Effects of GABAmimetics on electrocorticographic spike discharges induced by guanidinoethanesulfonic acid (amidino-taurine) in the rat.

Article date: 1993/4/1

PubMed ID: 1724553

Journal name: Neurochemical research (ISSN: 0364-3190)


The effect of guanidinoethanesulfonic acid (GES) on rat electrocorticograms (ECoG) and the effects of gamma-aminobutyric acid (GABA) and GABA-agonists on the ECoG changes induced by GES were studied. Sporadic spike discharges began 2-5 min after 1 mumol GES/10 microliters on filter paper was applied to the pia mater of the left sensorimotor cortex; spike discharges extended to the opposite cerebral hemisphere 60 min after the onset of the ipsilateral spike discharges. The spike discharges with a frequency of 5-10 spikes/min lasted until the end of the 4 hour recording. The induced spike discharges were suppressed when the original GES soaked filter paper was replaced by one containing GES (1 mumol) supplement combined with taurine (1 mumol/10 microliters). GABA (1 mumol) and its receptor agonist, muscimol (10 nmol) and (3R)-(-)-4-amino-3-hydroxybutyric acid (1 mumol) also suppressed the GES-induced spike discharges when applied topically. Diazepam (DZP) (10 mg/kg) suppressed the GES-induced spike discharges 10 min after i.p. injection, but phenobarbital (20 mg/kg) increased the frequency and voltage of spike discharges 100 min following subcutaneous administration. Intraperitoneal injection of either valproate (200 mg/kg) or phenytoin (25 mg/kg), after the completion of the spike discharges, showed no effect. These findings suggest that neurotransmission or neuromodulatory effects of taurine participate in GES-induced seizure activity, and that GABAA and DZP receptors may play a role in the mechanism that suppresses GES-induced seizures.

Author List: Yokoi I, Kabuto H, Mori A

Publication Types: Journal Article

Substances mentioned in the article: Taurine; Muscimol; taurocyamine; gamma-Aminobutyric Acid; Diazepam;

Mesh terms: Action Potentials/drug effects; Animals; Cerebral Cortex/drug effects; Diazepam/pharmacology; Electroencephalography; Male; Muscimol/pharmacology; Rats; Rats, Sprague-Dawley; Taurine/analogs & derivatives; gamma-Aminobutyric Acid/pharmacology;

Citations: - Use of 3H-muscimol for GABA receptor studies.

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