Figure 3.

Dopamine suppresses the amplitude of both AMPA- and NMDA receptor-mediated components of EPSPs. (a) AMPA-mediated EPSPs recorded in the presence of APV and bicuculline were suppressed by 50 μM dopamine. Averaged traces show EPSPs recorded before (BL) and after (DA) dopamine application, and group data are shown at right. (b) Isolated NMDA receptor-mediated EPSPs recorded in the presence of CNQX and bicuculline are also suppressed by a high concentration of dopamine. Group data show a consistent suppression of the small isolated NMDA response.