Glutamate-elicited stimulation of acetylcholinesterase activity in cerebellar slices from newborn rats.

Bath application of glutamate at two concentration ranges, 10(-6)-10(-8) and 1-3 X 10(-3) M, effectively increased acetylcholinesterase activity in cerebellar slices obtained from 8-day-old rats. No such effect was seen in cerebellar slices of 7-week-old rats or cerebral slices of either 7-week or 8-day-old rats. Glutamic acid diethyl ester blocked the glutamate effect at both of these concentration ranges, suggesting that quisqualate-sensitive glutamate receptors are involved in regulation of acetylcholinesterase activity in early postnatal cerebellum. Since bath application of cyclic GMP at 10(-7)-10(-9) M increased the acetylcholinesterase activity in cerebellar slices of 8-day-old rats, it is possible that glutamate-dependent regulation of acetylcholinesterase activity is mediated by cyclic GMP. The observation that adenosine deaminase blocked the effect of glutamate completely at 10(-6)-10(-8) M and partially at 1-5 X 10(-3) M further suggests that release of adenosine is a link from enhanced cyclic GMP activity to activation of acetylcholinesterase.