Propofol (PPF) was administered to behaving female rats bearing stimulating electrodes in the dorsal perforant path (DPP) and anterior piriforin cortex (PC) and recording electrodes in the dentate gyrus (DG). Population slow waves (SWs) were evoked by paired-pulse stimulation of PC at a 32-msec interstimulus interval to produce paired-pulse facilitation in awake Ss. After administration of PPF, mean amplitude of SW2 decreased immediately and remained low for 30-60 min during PPF-induced sleep and then increased to about 1.5- to 2-fold above pretreatment levels at 2-4 hrs before gradually returning to pretreatment levels. The DPP was stimulated to produce paired-pulse inhibition or facilitation of DG population spikes (PSs) in awake Ss. PS2 was more inhibited during PPF-induced sleep than during pretreatment, consistent with an increase in recurrent inhibition. An overshoot in PS2 amplitude was observed occasionally during recovery.