexed: 11/29/2022] Open
Abstract
Magnetic resonance imaging (MRI) is a useful noninvasive tool used to detect lesions in clinical and veterinary medicine. The present study evaluated the suitability of a new easy-to-use compact MRI platform (M2 permanent magnet system, Aspect Imaging, Shoham, Israel) for assisting with preclinical toxicologic pathology examination of lesions in the rat brain. In order to induce brain lesions, male Sprague-Dawley rats were treated once with lithium chloride (127 mg/kg, intraperitoneal [i.p.]) followed by pilocarpine (30 mg/kg, i.p.). One week after dosing, the perfused, fixed brains were collected, analyzed by the MRI system and examined histopathologically. MRI of the brain of treated rats revealed areas of high T1 and middle to low T2 signals, when compared with the controls, in the piriform cortex, lateral thalamic nucleus, posterior paraventricular thalamic nucleus and posterior hypothalamic nucleus of the cerebrum. The altered MRI signal areas were consistent with well-circumscribed foci of neuronal cell degeneration/necrosis accompanied by glial cell proliferation. The present data demonstrated that quick analysis of fixed organs by the MRI system can detect the presence and location of toxicologic lesions and provide useful temporal information for selection of appropriate sections for histopathologic examination before routine slide preparation, especially in complex and functionally heterogeneous organs such as the brain.
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Affiliation(s)
- Yoshikazu Taketa
- Tsukuba Drug Safety, Global Drug Safety, Biopharmaceutical Assessments Core Function Unit, Eisai Product Creation Systems, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Motohiro Shiotani
- Tsukuba Drug Safety, Global Drug Safety, Biopharmaceutical Assessments Core Function Unit, Eisai Product Creation Systems, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Yoshiharu Tsuru
- Research Support Department, Primetech Corp., 1-3-25 Koishikawa, Bunkyo-ku, Tokyo 112-0002, Japan
| | - Sadaharu Kotani
- Neuroscience and General Medicine Product Creation Unit, Eisai Product Creation Systems, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Yoshihide Osada
- Neuroscience and General Medicine Product Creation Unit, Eisai Product Creation Systems, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Tatsuto Fukushima
- Neuroscience and General Medicine Product Creation Unit, Eisai Product Creation Systems, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Akira Inomata
- Tsukuba Drug Safety, Global Drug Safety, Biopharmaceutical Assessments Core Function Unit, Eisai Product Creation Systems, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Satoru Hosokawa
- Tsukuba Drug Safety, Global Drug Safety, Biopharmaceutical Assessments Core Function Unit, Eisai Product Creation Systems, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
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The effects of quinacrine, proglumide, and pentoxifylline on seizure activity, cognitive deficit, and oxidative stress in rat lithium-pilocarpine model of status epilepticus. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:630509. [PMID: 25478062 PMCID: PMC4248364 DOI: 10.1155/2014/630509] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 10/05/2014] [Accepted: 10/19/2014] [Indexed: 12/18/2022]
Abstract
The present data indicate that status epilepticus (SE) induced in adult rats is associated with cognitive dysfunctions and cerebral oxidative stress (OS). This has been demonstrated using lithium-pilocarpine (Li-Pc) model of SE. OS occurring in hippocampus and striatum of mature brain following SE is apparently due to both the increased free radicals production and the limited antioxidant defense. Pronounced alterations were noticed in the enzymatic, glutathione-S transferase (GST), catalase (CAT), and superoxide dismutase (SOD), as well as in the nonenzymatic; thiobarbituric acid (TBARS) and reduced glutathione (GST), indices of OS in the hippocampus and striatum of SE induced animals. Quinacrine (Qcn), proglumide (Pgm), and pentoxifylline (Ptx) administered to animals before inducing SE, were significantly effective in ameliorating the seizure activities, cognitive dysfunctions, and cerebral OS. The findings suggest that all the drugs were effective in the order of Ptx < Pgm < Qcn indicating that these drugs are potentially antiepileptic as well as antioxidant; however, further studies are needed to establish this fact. It can be assumed that these antiepileptic substances with antioxidant properties combined with conventional therapies might provide a beneficial effect in treatment of epilepsy through ameliorating the cerebral OS.
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Faure JB, Marques-Carneiro JE, Akimana G, Cosquer B, Ferrandon A, Herbeaux K, Koning E, Barbelivien A, Nehlig A, Cassel JC. Attention and executive functions in a rat model of chronic epilepsy. Epilepsia 2014; 55:644-653. [PMID: 24621352 DOI: 10.1111/epi.12549] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Temporal lobe epilepsy is a relatively frequent, invalidating, and often refractory neurologic disorder. It is associated with cognitive impairments that affect memory and executive functions. In the rat lithium-pilocarpine temporal lobe epilepsy model, memory impairment and anxiety disorder are classically reported. Here we evaluated sustained visual attention in this model of epilepsy, a function not frequently explored. METHODS Thirty-five Sprague-Dawley rats were subjected to lithium-pilocarpine status epilepticus. Twenty of them received a carisbamate treatment for 7 days, starting 1 h after status epilepticus onset. Twelve controls received lithium and saline. Five months later, attention was assessed in the five-choice serial reaction time task, a task that tests visual attention and inhibitory control (impulsivity/compulsivity). Neuronal counting was performed in brain regions of interest to the functions studied (hippocampus, prefrontal cortex, nucleus basalis magnocellularis, and pedunculopontine tegmental nucleus). RESULTS Lithium-pilocarpine rats developed motor seizures. When they were able to learn the task, they exhibited attention impairment and a tendency toward impulsivity and compulsivity. These disturbances occurred in the absence of neuronal loss in structures classically related to attentional performance, although they seemed to better correlate with neuronal loss in hippocampus. Globally, rats that received carisbamate and developed motor seizures were as impaired as untreated rats, whereas those that did not develop overt motor seizures performed like controls, despite evidence for hippocampal damage. SIGNIFICANCE This study shows that attention deficits reported by patients with temporal lobe epilepsy can be observed in the lithium-pilocarpine model. Carisbamate prevents the occurrence of motor seizures, attention impairment, impulsivity, and compulsivity in a subpopulation of neuroprotected rats.
