Jaen et al. and by their ability to reverse the y-butyrolactone (GBL) induced increase in the rate of dihydroxyphenylalanine (DOPA) synthesis (an indirect measure of the rate of DA synthesis) in the rat corpus striatum, a major brain DA projection area. 13 Inhibition of exploratory locomotor activity in mice and rats was used as a behavioral index of DA autoreceptor acti~ ation'~ and/or postsynaptic DA antag0ni~ ml~ As part of this test, ...