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Cholinergic Mechanisms in Generalized Seizures: Importance of the Zona Incerta

Published online by Cambridge University Press:  18 September 2015

Stefan M. Brudzynski ,
James W. Cruickshank  and
Richard S. McLachlan
Stefan M. Brudzynski*
Affiliation:
Department of Clinical Neurological Sciences, University of Western Ontario, and Epilepsy Research Laboratory, University Hospital, London
James W. Cruickshank
Affiliation:
Department of Clinical Neurological Sciences, University of Western Ontario, and Epilepsy Research Laboratory, University Hospital, London
Richard S. McLachlan
Affiliation:
Department of Clinical Neurological Sciences, University of Western Ontario, and Epilepsy Research Laboratory, University Hospital, London
*
Department of Clinical Neurological Sciences, University Hospital, P.O. Box 5339, Postal Stn. A, London, Ontario, Canada N6A 5A5
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Abstract

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Objective:

Stimulation of the central cholinergic system results in generalized epileptic seizures. The goal of this study was to map the epileptogenic effects of the cholinergic agonist, carbachol injected into different sites of the basal forebrain and diencephalon of the rat brain.

Methods:

Carbachol was injected directly into the brain in a dose of 1 or 3 (jg. Seizures were assessed behaviourally on a five-stage scale with electroencephalographic controls. Seizures at stage 1 were the least severe and those at stage 5 the most severe.

Results:

Injections of high dose carbachol (3 (jg) induced seizures from 40% of all injected brain sites. Injections of low dose carbachol (1 ug) or isotonic saline into the same brain sites did not cause any behavioural or electrographic seizures. The majority of sites (84%) producing generalized seizures (stage 5) were concentrated in or around the zona incerta.

Conclusions:

Within the anatomical limits of the study, the zona incerta is the area most sensitive to carbachol-induced generalized seizures.

Type
Original Articles
Information
Canadian Journal of Neurological Sciences , Volume 22 , Issue 2 , May 1995 , pp. 116 - 120
Copyright
Copyright © Canadian Neurological Sciences Federation 1995

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