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Affiliation(s)
- Jean-Baptiste Faure
- Laboratory of Cognitive and Adaptive Neuroscience (LNCA), Faculty of Psychology, UMR 7364 University of Strasbourg - CNRS, Strasbourg, France; Faculty of Medicine, INSERM U 666, Strasbourg, France
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15
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Faure JB, Akimana G, Carneiro JEM, Cosquer B, Ferrandon A, Geiger K, Koning E, Penazzi L, Cassel JC, Nehlig A. A comprehensive behavioral evaluation in the lithium-pilocarpine model in rats: Effects of carisbamate administration during status epilepticus. Epilepsia 2013; 54:1203-13. [DOI: 10.1111/epi.12219] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Jean-Baptiste Faure
- Faculty of Medicine; INSERM U 666; Strasbourg France
- Laboratory of Cognitive and Adaptive Neuroscience; CNRS-UDS UMR 7364; Strasbourg France
| | - Gladys Akimana
- Faculty of Medicine; INSERM U 666; Strasbourg France
- Laboratory of Cognitive and Adaptive Neuroscience; CNRS-UDS UMR 7364; Strasbourg France
| | - José E. M. Carneiro
- Faculty of Medicine; INSERM U 666; Strasbourg France
- Laboratory of Cognitive and Adaptive Neuroscience; CNRS-UDS UMR 7364; Strasbourg France
| | - Brigitte Cosquer
- Laboratory of Cognitive and Adaptive Neuroscience; CNRS-UDS UMR 7364; Strasbourg France
| | | | - Karin Geiger
- Laboratory of Cognitive and Adaptive Neuroscience; CNRS-UDS UMR 7364; Strasbourg France
| | | | - Lorène Penazzi
- Laboratory of Cognitive and Adaptive Neuroscience; CNRS-UDS UMR 7364; Strasbourg France
| | | | - Astrid Nehlig
- Faculty of Medicine; INSERM U 666; Strasbourg France
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16
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Ahmad M. Protective effects of curcumin against lithium-pilocarpine induced status epilepticus, cognitive dysfunction and oxidative stress in young rats. Saudi J Biol Sci 2013; 20:155-62. [PMID: 23961231 PMCID: PMC3730552 DOI: 10.1016/j.sjbs.2013.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/31/2012] [Accepted: 01/01/2013] [Indexed: 10/27/2022] Open
Abstract
Status epilepticus (SE), one of the most severe forms of epilepsy is regarded a medical emergency with considerable morbidity and mortality. Due to the limited efficacy and enormous side effects of currently available drugs, a search for new safe and effective therapeutic agents is critical using experimentally induced SE in animals. The lithium-pilocarpine (Li-Pc) model of SE is most suitable and frequently used for pathophysiological and management strategies of SE. Recent studies have shown significant potential of pharmacological, prophylactic or therapeutic use of curcumin (Cur) in many beneficial activities in the body including neuroprotection in neurodegenerative diseases and antioxidant properties. The present study describes anticonvulsive effects of Cur in Li-Pc induced SE in young rats. The effect of Cur was examined on the intensity and frequency of SE, cognitive behavior in water maze as well as on oxidative stress related enzymes in the brain. Besides its anticonvulsant effect, Cur significantly ameliorates SE-induced cognitive dysfunction and oxidative damages in the hippocampus and striatum areas of the brain. Possible therapeutic application of Cur as an anticonvulsant and as an antioxidant for the treatment of SE has a great potential and warrants further studies.
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Affiliation(s)
- Mohammad Ahmad
- Department of Medical Surgical Nursing, College of Nursing, King Saud University, P.O. Box 642, Riyadh 11421, Saudi Arabia
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Karbowski LM, Parker GH, Persinger MA. Post-seizure drug treatment in young rats determines clear incremental losses of frontal cortical and hippocampal neurons: the resultant damage is similar to very old brains. Epilepsy Behav 2013; 27:18-21. [PMID: 23376334 DOI: 10.1016/j.yebeh.2012.12.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 12/17/2012] [Accepted: 12/19/2012] [Indexed: 11/20/2022]
Abstract
Loss of neurons occurs with aging and following lithium/pilocarpine-induced epileptic seizures. In the present study, the numbers of neurons within the layers from sample areas of the four lobes of the neocortices and the hippocampus were counted by light microscopy in brains of rats that had been administered lithium or pilocarpine and then injected immediately or shortly after seizure onset with either acepromazine, ketamine, or prazosin. The mean numbers of neocortical and hippocampal neurons were lowest in rats treated with acepromazine or prazosin 1h after seizure onset, while those of rats immediately treated with ketamine displayed the least decrements and were most similar to normal rats. The largest loss of neurons occurred within the CA1 field and layers 5 and 6 of the frontal cortices. The mean numbers of neurons within the cortices in rats whose treatments had been delayed for 1h were similar to those of normal rats over 700 days of age. These results support the hypothesis that neuronal loss from cumulative effects of seizure-induced brain damage simulates aging.
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Affiliation(s)
- Lukasz M Karbowski
- Department of Biology, Laurentian University, Sudbury, Ontario, Canada P3E 2C6
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18
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Aniol VA, Ivanova-Dyatlova AY, Keren O, Guekht AB, Sarne Y, Gulyaeva NV. A single pentylenetetrazole-induced clonic-tonic seizure episode is accompanied by a slowly developing cognitive decline in rats. Epilepsy Behav 2013; 26:196-202. [PMID: 23318024 DOI: 10.1016/j.yebeh.2012.12.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 11/04/2012] [Accepted: 12/08/2012] [Indexed: 12/13/2022]
Abstract
According to different studies, between 5% and 10% of people suffer a single isolated seizure episode at some time in their life. However, little is known about the effects of a single seizure episode on cognitive function, and clinical investigations of this issue are not easy to perform. In this situation, animal models may be a reasonable choice. The aim of our study was to follow the time course of delayed effects of generalized clonic-tonic convulsions on learning and memory functions in rats. A clonic-tonic seizure episode was induced by a single i.p. injection of pentylenetetrazole (70 mg/kg). Different behavioral tests were performed between days 10 and 100 after the convulsant administration. A single seizure episode resulted in a gradual decline in short-term memory function as assessed by novel object recognition and social recognition tests. The seizure episode induced a quick increase in hippocampal cell proliferation; however, the excessive newly generated cells seemed to be eliminated by the time of obvious cognitive impairment. These observations are indicative of a slowly developing and long-lasting influence of a single seizure episode on cognitive function. A rather long time period between the seizure episode and the manifestations of cognitive decline provides a window for a possible therapeutic intervention, and an elaboration of such "post-conditioning" treatments may be a promising opportunity to prevent subsequent mental impairments in patients.
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Affiliation(s)
- Victor A Aniol
- Department of Functional Biochemistry of the Nervous System, Institute of Higher Nervous Activity and Neurophysiology, RAS, Butlerov Street 5A, Moscow 117485, Russia
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Levin JR, Serrano G, Dingledine R. Reduction in delayed mortality and subtle improvement in retrograde memory performance in pilocarpine-treated mice with conditional neuronal deletion of cyclooxygenase-2 gene. Epilepsia 2012; 53:1411-20. [PMID: 22780884 DOI: 10.1111/j.1528-1167.2012.03584.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE Pilocarpine induces prolonged status epilepticus (SE) in rodents that results in neurodegeneration and cognitive deficits, both commonly observed to be associated with human temporal lobe epilepsy. The multifunctional neuronal modulator, cyclooxygenase-2 (PTGS2 or COX-2), is rapidly induced after SE, mainly in principal neurons of the hippocampal formation and cortex. We used mice in which COX-2 is conditionally ablated in principal forebrain neurons to investigate the involvement of neuron-derived COX-2 in delayed mortality and performance in the Barnes maze. METHODS Using the COX-2 conditional knockout mouse (nCOX-2 cKO) and their littermate wild-type controls, we compared motor behavior and performance in the Barnes maze before and 3 weeks after the induction of SE by pilocarpine. Mortality rate was also measured during SE and in the week following SE. KEY FINDINGS nCOX-2 cKO mice showed less delayed mortality than wild-type mice in the week after SE. Although motor behavior and most cognitive measures were not different in the nCOX-2 cKO, upon reexposure to the maze 3 weeks after pilocarpine, the latency to find the previously learned target hole was significantly shorter in the nCOX-2 cKO than their wild-type littermate controls. By this measure pilocarpine-treated nCOX-2 cKO mice were identical to mice that had not experienced SE. SIGNIFICANCE Results point to a role for neuronal COX-2 in delayed mortality in mice during the week following SE and suggest that neuronal COX-2 contributes to selected cognitive deficits observed after SE. Taking into consideration our previous findings that neurodegeneration and neuroinflammation after SE are reduced in the nCOX-2 cKO, and opening of the blood-brain barrier after pilocarpine is prevented, we conclude that neuronal COX-2 induction is an early step in many of the deleterious consequences of SE.
