Supplementary Figure 6: AP threshold and latency after GABAergic and glutamatergic synaptic stimulation.
From: Bidirectional GABAergic control of action potential firing in newborn hippocampal granule cells
(a) Phase plot of an AP generated by synaptic stimulation in a young DCX+ granule cell. Inset, AP trace used for phase plot. Black, original data. Gray, after smoothing with a Savitzky-Golay filter (2nd order, 1 ms window width). (b) AP threshold and EGABA are similar in young granule cells (n = 13 and 10, p = 0.6330, Mann-Whitney U test) but highly different in mature neurons (n = 52 and 6, p < 0.0001, Mann-Whitney U test). (c) Numbers of spikes elicited by GABAergic and glutamatergic inputs at different latencies after ML-stimulation onset. Data were fitted with a Gaussian distribution. Inset, Representative trace of AP firing induced by combined GCL- and ML-stimulation from a holding potential of –80 mV. Stimulation protocol same as in Figure 6c(ii) with low GCL burst stimulation (blue) followed by ML stimulation (red). (d) Same as c for inputs mediated only by GABAergic synapses. (e) Overlay of Gaussian distributions of GABA + glutamate (red) and GABA-only (green) APs normalized to the integral. (f) Cumulative distribution of AP latencies. Scale bars represent 10 mV, 2.5 ms for a and 20 pA, 40 ms for c,d.
