The hippocampus as a determinant structure generating epileptic activity during metrazol kindling

Крыжановский, Г. Н.; Шандра, А. А.; Makul'kin, R. F.; Godlevskii, L. S.

doi:10.1007/bf00837263

Cited by 6 publications

(5 citation statements)

References 7 publications

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“…Therefore, in this case epileptogenesis is also moderated. It agrees with our findings [4] that damage to hippocalnpus retards the development of enhanced cerebral seizure readiness during corazol-induced kindling.…”

Section: Resultssupporting

confidence: 94%

Effect of cerebral ischemia on acute convulsions and chronic epileptogenesis

1998

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The pharmacological kindling with corazol was used as a model of chronic cerebral epileptization. In contrast to sham-operated rats or rats with unilateral occlusion of the common carotid arteries, bilateral occlusion of these vessels moderated acute seizures provoked by a single administration of the convulsant corazol and abated the enhanced cerebral seizure readiness induced by its repeated administration.Key Words: epileptogenesis; pharmacological kindling; enhanced cerebral seizure readiness; acute convulsions; cerebral ischemia Epilepsy and cerebral ischemia are the manifestations of pathological condition in the central nervous system. The problem of their interference is of great theoretical and practical interest. Our aim was to study the role of cerebral ischemia in epileptogenesis and, in particular, the effect of ischemia caused by uni-and bilateral occlusion of common carotid arteries (CCA) on acute convulsions and chronic epileptogenesis characterized by enhanced cerebral seizure readiness (pharmacological kindling). MATERIALS AND METHODSExperiments were carried out on 200 male Wistar rats (initial body weight 270-300 g). The animals were maintained under vivarium conditions on the standard diet. Cerebral ischemia was produced by occlusion of the left or both CCA under hexenal anesthesia (150 mg/kg intraperitoneally). The control group consisted of sham-operated rats.In the first series of experiments we studied the effect of cerebral ischemia of various severity on acute convulsions provoked by intraperitoneal adLaboratory of Biochemistry, Laboratory of General Pathology of the Nervous System, Institute of General Pathology and Pathological Physiology, Russian Academy of Medical Sciences, Moscow ministration of corazol in the doses of 40 and 65 mg/kg. The second series related to the effect of cerebral ischemia on the development of enhanced cerebral seizure readiness elicited by diurnal intraperitoneal administration of corazol in a subconvulsive dose of 25-35 mg/kg for 30-70 days (the model of corazol-induced kindling). This intervention produced a gradual increase in cerebral seizure readiness to the action of the convulsant, which was manifested in the fact that seizures in the treated rats were elicited by subconvulsive doses of corazol, while the severity of these seizures increased during the treatment and cuhninated in a generalized clonic-tonic seizure. Rats with a similar corazol sensitivity were sorted out after a single administration of corazol in the minimal effective dose [2]. In both series corazol was administered one week after uni-or bilateral CCA occlusion.The severity of corazol-produced convulsive response during kindling was evaluated daily using a scoring system in which score 1 was assigned to momentary shuddering and nodding; score 2 to discrete clonic convulsions of the whole body; score 3 to a series of clonic convulsions of the whole body or to clonus of the forelimbs; score 4 to tonic-clonic convulsions with rearing up on the hind legs ("kangaroo" posture); and, score ...

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Section: Resultssupporting

confidence: 94%

Effect of cerebral ischemia on acute convulsions and chronic epileptogenesis

1998

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“…Experimental rats were injected daily with intraperitoneal picrotoxin (Fluka) in a subconvulsant dose of 1.5 mg/kg. The development of seizures was visually assessed in points [4]. After 21 injections the convulsive activity manifested itself in recurrent clonic seizures (3 points).…”

Section: Methodsmentioning

confidence: 99%

“…This phenomenon is considered to be the most adequate model of epileptogenesis [4,5]. Kindling induces persistent structural and functional changes in some brain regions, in particular in the hippocampus [9], which can result in learning and memory disorders.…”

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confidence: 99%

Memory impairment after incomplete pharmacological kindling

Архипов

Сочивко

1999

Bull Exp Biol Med

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In rats trained to run for food reinforcement, kindling was reproduced by daily injections of subconvulsant doses of picrotoxin until the stage of recurrent clonic seizures. Subsequent behavioral test revealed no difference between kindled and control rats in retention and retrieval of memory traces. However these groups differed significantly in the dynamics and pattern of extinction: kindled animals needed much more time to stop running under conditions of non-reinforcement. A relearning test showed that kindling did not affect learning ability. Weakened inhibition after incomplete pharmacological kindling is indicative of a congnitive dysfunction characteristic of early stages of epilepsy.

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“…Convulsant activity was assessed as described previously [5] by the latency of grade I-II and Ill-IV seizures and animals death. LDs0 was calculated using the method of probit-analysis.…”

Section: Methodsmentioning

confidence: 99%