A. Representative traces show VPM spike firing in response to depolarizing current injections from RMP. B. The number of spikes at each current injection was analyzed by a two-way repeated measures ANOVA (WT: n = 12 cells from 8 mice; DS: n = 9 from 5 mice; Genotype: F(1,19) = 7.992, p = 0.011, Interaction: F(32,608) = 4.677, p < 0.001) with posthoc Sidak’s tests at each current injection (*p < 0.05). C. Rheobase for WT (n = 13 cells from 8 mice) and DS (n = 9 cells from 5 mice) neurons were analyzed by unpaired t-test (**p = 0.004). D. Spike latency for WT (n = 12 cells from 8 mice) and DS (n = 8 cells from 5 mice) neurons were compared by an unpaired t-test (*p = 0.037). E. The frequency of the first 3 spikes and last 2 spikes were plotted for each cell across current injections. Linear regression of WT and DS data yielded the plotted lines with 95% CI bands, and fits were compared by sum of squares F tests. First 3 spikes: F (2,244) = 36.50, p < 0.001. Last 2 spikes: F (2,244) = 59.13, p < 0.001. F. Spike frequency adaptation ratios (last 2 spikes/first 3 spikes) were averaged across all current injections for each cell and compared by an unpaired t-test (p =0.860). G. Representative traces show rebound burst firing upon recovery from hyperpolarization. H. Spikes per burst (p = 0.39) and (I) burst latency (p = 0.46, WT: n = 14 cells from 8 mice, DS: n = 9 cells from 5 mice) were analyzed by unpaired t-tests. The symbols in all bar graphs represent individual neurons.