Fig. 1.

Sleep-wake states in the rat shown by EEG and EMG activity across the three major states, Waking (W), Slow Wave Sleep (SWS), and Paradoxical Sleep (PS) and their sub states (active, a, and quiet, q, W) or transitional (t) stages. Colors represent different activities of the EEG and EMG in the different states and the symbols the different neurons which discharge maximally during those states or activities, as represented in Figs. 2 and 3. PF, prefrontal cortex; RS, retrosplenial cortex