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

Abstract

Bath application of glutamate at two concentration ranges, 10 −6 – 10 −8 and 1 – 3 × 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 × 10 −3 M further suggests that release of adenosine is a link from enhanced cyclic GMP activity to activation of acetylcholinesterase.