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Affiliation(s)
- Jamie R Levin
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, USA
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20
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Gorham R, Persinger MA. Emergence of complex partial epilepsy-like experiences following closed head injuries: personality variables and neuropsychological profiles. Epilepsy Behav 2012; 23:152-8. [PMID: 22206825 DOI: 10.1016/j.yebeh.2011.11.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 10/28/2011] [Accepted: 11/03/2011] [Indexed: 11/16/2022]
Abstract
To pursue Richard Roberts' epileptic spectrum disorder (ESD) and the emergence of complex partial epilepsy-like experiences, items and total scores for the ESD Inventory were examined for 185 patients who had sustained mechanical impacts (and were diagnosed with or without neuropsychological impairment) and a reference group (n=68) of university students. Results from neuropsychological, personality, neurological screening, and interview data supported the role of temporal lobe origins for these experiences. The incidences of these experiences were sufficient to adversely affect adaptation and to produce psychiatric profiles. Although only 70% of the patients who were impaired versus not impaired could be differentiated by items from the ESD Inventory, >95% of the patients with scores >100 on the ESD Inventory displayed abnormal scores on more than four Minnesota Multiphasic Personality Inventory scales. These results support Roberts' ESD concept and strongly suggest that persistent, subclinical occurrence of these experiences could be the cause or major correlate of neuropsychological impairment for these patients.
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Affiliation(s)
- Robyn Gorham
- School of Nursing, Laurentian University, Sudbury, ON, Canada
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21
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Fleming JL, Persinger MA, Koren SA. Magnetic Pulses Elevate Nociceptive Thresholds: Comparisons with Opiate Receptor Compounds in Normal and Seizure-Induced Brain-Damaged Rats. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/15368379409030699] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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22
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Bureau YRJ, Persinger MA. Decreased Incidence of Limbic Motor Seizures Following Twenty Pairings of Subclinical Lithium-Pilocarpine Injections and a Complex “Burst-Firing” Magnetic Field. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/15368379509028464] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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23
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Cook LL. Ventricular Enlargement and the Lithium/Pilocarpine Seizure Model: Possible Explanation for Agonistic Behaviour. Int J Neurosci 2009. [DOI: 10.3109/00207450008999682] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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24
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Martin LJ, Koren SA, Persinger MA. Thermal Analgesic Effects from Weak, Complex Magnetic Fields: Critical Parameters. Electromagn Biol Med 2009. [DOI: 10.1080/15368370500205399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Good LB, Sabesan S, Marsh ST, Tsakalis K, Treiman D, Iasemidis L. Control of synchronization of brain dynamics leads to control of epileptic seizures in rodents. Int J Neural Syst 2009; 19:173-96. [PMID: 19575507 PMCID: PMC3120842 DOI: 10.1142/s0129065709001951] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We have designed and implemented an automated, just-in-time stimulation, seizure control method using a seizure prediction method from nonlinear dynamics coupled with deep brain stimulation in the centromedial thalamic nuclei in epileptic rats. A comparison to periodic stimulation, with identical stimulation parameters, was also performed. The two schemes were compared in terms of their efficacy in control of seizures, as well as their effect on synchronization of brain dynamics. The automated just-in-time (JIT) stimulation showed reduction of seizure frequency and duration in 5 of the 6 rats, with significant reduction of seizure frequency (>50%) in 33% of the rats. This constituted a significant improvement over the efficacy of the periodic control scheme in the same animals. Actually, periodic stimulation showed an increase of seizure frequency in 50% of the rats, reduction of seizure frequency in 3 rats and significant reduction in 1 rat. Importantly, successful seizure control was highly correlated with desynchronization of brain dynamics. This study provides initial evidence for the use of closed-loop feedback control systems in epileptic seizures combining methods from seizure prediction and deep brain stimulation.
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Affiliation(s)
- Levi B. Good
- Harrington Department of Bioengineering, Arizona State University, Tempe, Arizona, USA, Department of Neurology Research, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, Arizona, USA
| | - Shivkumar Sabesan
- Department of Electrical Engineering, Arizona State University, Tempe, Arizona, USA
| | - Steven T. Marsh
- Department of Neurology Research, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, Arizona, USA
| | - Kostas Tsakalis
- Department of Electrical Engineering, Arizona State University, Tempe, Arizona, USA
| | - David Treiman
- Department of Neurology, St. Joseph's Hospital & Medical Center, Phoenix, Arizona, USA, Harrington Department of Bioengineering, Arizona State University, Tempe, Arizona, USA
| | - Leon Iasemidis
- Harrington Department of Bioengineering, Arizona State University, Tempe, Arizona, USA, , http://www.fulton.asu.edu
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26
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George KR, Rico T, St-Pierre LS, Dupont MJ, Blomme CG, Mazzuchin A, Stewart LS, Persinger MA, Persinger MA. Large differences in blood measures, tissue weights, and focal areas of damage 1 year after postseizure treatment with acepromazine or ketamine. Epilepsy Behav 2009; 15:98-105. [PMID: 19258049 DOI: 10.1016/j.yebeh.2009.02.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Revised: 02/23/2009] [Accepted: 02/26/2009] [Indexed: 10/21/2022]
Abstract
Approximately 1 year after rats were seized as young adults with lithium (3 mEq/kg) and pilocarpine (30 mg/kg) and given acepromazine or ketamine, 18 blood measures, wet tissue weights, and detailed damage scores for 107 brain structures were completed. Compared with normal and ketamine-treated rats, acepromazine-treated seized rats (total n=54) had lighter pancreata and spleens and elevated aspartate aminotransferase and alanine aminotransferase blood levels. Even though average damage did not differ, the mosaic of brain damage completely discriminated the two seized groups. Differential effects of postseizure treatment on functions of the thyroid, pancreas, and spleen were indicated. Ketamine-treated seized rats were healthier than acepromazine-treated seized rats or normal rats. This experiment demonstrates the importance of whole-organism assessment and that the single administration of a specific drug after onset of status epilepticus can produce marked differences in the evolution of brain damage and its influence on specific organs for the rest of the animal's life.
