Figure 4.

Faster propagation of focal ictal discharges in slices from Scn1a^−/+ mice. (A) Schematic of the experimental configuration for the generation of focal ictal discharges. (B) Representative voltage-clamp recordings at −50 mV of an NMDA-induced ictal event in a pyramidal neuron 1 mm away from the NMDA application site in a WT (top) and a Scn1a^−/+ (bottom) mouse. (C) Left: average delays of ictal onset in pyramidal neurons from WT (N = 24 ictal events from 11 mice) and Scn1a^−/+ (N = 38 ictal events from 12 mice) animals in the presence of 4-AP. Right: average delays of ictal onset in pyramidal neurons from WT (N = 8 ictal events from 2 mice) and Scn1a^−/+ (N = 9 ictal events from 2 mice) animals in low Mg²⁺ (0 Mg²⁺). (D) Average values of ictal onset delay normalized to control in 4-AP (N = 38 ictal events from 12 mice) and low Mg²⁺ (N = 9 ictal events from 2 mice).