Propofol is widely used as an intravenous drug for induction and maintenance in general anesthesia. Hypoxemia is a common complication during perianesthesia. We want to know the effect of propofol on spatial memory and LTP (Long-term potentiation) under hypoxic conditions. In this study

84 seven-day-old Sprague–Dawley rats were randomly assigned into six groups (n = 14)-four control groups: lipid emulsion solvent + 50% oxygen (CO)

lipid emulsion solvent + room air (CA)

lipid emulsion solvent + 18% oxygen (CH)

and propofol + 50% oxygen (propofol–oxygen

PO); and two experiment groups: propofol + room air (propofol–air

PA)

and propofol + 18% oxygen (propofol–hypoxia

PH). After receiving propofol (50 mg/kg) or the same volume of intralipid intraperitoneal (5.0 ml/kg)

injected once per day for seven consecutive days

the rats were exposed to 18% oxygen

50% oxygen and air

until recovery of the righting reflex. We found that the apoptotic index and activated caspase-3 increased in the PH group (P < 0.05) compared with the PA group

fEPSP (field excitatory postsynaptic) potential and success induction rate of LTP reduced in all propofol groups (P < 0.05). Compared with the PO group

the fEPSP and success induction rate of LTP reduced significantly in the PA and PH groups (P < 0.05). Moreover

compared with CH group

the average time of escape latency was longer

and the number of platform location crossings was significantly reduced in the PH group (P < 0.05). Thus

we believe that adequate oxygen is very important during propofol anesthesia.