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Affiliation(s)
- Katherine R George
- Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
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Insidious weight gain in prepubertal seized rats treated with an atypical neuroleptic: the role of food consumption, fluid consumption, and spontaneous ambulatory activity. Epilepsy Behav 2009; 14:288-92. [PMID: 19110073 DOI: 10.1016/j.yebeh.2008.11.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 11/20/2008] [Accepted: 11/22/2008] [Indexed: 11/24/2022]
Abstract
Extreme obesity slowly develops in female rats over the months following seizures induced by a single systemic injection of lithium and pilocarpine if the resulting limbic seizures are treated with the atypical neuroleptic acepromazine (but not with ketamine). To discern the contributions from food consumption, water consumption, and (daytime and nighttime) activity to this weight gain, these behaviors were monitored for 4 months, about 2 months after seizure induction. The results indicated that the rats that underwent the obesity procedure exhibited 50% heavier body weights and consumed 42% more food than the reference group, which included rats that had been induced to seize but treated with ketamine. There were no statistically significant differences between groups with respect to either water consumption or (daytime or nighttime) activity. Factor analyses of data for individual rats verified the dissociation between activity and weight gain for the obese rats. The results suggest that the progressive weight gains are centrally mediated and are not secondary to diminished activity or altered fluid consumption.
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28
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Mach QH, Persinger MA. Behavioral changes with brief exposures to weak magnetic fields patterned to stimulate long-term potentiation. Brain Res 2009; 1261:45-53. [PMID: 19210956 DOI: 10.1016/j.brainres.2009.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 01/01/2009] [Accepted: 01/05/2009] [Indexed: 10/21/2022]
Abstract
Brief whole body exposures of rats to weak (1 microT) complex magnetic fields whose patterns induce long term potential (LTP) when applied as electric current to hippocampal slices produced powerful behavioral changes. Rats exposed for 30 min before but not 30 min after hourly training sessions for spatial memory displayed impairments comparable to those elicited by complete electrode-induced saturation of hippocampal activity. Exposure to the same LTP-patterned magnetic fields after weaning during the induction of limbic seizures produced diminished learning of conditioned contextual fear during adulthood. However exposure to magnetic fields designed to simulate a "virtual" hippocampal state during acquisition of a timed inhibitory task (DRL) facilitated performance. These results show that physiologically-patterned magnetic fields can produce dramatic changes in behavior when they are applied during states associated with marked synaptic plasticity.
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Affiliation(s)
- Quoc Hao Mach
- Behavioural Neuroscience Program, Laurentian University, Sudbury, Ontario, Canada
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29
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Pentoxifylline ameliorates lithium-pilocarpine induced status epilepticus in young rats. Epilepsy Behav 2008; 12:354-65. [PMID: 18203664 DOI: 10.1016/j.yebeh.2007.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 12/04/2007] [Accepted: 12/08/2007] [Indexed: 11/23/2022]
Abstract
The neuroprotective effects of pentoxifylline (PTX) against lithium-pilocarpine (Li-Pc)-induced status epilepticus (SE) in young rats are described. Animals treated with PTX (0, 20, 40, and 60 mg/kg) before induction of SE were examined for latency to and frequency of SE, behavioral changes, oxidative stress, neurochemical alterations in the hippocampus and striatum, and histological abnormalities in the hippocampus. Treatment with PTX significantly ameliorated the frequency and severity of epileptic seizures in a dose-dependent manner. Our behavioral studies using the elevated plus-maze, rotarod, and water maze tests suggested a significant reduction in anxiety, enhanced motor performance, and improved learning and memory in PTX-treated rats. Li-Pc-induced neuronal cell loss and sprouting of mossy fibers in the hippocampus were also attenuated by PTX. The neuroprotective activity of PTX was accompanied by reduction in oxidative stress and reversal of SE-induced depletion of dopamine and 5-hydroxytryptamine in hippocampus and striatum. The results of this study provide a good rationale to explore the prophylactic/therapeutic potential of PTX in SE.
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30
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Tetz LM, Rezk PE, Ratcliffe RH, Gordon RK, Steele KE, Nambiar MP. Development of a rat pilocarpine model of seizure/status epilepticus that mimics chemical warfare nerve agent exposure. Toxicol Ind Health 2006; 22:255-66. [PMID: 16924957 DOI: 10.1191/0748233706th268oa] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We developed a rat pilocarpine seizure/status epilepticus (SE) model, which closely resembles 1.6-2.0 x LD50 soman exposure, to analyse the molecular mechanism of neuronal damage and to screen effective neuroprotectants against cholinergic agonist and chemical warfare nerve agent (CWNA) exposure. Rats implanted with radiotelemetry probes capable of recording electroencephalogram (EEG), electrocardiogram (ECG), temperature, and physical activity were treated with lithium chloride (5 mEq/kg, im), followed 24 h later by (ip) doses of pilocarpine hydrochloride. Based on radiotelemetry analysis, a dose of 240 mg/kg (ip) pilocarpine generated seizure/SE analogous to 1.6-2.0 x LD50 of soman. The model was refined by reducing the peripheral convulsions without affecting the central nervous system (CNS) by administering methylscopolamine bromide (1 mg/kg, ip), an anti-cholinergic that does not cross the blood-brain barrier. However, when methylscopolamine bromide was administered, a higher dose of pilocarpine (320 mg/kg, ip) was required to generate the equivalent seizure/SE. Histopathology data indicated that pilocarpine induces significant damage to the hippocampal region of the brain, with similar neuropathology to that of 1.6-2.0 x LD50 soman exposure. There was a reduction in body temperature after the administration of pilocarpine, as observed in organophosphate (OP) nerve agents exposure. The heart-rate of pilocarpine-treated animals increased compared to the normal range. The pilocarpine seizure/SE model was also reproducible in the absence of lithium chloride. These results support that pilocarpine seizure/SE model is useful in studying the molecular mechanisms of neuropathology and screening neuroprotectants following cholinergic agonist and CWNA exposure.
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Affiliation(s)
- Lauren M Tetz
- Department of Biochemical Pharmacology/Division of Biochemistry, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910-7500, USA
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31
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Freitas RM, Oliveira ADA, Vasconcelos SMM, Sousa FCF, Viana GSB, Fonteles MMF. Expression of muscarinic and dopaminergic receptors and monoamine levels frontal cortex of epileptic rats. Pharmacol Biochem Behav 2006; 83:302-6. [PMID: 16563474 DOI: 10.1016/j.pbb.2006.02.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Revised: 01/21/2006] [Accepted: 02/11/2006] [Indexed: 11/21/2022]
Abstract
Apart from stroke, epilepsy is the most common neurological disorder with 0.5% of prevalence. The present study was performed in order to determine the monoamine levels, (M(1)-like) muscarinic and (D(1)- and D(2)-like) dopaminergic receptor changes in frontal cortex of adult rats after pilocarpine-induced status epilepticus (SE). Male Wistar rats were treated with a single dose of pilocarpine (400 mg/kg, s.c.) and the control group received 0.9% saline (s.c.). Both groups were sacrificed 1 h after treatment. The frontal cortex was dissected for neurochemical assays. The results show a downregulation of 27% in M(1) muscarinic receptor density, but in the dissociation constant (K(d)) value remained unaltered. D(1) and D(2) dopaminergic receptor densities and their K(d) values remained unaltered. Monoamine and metabolites levels presented decreases of 44%, 27%, 30% and 42% in dopamine (DA), homovanilic acid (HVA), norepinephrine (NE) and 5-hydroxyindoleacetic acid (5-HIAA) contents, respectively. Moreover, in serotonin (5-HT) level remained unaltered and the 4-hydroxy-3-methoxy-phenylacetic acid (DOPAC) concentration was augmented by 34%. The results suggest that dopaminergic system in this area studied may not be directly involved in the seizures and status epilepticus, but different monoamines and metabolites can be modified in this cerebral area during seizure process. In conclusion, the neurochemical alterations that occur in frontal cortex of adult rats observed during the establishment of the status epilepticus induced by pilocarpine are decrease in M(1) receptor density concentration and a reduction in DA and NE levels.
