Figure 7.
Schematic illustrating how the release of dopamine may mediate the IPSC. a, Comparison of the D2-IPSC (black) with the current evoked by dopamine (100 μm, 100 ms, red). The duration of the IPSC is longer than the current evoked by a brief application of dopamine (gray). b, Two models may account for the late phase of the IPSC: increased diffusion of low [DA] to recruit new receptors (i), diffusion of the peak [DA] over time to prolong the duration of receptor signaling (ii). c, Left shows currents in patch recordings induced by 2 applications of dopamine. The red trace is the current induced by a 100 ms application of 100 μm, and the gray trace is that induced by a 500 ms application of 100 nm. Right illustrates the IPSC (black trace) and a dark red trace that is the sum of the short (red) and long (gray) traces from the experiment shown on the left. The traces below are the open tip recordings illustrating the time of application of dopamine.