Objective:To investigate the effects of Propofol on long term neuroethology of neonatal rats and its mechanism.Methods:Totally 72 seven-day-old neonatal rats were randomly divided into group C

group P1 and group P2 (n=24).The rats in group C and group P1 were injected intraperitoneally with 7.5 ml/kg normal saline q.d for consecutive six days and on 7th/ d

the rats in group C were injected with 7.5 ml/kg normal saline while those in group P1 were injected with 75 mg/kg Propofol.The rats in group P2 were received 75 mg/kg Propofol q.d for consecutive seven days. On 7th d

the artery blood gas and glucose were tested for three rats randomly chosen in each group at 15 min after the intraperitoneal injection .On 30th

90th and 180th

seven rats randomly chosen in each group were examed by Morris water maze and open-field test.The hippocampal CAI region was decapitated in rats

the apoptosis rates of the neurons were measured by flow cytomery and the morphologic changes of the pyramidal cells were assessed quantitatively by stereology method.Results:The learning

memorizing and exploring function on 30th were declined significantly and the neuron apoptosis rates in CAI region were increased markedly in group P2 compared with those in group C and group P1(P<0.05).The volume density (Vv) and surface area density (Sv) in hippocampal CAI region in group P1 and P2 were declined with various degrees compared with those in group C (P<0.05)

with more obvious decline in group P2.On 90th and 180th/d

there was no difference in each item among three groups.Conclusion:Multiple propofol injections may impair long term neuroethology of neonatal rats

which may associated with increased neuron apoptosis and morphologic change of pyramidal cells.