Fig. 2

HFS-induced decrease of spike onset timing and jitter. a Left, representative traces in response to slow current ramp (250 pA/350 ms) injections before (black), after (red), and after in riluzole (bottom, blue). Right, representative traces demonstrate HFS-decreased spike timing onset and jitter are reversed by riluzole. b Pooled data summarizes the effects of HFS and subsequent addition of riluzole on spike onset timing and jitter (Δ onset time, n = 3, HFS vs HFS (Riluzole), *P < 0.05). c Left, averaged voltage traces from the traces shown in (a) before (black) and after (red) HFS are superimposed. Right, phase-plane plots of dV/dt vs corresponding voltage from the traces shown in (left, c) before (black) and after (red) HFS are shown superimposed. Note that the threshold for AP initiation is shifted after HFS in control (red arrow in c, n = 3; d). e Left, representative traces in response to sine wave current with theta frequency (5 Hz) via somatic pipette before (black) and after HFS (red). f Pooled data summarizes the effects of HFS in response to sine wave currents injection on spike onset timing and jitter (jitter, n = 3, control vs HFS, *P < 0.05)