Does para-chlorophenylalanine produce disturbed waking, disturbed sleep or activation by ponto-geniculo-occipital...

Sleep-waking stages and PGO activity were continuously recorded for 2 days following a control injection and for 5 days following a single injection of 200 mg/kg PCPA. Following PCPA, quiet waking with desynchronized EEG activity (W-1 quiet) was increased, while waking with synchronous EEG activity (W-2) was reduced dramatically. Active waking (W-1 active) was not changed. Sleep was reduced following PCPA, in particular slow wave sleep with slow synchronous waves (SWS-2). The distribution of PGO activity on the sleep-waking stages was altered after PCPA. The sleep-waking changes preceded the PGO wave redistribution by 12--18 hours. The data do not support the PGO wave activation hypothesis for the sleep loss following PCPA administration. It is concluded that PCPA affects a deactivating, possibly slow wave producing mechanism, affecting relaxed waking and deep slow wave sleep but not sleep per se.