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Affiliation(s)
- Rivelilson M Freitas
- Department of Physiology and Pharmacology, Laboratory of Neuropharmacology, School of Medicine, Federal University of Ceara, Rua Cel. Nunes de Melo 1127, Fortaleza 60431-970, CE, Brazil.
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32
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McKay BE, Persinger MA. Weak, physiologically patterned magnetic fields do not affect maze performance in normal rats, but disrupt seized rats normalized with ketamine: possible support for a neuromatrix concept? Epilepsy Behav 2006; 8:137-44. [PMID: 16388988 DOI: 10.1016/j.yebeh.2005.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Revised: 10/11/2005] [Accepted: 11/13/2005] [Indexed: 11/30/2022]
Abstract
The concept of a neuromatrix as a determinant of behavior proposes that complex neuroelectromagnetic patterns supported by specific spatial configurations of neurons underlie the generation of behaviors. When the pattern of neuronal connectivity is changed, as occurs during limbic epilepsy, neuroelectromagnetic patterns change in parallel to sustain behavioral output. Thus, a testable prediction of the neuromatrix concept is that the "normal" behaviors of animals with markedly reorganized neuroelectromagnetic patterns are vulnerable to specific stimuli that are ineffective when applied to a normal population. Because rats treated with ketamine after being induced to seize with pilocarpine exhibit behaviors indistinguishable from those of control populations despite marked changes in brain structure, they represent an ideal population in which to examine this hypothesis. Ketamine-treated pilocarpine-seized rats and normal rats were exposed continuously either to a complex sequence magnetic field or to control conditions during the acquisition of a radial arm maze task for 8 consecutive days. After 14 days of subsequent exposure to a frequency-modulated field (7-500 nT), during which time there was no training, the rats that had been induced to seize and had been exposed continuously to this magnetic configuration exhibited conspicuously slower response durations per arm than rats that had been induced to seize and exposed to control conditions or normal rats that had been exposed to either magnetic fields or control conditions. Thus, the behaviors of rats who have sustained multiple, discrete injuries throughout the brain may be seriously disrupted by the appropriate pattern of exogenous weak magnetic fields. Our results represent the first empirical support for the concept of the neuromatrix.
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Affiliation(s)
- B E McKay
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ont., Canada P3E 2C6
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Mendes de Freitas R, Aguiar LMV, Vasconcelos SMM, Sousa FCF, Viana GSB, Fonteles MMF. Modifications in muscarinic, dopaminergic and serotonergic receptors concentrations in the hippocampus and striatum of epileptic rats. Life Sci 2005; 78:253-8. [PMID: 16137708 DOI: 10.1016/j.lfs.2005.04.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Accepted: 04/19/2005] [Indexed: 11/27/2022]
Abstract
The present study was undertaken in order to investigate the muscarinic (M(1)), dopaminergic (D(1) and D(2)) and serotonergic (5-HT(2)) receptors densities in hippocampus and striatum of Wistar rats after status epilepticus (SE) induced by pilocarpine. The control group was treated with 0.9% saline. An other group of rats received pilocarpine (400 mg/kg, s.c.) and both groups were sacrificed 1 h after treatment. The results have shown that pilocarpine administration and resulting SE produced a downregulation of M(1) receptor in hippocampus (41%) and striatum (51%) and an increase in the dissociation constant (K(d)) values in striatum (42%) alone. In both areas the 5-HT(2) receptor density remained unaltered, but a reduction (50%) and an increase (15%) in the K(d) values were detected in striatum and hippocampus, respectively. D(1) and D(2) receptor densities in hippocampus and striatum remained unaltered meanwhile K(d) values for D(1) receptor declined significantly, 33% in hippocampus and 26% in striatum. Similarly, K(d) values for D(2) decreased 55% in hippocampus and 52% in striatum. From the preceding results, it is clear that there is a possible relation between alterations in muscarinic receptor density and others systems studied as well as they suggest that changes in dissociation constant can be responsible for the establishment of pilocarpine-induced SE by altering the affinity of neurotransmitters such as acetylcholine, dopamine and serotonine.
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Affiliation(s)
- Rivelilson Mendes de Freitas
- Department of Physiology and Pharmacology, Laboratory of Neuropharmacology, School of Medicine, Federal University of Ceará, Rua Cel. Nunes de Melo 1127, Fortaleza 60431-970, CE, Brazil.
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Nascimento VS, Oliveira AA, Freitas RM, Sousa FCF, Vasconcelos SMM, Viana GSB, Fonteles MMF. Pilocarpine-induced status epilepticus: Monoamine level, muscarinic and dopaminergic receptors alterations in striatum of young rats. Neurosci Lett 2005; 383:165-70. [PMID: 15876489 DOI: 10.1016/j.neulet.2005.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2005] [Revised: 03/20/2005] [Accepted: 04/02/2005] [Indexed: 10/25/2022]
Abstract
Behavioural changes, muscarinic and dopaminergic receptors density and levels of monoamines were measured in striatum of rats after pilocarpine-induced status epilepticus (SE). Wistar rats at the age of 21 days were treated with pilocarpine (400mg/kg; subcutaneously) whilst the control group was treated with 0.9% saline (s.c.). Both groups were sacrificed 1h following the treatment. SE induced a muscarinic receptor downregulation of 64% in pilocarpine group. This effect was also observed to be 57% in D(1) and 32% in D(2). In the dissociation constant (K(d)) values in muscarinic and D(1) receptor no alterations were verified. On the other hand, the K(d) value for D(2) was observed to increase 41%. High performance liquid chromatography determinations showed 63, 35, 77 and 64% decreases in dopamine, 3-methoxy-phenylacetic acid, serotonin and 5-hydroxyindoleacetic acid contents, respectively. The homovanilic acid level was verified to increase 119%. The noradrenaline content was unaltered. A direct evidence of monoamine levels alterations can be verified during seizure activity and receptor density changes appear to occur in an accentuated way in immature brain during the estabilishment of SE induced by pilocarpine.
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Affiliation(s)
- V S Nascimento
- Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceara, Fortaleza, CE, Brazil
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Detour J, Schroeder H, Desor D, Nehlig A. A 5-month period of epilepsy impairs spatial memory, decreases anxiety, but spares object recognition in the lithium-pilocarpine model in adult rats. Epilepsia 2005; 46:499-508. [PMID: 15816943 DOI: 10.1111/j.0013-9580.2005.38704.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE In temporal lobe epilepsy (TLE), interictal behavioral disorders affect patients' quality of life. Therefore we studied long-term behavioral impairments in the lithium-pilocarpine (li-pilo) model of TLE. METHODS Eleven li-pilo adult rats exhibiting spontaneous recurrent seizures (SRSs) during 5 months were compared with 11 li-saline rats. Spatial working memory was tested in a radial arm maze (RAM), anxiety in an elevated plus-maze (EPM), and nonspatial working memory in an object-recognition paradigm. Neuronal loss was assessed on thionine brain sections after behavioral testing. RESULTS In the RAM, the time to complete each session and the number of errors per session decreased over a 5-day period in li-saline rats but remained constant and significantly higher in li-pilo rats. In the EPM, the number of entries in and time spent on open arms were significantly higher in li-pilo than li-saline rats. In the object-recognition task, the two groups exhibited a comparable novelty preference for the new object. Neuronal loss reached 47-90% in hilus, CA1, amygdala, and piriform and entorhinal cortex. CONCLUSIONS In li-pilo rats having experienced SRS for 5 months, performance in the object-recognition task is spared, which suggests that object discrimination remains relatively intact despite extensive damage. Neuronal loss in regions mediating memory and anxiety, such as hippocampus, entorhinal cortex, and amygdala, may relate to impaired spatial orientation and decreased anxiety.
