The effects of repeated propofol anesthesia on spatial memory and long-term potentiation in infant rats under hypoxic conditions

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 SpragueeDawley rats were randomly assigned into six groups(n Z 14)-four control groups:lipid emulsion solvent t 50%oxygen(CO),lipid emulsion solvent t room air(CA),lipid emulsion solvent t 18%oxygen(CH),and propofol t 50%oxygen(propofoleoxygen,PO);and two experiment groups:propofol t room air(propofol eair,PA),and propofol t 18%oxygen(propofolehypoxia,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.