Fig. 3.

Dopamine inhibits GABAergic transmission via presynaptic D2Rs. (A) Dopamine reversibly depressed IPSPs via D2Rs. Vm = −55 mV. (Scale bars: 4 mV, 400 ms.) (Insets) IPSPs recorded before, during, and 30 min after drug applications, respectively. (B) CV of IPSPs before, during, and 30 min after drug applications. *P < 0.05 and **P < 0.01 (paired Student’s t tests). (C) PPR analysis: dopamine application increased the PPR of IPSCs, which was blocked by subsequent application of haloperidol (C1), but not SCH23390 (C2). Vc = −65 mV. (Scale bars: 25 pA, 20 ms.) *P < 0.05; n.s., not significant (paired Student’s t test).