Different types of responses in PNC neurons evoked by depolarizing current injections. A-C, Whole-cell recordings from three individual PNC cells that showed burst firing in response to depolarizing currents. While the firing rate of cells in A and B monotonically increased with increasing currents, the cell in C only showed spikes in response to intermediate currents. D, Regular non-adapting spiking with monotonically increasing firing rates to increasing currents was observed in another population of cells. E, Responses from a PNC cell that showed irregular fast-adapting spiking. Although increasing currents in this cell decreased interspike intervals the total number of spikes elicited remained constant. Resting potentials of the cells were -61.6 mV, A, -62.5 mV, B, -61.2 mV, C, -58.4 mV, D, and -50.9 mV, E. Current amplitudes applied to each cell were 5, 10, 15, and 20 pA.