Figure 7.
Processes mediating the effects of Ginh. A, Input current and Vm response in the absence (black) and presence (gray) of Ginh, at 0° (left) and 180° (right) phase delays. The horizontal line is Erev for Ginh (-66 mV). B, Input current and Vm response for one stimulus cycle. Left, Subthreshold response from Figure 7A (right) in the absence (black) and presence (gray) of Ginh; average PSC amplitude reduction for the subthreshold responses during four trains: 46.6%. Center, Same traces as left, scaled to height, showing shortened membrane time constant attributable to Ginh. Right, The depolarizing force on Vm below Erev of Ginh. The current begins to increase after Vm falls below Erev (arrow). Inset, Firing rate versus phase delay for a different neuron. In the presence of Ginh (gray circles), firing rate was boosted at the low phase delays and reduced at the high phase delays compared with no Ginh (filled circles).