Fig. 4

DHPG-induced increase of intrinsic excitability requires dendritic persistent Na⁺ currents. a Representative traces demonstrate the effects of DHPG and subsequent addition of riluzole of AP firing frequency and afterpotentials at current injections of 40 and 160 pA. b FI curve summarizes the effects of DHPG and subsequent addition of riluzole on AP firing frequency in response to square pulse injections. (n = 8, control vs. DHPG, *P < 0.05, **P < 0.01, ***P < 0.001). c Bar graphs summarize the effects of DHPG and subsequent addition of riluzole on afterpotentials following 160 pA square pulse injections. (n = 8, control vs. DHPG, *P < 0.05, n.s., P > 0.05). d and e Left, a schematic drawing of experimental condition demonstrates a neuron being recorded with somatic local applications of riluzole. d Right, FI curve summarizes the effects of DHPG and subsequent dendritic local addition of riluzole on AP firing frequency in response to square pulse injections (n = 8, DHPG vs riluzole, **P < 0.01). e Right, FI curve summarizes the effects of DHPG and subsequent somatic local addition of riluzole on AP firing frequency in response to square pulse injections (n = 8, DHPG vs. riluzole, n.s., P > 0.05)