Fig. 8.

TRP injections produce a small increase in conductance in the photoreceptor terminal. Current pulses of −0.3 nA and 0.2 sec duration and at 2 pulses/sec were injected into the receptor and synchronized to the timing of the TRP injection (bottomtrace). After the TRP injection the voltage deflection declines from 6.7 to 5.7 mV, indicating a change in input conductance from 45 to 52 nS. The recordings were made in the axon in discontinuous current-clamp mode. The toptrace is the average of four responses.