Fig. 3. Inhibition of spontaneous firing by activation of GABA_A or GABA_B receptors.

(A) Typical firing traces recorded from acutely dissociated DA neurons. Isoguvacine (20 µM) and (R)-Baclofen (100 µM) applications completely inhibited spontaneous firing activity of DA neurons. (B) Effects of GABA_A agonist and GABA_B agonist on spontaneous firing are summarized (n=9). (C) GABA induced firing inhibitions in the presence of CGP55845 (2 µM) or SR95531 (5 µM). (D) CGP55845 (2 µM) and SR95531 (5 µM) did not alter the effect of GABA (n=5). ^**p<0.01 by two sample t-test.