Figure 7.

Nitric oxide suppresses gap-detection on a cellular level. (A) Mouse SPN neurons show offset firing in responses to gaps of different durations (60–20 ms) embedded in trains of electrically evoked IPSPs. (B) Bath application of an NO donor reduced the number of action potentials per gap and delayed the action potential within the gap so that only longer gaps were detected. Stimulus artifacts were removed for clarity. (C) The number of evoked action potentials increased with gap duration in controls (black bars), but was never more than one with NO (white bars). (D) Repetitive stimulation (10 IPSP trains) was used to estimate gap-detection success, which is plotted here as % offset action potentials against gap duration. Threshold was defined as 50% success (dashed line); controls (black) reliably detected gaps of 20 ms or longer, but following NO, gap-detection thresholds increased to 60 ms or longer. Data plotted as mean ± s.e.m. (n indicated on the respective graph).