Figure 6.

Representative example of the response of an NREM/REM sleep-related PF/LH neuron to MnPN electrical stimulation. A, The discharge of the cell across the sleep–waking cycle. a, Expanded tracings from A marked by horizontal bar. Note that NREM/REM sleep-related neurons ceased to discharge or dramatically reduced their firing rates a few seconds before arousal. B, Response of this cell to MnPN electrical stimulation. Raster plot, PSTH, superposition of raw traces of five consecutive stimulation trials (1), and neuronal responses to 80 (2) and 100 pulses/s (3) repetitive stimuli are displayed. Note short latency (2 ms), low jitter of response (1), and ability of the cell to follow repetitive stimuli at 80 pulses/s (2). At 100 pulses/s, the neuron responds only to every other stimuli (3). These findings suggest monosynaptic activation.