Hippocampal kindling enhances excitatory amino acid receptor-mediated polyphosphoinositide hydrolysis in the hippocampus and amygdala/pyriform cortex.

Article date: 1989/6/19

PubMed ID: 2547498

Journal name: Brain research (ISSN: 0006-8993)


We recently demonstrated that a long-lasting increase in ibotenate-stimulated polyphosphoinositide (PPI) hydrolysis in the amygdala/pyriform cortex (AM/PC) is associated with seizure susceptibility of amygdala (AM)-kindled rats. The present study examined (1) whether ibotenate-stimulated PPI hydrolysis would be lastingly enhanced in the hippocampus (HIPP) and AM/PC of the HIPP-kindled rats and (2) whether similar changes would be found in the early stage of HIPP kindling. Although ibotenate-stimulated accumulation of [3H]inositol 1-phosphate ([ 3H]IP1) increased significantly in the HIPP 24 h, 5 days, and 15 days after the last seizure of fully developed HIPP-kindled rats, no statistically significant increase was found in the HIPP 30 days after the last seizure. In the AM/PC, 10(-3) M ibotenate-stimulated [3H]IP1 accumulation significantly increased by 91%, 91%, 86% and 90%, 24 h, 5 days, 15 days and 30 days after the last seizure, respectively. There was no significant increase in ibotenate-stimulated [3H]IP1 accumulation 7 days after the last stimulation in the HIPP and AM/PC of rats which had undergone electrical stimulation only 5 times in the HIPP. These results indicate that (1) PPI hydrolysis coupled to excitatory amino acid receptors increases long-lastingly in the AM/PC regardless of the primary kindled site, and (2) these changes do not occur in the early stage of HIPP-kindling.

Author List: Yamada N, Akiyama K, Otsuki S

Publication Types: Journal Article; Research Support, Non-U.S. Gov't

Substances mentioned in the article: Oxazoles; Phosphatidylinositols; Receptors, Amino Acid; Receptors, Cell Surface; Ibotenic Acid;

Mesh terms: Amygdala/metabolism; Animals; Cerebral Cortex/metabolism; Hippocampus/drug effects; Ibotenic Acid/pharmacology; Kindling, Neurologic; Male; Oxazoles/pharmacology; Phosphatidylinositols/metabolism; Rats; Rats, Inbred Strains; Receptors, Amino Acid; Receptors, Cell Surface/drug effects; Time Factors;

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