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Affiliation(s)
- Julien Detour
- INSERM U398, Faculty of Medicine, Strasbourg, France.
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Persinger MA, McKay BE, O'Donovan CA, Koren SA. Sudden death in epileptic rats exposed to nocturnal magnetic fields that simulate the shape and the intensity of sudden changes in geomagnetic activity: an experiment in response to Schnabel, Beblo and May. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2005; 49:256-261. [PMID: 15726448 DOI: 10.1007/s00484-004-0234-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2003] [Revised: 07/09/2004] [Accepted: 10/01/2004] [Indexed: 05/24/2023]
Abstract
To test the hypothesis that sudden unexplained death (SUD) in some epileptic patients is related to geomagnetic activity we exposed rats in which limbic epilepsy had been induced to experimentally produced magnetic fields designed to simulate sudden storm commencements (SSCs). Prior studies with rats had shown that sudden death in groups of rats in which epilepsy had been induced months earlier was associated with the occurrence of SSCs and increased geomagnetic activity during the previous night. Schnabel et al. [(2000) Neurology 54:903-908] found no relationship between SUD in human patients and geomagnetic activity. A total of 96 rats were exposed to either 500, 50, 10-40 nT or sham (less than 10 nT) magnetic fields for 6 min every hour between midnight and 0800 hours (local time) for three successive nights. The shape of the complex, amplitude-modulated magnetic fields simulated the shape and structure of an average SSC. The rats were then seized with lithium and pilocarpine and the mortality was monitored. Whereas 10% of the rats that had been exposed to the sham field died within 24 h, 60% of the rats that had been exposed to the experimental magnetic fields simulating natural geomagnetic activity died (P<.001) during this period. These results suggest that correlational analyses between SUD in epileptic patients and increased geomagnetic activity can be simulated experimentally in epileptic rats and that potential mechanisms might be testable directly.
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Affiliation(s)
- M A Persinger
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
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Abstract
PURPOSE Seizures and antiepileptic drugs (AEDs) are the main causes for cognitive impairment in persons with epilepsy. It is still a matter of debate whether carbamazepine (CBZ) improves cognition because of its own psychotropic effects or because it is more effective to treat temporal epilepsy. Our objective was to analyze the performance of CBZ-treated or nontreated pilocarpine epileptic rats in an object-recognition test. METHODS Twelve chronic pilocarpine-induced epileptic rats were treated with CBZ, 40 mg/kg, or saline, t.i.d. for 8 days. Twenty-one nonepileptic controls were treated with CBZ or saline. On day 8 of treatment, all rats were tested with an object-recognition paradigm. RESULTS No locomotor impairment was detected in chronic epilepsy or CBZ treatment, as exploration during training was not affected. Exploratory behaviors during the choice session were not decreased in rats treated with CBZ; therefore CBZ does not compromise procedural memory. Epileptic rats showed a nonsignificant change in the discrimination performance, and prolonged treatment with CBZ in epileptic rats induced a significant increase in object discrimination during the choice session. CONCLUSIONS Even though pilocarpine-induced epileptic animals do not show compromised performance in the spontaneous object-recognition test, prolonged CBZ treatment has a positive effect on a simple object-discrimination task. These results may be associated with the psychotropic effects of CBZ.
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Affiliation(s)
- Rosane B Bernardi
- Division of Basic and Clinical Pharmacology, Department of Physiological Sciences, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, Brazil
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Freitas RM, Vasconcelos SMM, Souza FCF, Viana GSB, Fonteles MMF. Monoamine levels after pilocarpine-induced status epilepticus in hippocampus and frontal cortex of Wistar rats. Neurosci Lett 2004; 370:196-200. [PMID: 15488322 DOI: 10.1016/j.neulet.2004.08.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Revised: 08/09/2004] [Accepted: 08/11/2004] [Indexed: 11/20/2022]
Abstract
Pilocarpine-induced status epilepticus (SE) is an useful model to study the involvement of neurotransmitter systems as epileptogenesis modulators. Some researches have shown that pharmacological manipulations in dopaminergic, serotonergic, and noradrenergic systems alter the occurrence of pilocarpine-induced SE. The control group was treated with 0.9% saline (control group, s.c.). Another group of rats received pilocarpine (400mg/kg, s.c.) and both groups were sacrificed 24 h after the treatment. This work was performed to determine the alterations in monoamine levels (dopamine (DA), serotonin (5-HT) and norepinephrine (NE)) and their metabolites (3,4-hydroxyphenylacetic acid (DOPAC), homovanilic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA)) after pilocarpine-induced SE in hippocampus and frontal cortex of adult rats. The monoamines and their metabolites were determined by reverse-phase high-performance liquid chromatography with electrochemical detection. DA and 5-HIAA concentrations were not altered in the hippocampus of the pilocarpine group, but in the same group the 5-HT (160%), DOPAC (316%) and HVA (21%) levels increased, whereas, the NE (47%) content declined. For the frontal cortex determinations, there was an increase of 20 and 72% in DA and DOPAC levels, respectively, and a decrease in NE (32%), 5-HT (33%) and 5-HIAA (19%) concentrations, but HVA content remained unaltered. These results indicate that pilocarpine-induced SE can alter monoamine levels in different ways depending on the brain area studied, suggesting that different mechanisms are involved.
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Affiliation(s)
- R M Freitas
- Laboratory of Neuropharmacology, Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceará, Rua Cel. Nunes de Melo 1127, Fortaleza 60431-970, CE, Brazil.
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Persinger MA, Dupont MJ. Emergence of spontaneous seizures during the year following lithium/pilocarpine-induced epilepsy and neuronal loss within the right temporal cortices. Epilepsy Behav 2004; 5:440-5. [PMID: 15256179 DOI: 10.1016/j.yebeh.2004.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2003] [Revised: 03/22/2004] [Accepted: 03/23/2004] [Indexed: 11/22/2022]
Abstract
Thirty days after the induction of seizures in 16 rats with lithium (3 mEq/kg) and pilocarpine (30 mg/kg), the numbers of episodes of motor seizures (rapid forelimb clonus) during daily 10-minute observational periods were recorded for 11 months. The proportions of neuronal loss were ranked using two methods by light microscopy for all structures between the posterior and anterior commissures. Amounts of damage within the dentate gyrus, hilus (CA4), and CA3 field were most strongly correlated with numbers of seizures per month about 6 months before the brains were removed. The strongest correlations occurred between the amounts of damage within the right temporal cortices, even after the variance associated with damage within the dentate gyrus had been removed, and the numbers of seizures during the last 2 months. These results may explain the greater proportion of spontaneous seizures that begin with left side forelimb clonus and suggest a particular sensitivity of the right side of the brain to either their initiation or their consequences.
