Fig. 4.

Dopamine release from the RPeD1 growth cone was detected by the sniffer target soma. A, An RPeD1 soma that was plated in CM was spontaneously active and fired bursts of action potentials. B, A target cell soma was juxtaposed near an RPeD1 growth cone. Scale bar, 50 μm. C, After electrical stimulation (arrowheads) of RPeD1 (bottom trace), a compound IPSP was recorded in the target cell (top trace). Di, The stimulation (arrowhead) of RPeD1 (top trace) resulted in a compound IPSP in a target cell (bottom trace). Dii, In the presence of the D₂ antagonist sulpiride (10⁻⁵m), there was no detectable response in the target cell after RPeD1 stimulation (arrowhead).