Increase in striatal acetylcholine levels by GABAergic agents: dependence on corticostriatal neurons.

Surgical lesion of the corticostriatal projections almost totally reduced the ability of GABA agonist agents but not apomorphine to increase rat striatal ACh concentrations. This suggests that in intact rats, the GABAergic inhibition of striatal cholinergic neurons depends, at least in part, upon the corticostriatal (possibly glutamatergic) tract whereas the action of the dopaminergic pathway on cholinergic cells is independent of corticostriatal neurons.