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Affiliation(s)
- M A Persinger
- Behavioral Neuroscience Program, Laurentian University, Sudbury Ont., Canada, P3E 2C6.
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McKay BE, Persinger MA. Normal spatial and contextual learning for ketamine-treated rats in the pilocarpine epilepsy model. Pharmacol Biochem Behav 2004; 78:111-9. [PMID: 15159140 DOI: 10.1016/j.pbb.2004.02.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2003] [Revised: 12/05/2003] [Accepted: 02/27/2004] [Indexed: 11/18/2022]
Abstract
Cognitive impairments frequently accompany epileptic disorders. Here, we examine two neuroprotective agents, the noncompetitive NMDA antagonist ketamine and the dopaminergic antagonist acepromazine, for their efficacy in attenuating cognitive impairments in the lithium-pilocarpine (LI-PILO) model of rat limbic epilepsy. Declarative-like cognitive behaviors were assessed in a Morris water maze task that consisted successively of spatial and nonspatial (cued platform) training. Whereas the ketamine-treated (Ket) LI-PILO rats performed equally in all respects to nonseized control rats for the spatial and nonspatial components of the water maze task, the acepromazine-treated (Ace) LI-PILO rats failed to demonstrate learning in either the hidden or cued platform variants of the task and did not demonstrate any place learning in the platform-removed probe trials. We further assessed nondeclarative (associative) cognitive behaviors with a standard contextual fear-conditioning protocol. LI-PILO rats treated with acepromazine failed to learn the Pavlovian relationship; Ket LI-PILO rats performed equivalently to nonseized controls. Cumulatively, these data suggest robust cognitive sparing for LI-PILO rats with pharmacological NMDA receptor antagonism following induction of status epilepticus (SE). This cognitive sparing occurs despite earlier findings that the mean amount of total brain damage with LI-PILO is equivalent for Ket and Ace rats.
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Affiliation(s)
- B E McKay
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ontario, Canada P3E 2C6.
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de Freitas RM, de Sousa FCF, Vasconcelos SMM, Viana GSB, Fonteles MMDF. [Acute alterations of neurotransmitters levels in striatum of young rat after pilocarpine-induced status epilepticus]. ARQUIVOS DE NEURO-PSIQUIATRIA 2003; 61:430-3. [PMID: 12894279 DOI: 10.1590/s0004-282x2003000300019] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High doses of the muscarinic cholinergic agonist, pilocarpine, result in behavioural changes, seizures and status epilepticus in rats. The purpose of the present work is to invetigate the striatal neurotransmissors level in young rats after status epilepticus induced by pilocarpine. Wistar rats were treated with a single dose of pilocarpine (400mg/Kg; s.c.). Controls received saline. Young animals were closed observed for behavioural changes during 1 and 24h. In these periods, the animals that developed status epilepticus and didn't survive this acute phase of seizures had the brains removed and striatal neurotransmissors level determined by HPLC. The concentration of dopamine, serotonine, dihydroxyphenylacetic acid, 5-hydroxyindolacetic acid was reduced and an increase in 4-hydroxy-3-methoxy-phenylacetic acid was observed. These results suggest that cholinergic activation can interage with dopaminergic and serotonergic systems in acute phase of the convulsive process in immature striatum.
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Persinger MA. Rats' preferences for an analgesic compared to water: an alternative to "killing the rat so it does not suffer". Percept Mot Skills 2003; 96:674-80. [PMID: 12776852 DOI: 10.2466/pms.2003.96.2.674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A common policy in research institutions is to kill rats when they display chronic disabilities or recurrent injuries. These guidelines appear to be derived from an oxymoron that "it's better for a rat to be killed so it does not suffer pain" and from untested assumptions that rats cannot control "pain." In a two-bottle paradigm, 10 rats with a history of brain damage following status epilepticus from a single systemic injection of lithium and pilocarpine were given options to consume freely either tap water or 1 mg/cc of acetaminophen in tap water. During periods of fresh lesions due to persistent gnawing or acute injuries associated with tonic-clonic convulsions, the rats consumed 3 to 10 times the fluid from the bottles containing acetaminophen (equivalent to 5 to 10 extra-strength Tylenol tablets per day for a 70-kg person) relative to periods when no lesions or old lesions were present. These results suggest that rats with chronic injuries sufficient to be terminated according to Animal Care guidelines may be capable of reducing the aversive physiological conditions associated with tissue damage by selecting analgesic treatments.
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Affiliation(s)
- M A Persinger
- Department of Psychology, Laurentian University, Sudbury, ON, Canada
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Kinoshameg SE, Persinger MA. Working memory and reference memory in adult rats following limbic seizures induced at 21 or 90 days of age. Psychol Rep 2002; 91:729-30. [PMID: 12530715 DOI: 10.2466/pr0.2002.91.3.729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Rats were either seized or not seized at 21 days of age (weaning) or at 90 days of age with a single systemic injection of lithium (3 mEq/kg) and pilocarpine (30 mg/kg). When tested as adults (120 days of age) for spatial memory in the Olton radial maze, the rats that had been seized as adults exhibited about five times more working (short-term) memory errors than the other three groups which did not differ significantly from one another. The numbers of errors for long-term (reference) memory did not differ significantly among the four groups. The deficits in working memory for the group seized as weanlings and reported previously were not replicated. One possible explanation for this discrepancy might be differential effects upon brain organization associated with seizures evoked by injecting the pilocarpine 24 hr. rather than 4 hr. after the lithium.
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KINOSHAMEG SE. WORKING MEMORY AND REFERENCE MEMORY IN ADULT RATS FOLLOWING LIMBIC SEIZURES INDUCED AT 21 OR 90 DAYS OF AGE. Psychol Rep 2002. [DOI: 10.2466/pr0.91.7.729-730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Persinger MA, Stewart LS, Richards PM, Harrigan T, O'Connor RP, Bureau YRJ. Seizure onset times for rats receiving systemic lithium and pilocarpine: sources of variability. Pharmacol Biochem Behav 2002; 71:7-17. [PMID: 11812503 DOI: 10.1016/s0091-3057(01)00583-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Injection of 30 mg/kg of pilocarpine 24 h after systemic injection of lithium (3 mEq/kg) results in overt limbic motor seizures within about 30 min. Results of several experiments indicated that whereas food deprivation or repeated nociceptive stimulation during the previous 24 h decreased seizure onset times (SOTs) by about 11 to 12 min, food restriction, continuous lighting, or, handling during the previous 7 to 14 days increased SOTs by comparable durations. Early handling before weaning but not injections of clomimpramine also decreased SOTs. A difference of 18 min in the means of SOTs was produced by injecting either 1.0 (increased SOT) or 1.5 mg/kg (decreased SOT) of dexamethasome during the previous 24 h. A strong (multiple r=.87) association between SOTs and the amount of damage within five specific thalamic-limbic nuclei was observed. These results, in conjunction with blood corticosterone levels taken before and after induction of the seizures, suggest the neurochemical mechanisms affecting the range in SOTs could involve the adrenocorticotropic hormone (ACTH)-corticosterone system and influence the amount of post-seizure-induced damage.
