FIGURE 3. Postsynaptic Ca²⁺ currents contribute to increased spiking in Type A neurons.

(A) Example of paired Type A/B responses illustrating greater spiking in Type A neurons. (B) Population overlay of responses of either Type A (red) or B (blue) neurons to Type A or B current waveforms. Type A neuron responses in Ni²⁺ are in teal. Steady current was injected to maintain all resting membrane potentials around −65 mV. (C) Spike probability for each simulated light pulse during injection of Type A or B current waveforms into postsynaptic Type A or B neurons. Type A neurons spiked more, regardless of the type of input waveform (A vs. B). Ni²⁺ dramatically reduces spiking in Type A neurons. (D) Number of spikes per train of ten simulated inputs. **=p<0.01, ***=p<0.001, n=5 for each condition. See also Fig. S3.