Fig. 8.

Effects of retigabine on vestibular responses. A: changes in vestibular response waveforms. Responses shown were recorded before (Bas, baseline) and 20 and 120 minutes after a retigabine dose of 20 mg/kg. After 20 min, responses were delayed (P1, N1, P2) and reduced in size (P1-N1, P2-N1). Thereafter, responses were enhanced, increasing in amplitude, decreasing in latency, and lowering of threshold (120 min). Stimulus level was 6 dB re: 1 g/ms. Calibration bars indicate 2.0 ms and 1.0 μ/V for graphic. Dashed vertical lines identify latencies of P1 and P2 before drug injection. B: effects of a single dose of retigabine (filled circles) and DMSO vehicle alone (open circles) on VsEP responses. Mean values are normalized to baseline (mean value minus mean baseline) for response latencies (P1, N1), amplitudes (P1-N1), and thresholds over a period of up to 2 h following retigabine (20 mg/kg; n = 6) and DMSO (n = 9) injections. Data are means ± SD (retigabine group: black circles ± solid red lines; DMSO group: open circles ± blue dotted lines). Data to the right of the vertical dashed line represent the effects of drug or vehicle administration on VsEP responses. Baseline means were as follows: P1, 1.306 ± 0.033 ms; N1, 1.605 ± 0.071 ms; and P1-N1, 1.045 ± 0.246 μV; threshold = −10.5 ± 0.0 dB re: 1 g/ms. Stimulus level was 6 dB re: 1 g/ms.