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Affiliation(s)
- M A Persinger
- Behavioral Neuroscience Laboratory, Department of Psychology, Laurentian University, Sudbury, Ontario, Canada P3E 2C6.
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Stewart LS, Persinger MA. Ketamine Prevents Learning Impairment When Administered Immediately after Status Epilepticus Onset. Epilepsy Behav 2001; 2:585-591. [PMID: 12609394 DOI: 10.1006/ebeh.2001.0272] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Permanent cognitive impairment is common following status epilepticus (SE) in both humans and animals. We examined the effect of the NMDA antagonist ketamine administered after SE onset on two forms of associative learning in the rat: conditioned taste aversion and fear-conditioned analgesia. Following the onset of lithium/pilocarpine-induced SE, rats were administered either ketamine (100 mg/kg) or acepromazine (25 mg/kg). Acepromazine-treated animals show marked deficits in both learning measures at 1 month after SE. In contrast, ketamine-treated and nonepileptic control animals did not differ in performance for either task. Although studies have shown that ketamine is ineffective at controlling electrographic seizures early in SE, these results are consistent with previous studies showing that ketamine can preserve learning proficiency if administered shortly after seizure onset. As a clinically available drug, ketamine may prove useful in the treatment of SE when combined with conventional antiepileptic strategies.
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Affiliation(s)
- Lee S. Stewart
- Behavioral Neuroscience Program, Department of Biology, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada
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Persinger MA, O'Connor RP, Bureau YR, Parker GH, Peredery O, Zegil M. Synergistic induction of severe hypothermia (poikilothermia) by limbic seizures, acepromazine and physical restraint: role of noradrenergic alpha-1 receptors. Pharmacol Biochem Behav 2001; 70:341-52. [PMID: 11701206 DOI: 10.1016/s0091-3057(01)00619-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The maintained production of extreme reductions in core temperature (20-22 degrees C) or poikilothermia can be reliably produced by the synergistic interaction of limbic seizures (induced by lithium and pilocarpine), postseizure administration of a single injection of acepromazine, and physical restraint. Administration of the specific and nonspecific dopamine antagonists haloperidol, chlorpromazine, SCH23390, or clozapine did not simulate the effect at clinically effective dosages. Single injections of phentolamine and prazosin but not of propranolol instead of acepromazine following the seizures produced the poikilothermia. This effect was also reproduced by reducing the amount of the rats' adipose weight before the induction of the seizures and physical restraint. Rats that had been restrained or not restrained and displayed either euthermia or hypothermia exhibited significantly different patterns in brain damage within limbic and thalamic structures.
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Affiliation(s)
- M A Persinger
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ontario, Canada P3E 2C6.
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Glien M, Brandt C, Potschka H, Voigt H, Ebert U, Löscher W. Repeated low-dose treatment of rats with pilocarpine: low mortality but high proportion of rats developing epilepsy. Epilepsy Res 2001; 46:111-9. [PMID: 11463512 DOI: 10.1016/s0920-1211(01)00272-8] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Systemic administration of pilocarpine in rats can result in a chronic behavioral state that is similar to human temporal lobe epilepsy. The pilocarpine model of epilepsy is widely used for studying the factors that contribute to the development of epilepsy as a consequence of status epilepticus (SE). For this purpose, pilocarpine is either administered alone at a high systemic dose or in combination with lithium, which markedly potentiates the convulsant effect of pilocarpine. Both experimental protocols, however, are associated with high mortality rates. In the present study, we evaluated whether mortality rate in rats can be decreased by repeated administration of low doses of pilocarpine. The time the rats spent in SE was limited by diazepam. Preliminary experiments in lithium-free rats indicated that repeated low-dose administration of pilocarpine is too time-consuming to produce SE compared to single high-dose administration. All subsequent experiments were performed in lithium-pretreated rats. Single-dose injection of 30 mg/kg pilocarpine produced SE in approximately 70% of the animals, but 45% of the rats died although SE was interrupted by diazepam after 90 min. Repeated i.p. administration of 10 mg/kg pilocarpine at 30-min intervals resulted in SE after 2-4 injections; the mean dose of pilocarpine needed to induce SE was 26 mg/kg. When SE was interrupted after 90 min, mortality rate was below 10%, which was significantly lower compared to the protocol with one single administration of 30 mg/kg pilocarpine. In contrast to mortality rate, the development of spontaneous recurrent seizures did not differ between experimental protocols. Almost all rats which had experienced a SE of at least 60 min developed chronic epilepsy. Average latency to the first spontaneous seizure was approximately 40 days. The frequency and severity of spontaneous seizures was not significantly different between protocols, although animal groups with repeated low-dose treatment tended to have higher frequencies of spontaneous seizures compared to single-dose administration. The present study demonstrates that systemic treatment of lithium-pretreated rats with several low doses of pilocarpine efficiently produces SE and chronic epilepsy with much lower mortality rates than single-dose pilocarpine.
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Affiliation(s)
- M Glien
- Department of Pharmacology, Toxicology and Pharmacy, School of Veterinary Medicine, Bünteweg 17, D-30559 Hannover, Germany
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Jedrzejko C, Persinger MA. Weight gain in post-seized rats is facilitated by adding aspirin, glucose, or glucose-taurine-acetaminophen to food mush. Psychol Rep 2001; 89:188-90. [PMID: 11729541 DOI: 10.2466/pr0.2001.89.1.188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Adult male rats were seized with lithium and pilocarpine and administered acepromazine to facilitate survival. After four days (1) 8 mg of acetylsalicylic acid (aspirin), (2) 100 mg taurine-15 mg acetaminophen (Tylenol)-40 mg glucose, (3) 40 mg glucose, or (4) water was added to the food mush daily for 30 days. A fifth group served as non-seized controls. Within one week all pharmacological treatments promoted more weight recovery than food mush only. The rats receiving aspirin (equivalent to 3 tablets/day for humans) showed the greatest early recovery. After 15 days of treatment the pharmacologically treated seized rats had returned to baseline weight and did not differ from normals whereas seized rats given only food mush had not. We suggest inhibiting prostaglandins by anti-inflammatory compounds or stimulating the GABA shunt pathway through enhanced dietary glucose to accelerate weight gain following the significant loss that accompanies brain injury.
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Desjardins D, Parker G, Cook LL, Persinger MA. Agonistic behavior in groups of limbic epileptic male rats: pattern of brain damage and moderating effects from normal rats. Brain Res 2001; 905:26-33. [PMID: 11423076 DOI: 10.1016/s0006-8993(01)02454-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Different ratios of normal male rats and male rats in which limbic seizures had been induced by a single systemic injection of lithium and pilocarpine were housed in groups of six. The group ratios ranged along the continuum from all normal rats to all experimental rats. The average numbers of episodes of boxing, biting and mounting--thrusting per rat per hour per group were recorded by direct observation (red light) for 1 h during the midscotophase. Groups that contained less than two normal rats exhibited significantly elevated amounts of agonistic (boxing, biting) behavior but not mounting behavior. Multiple regression analyses showed that combinations of neuronal loss within only two to three areas accommodated at least 50% of the variance in the numbers of these behaviors.
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Affiliation(s)
- D Desjardins
- Behavioral Neuroscience Program, Department of Biology, Laurentian University, Sudbury, Ontario, Canada P3E 2C6
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