Alterations in acetylcholine-induced stimulation of inositol phospholipid hydrolysis in the dorsal hippocampus of kindled rats.

Agonist-induced turnover or release of inositolphosphates (IP) was studied in the dorsal and the ventral hippocampus 24 h, 1 month, and 3 months after the last electrical stimulus of kindled rats. A significant increase in acetylcholine (ACh)-stimulated IP turnover was observed in dorsal, but not ventral, hippocampus 24 h and 1 month after the last electrical stimulus. However, this effect was not evident 3 months after kindling. The excitatory amino acids (quisqualic acid and ibotenic acid) at the concentrations used, however, failed to produce any change in receptor-stimulated release or turnover of IP. Thus the changes in ACh-induced IP release, although long-term, are not permanent and do not appear to be released to the neurobiological alterations associated with the long-term maintenance of the kindling phenomenon.