Gamma-aminobutyric acid and bicuculline effects on acetylcholine metabolism in the striatum in rats.

Gamma-aminobutyric acid (GABA) injected into the lateral ventricles of rat bran in a dose of 600 microgram raised the level and increased the synthesis of acetylcholine (ACh) raising also the activity of choline acetyltransferase (ChAc) but had no effect on the activity of cholinesterase (AChE) in rat striatum. Bucuculline (Bk) in doses of 10 mirogram i.c.v reduced ACh synthesis and in 50 and 10 microgram doses reduced the activity of ChAc. No Bk effect on AChE activity was demonstrated. The observed effects of GABA were abolished by pretreatment with Bk in doses of 1, 5 or 10 microgram.