Abstract： Objective To explore the effect of simulated ship motion on the anesthetic sensitivity of propofol in rats,so as to provide evidence for rational application of propofol during deployment at sea.Methods The motion sickness model was developed by using the rotating-chair test.The study consisted of 2parts.( 1 ) One hundred and fifty SD rats were randomly divided into the control and the rotation groups,which were further divided into 5 sub-groups,each consisting of 15 animals,in accordance with the dosage of propofol used.The activity and behavior,rate of sleep,sleep latency and sleep duration of rats were closely observed.(2) Thirty-two SD rats were randomly divided into the control group (group 1 ),the rotation group (group 2),the anesthesia group (group 3 ) and the rotation plus anesthesia group ( group 4),each consisting of 8 animals.The acetylcholine (Ach),norepinephrine (NE),γ-aminobutyric acid (GABA),glutamic acid (Glu) in the brain cortex,thalamus and hippocampus were determined respectively in the four animal groups.Results Within the dosage levels of 150 mg/kg-250 mg/kg,the sedative effect of propofol increased progressively with the increase of dosage ( P ＜ 0.01 ).When propofol levels reached 150 mg/kg,200 mg/kg and 250 mg/kg,the sleep time for the rotation group was (21.33 ± 8.08),(67.67 ±21.07) and (97.38 ±23.79)/min,and the sleep time for the control group was ( 13.15 ± 7.64),(42.60 ± 20.79) and (73.40 ± 21.28)/ min respectively (P ＜ 0.01 ).And there was statistical significance,when comparisons were made between the groups (P ＜0.01 ).The following predominant tendency could be seen in the change of neurotransmitters:in the brain cortex and thalamus,the neurotransmitter level was elevated for the animals in group 2,the neurotransmitter level was decreased for the animals of group 3 and it was further decreased for the animals of group 4; In hippocampus,the neurotransmitter levels in all other groups were also decreased,when comparisons were made with that of group 1,with an average value of group 1 ＞ group 2 ＞ group 3 ＞ group 4.Conclusions In clinical application of general dosage of 150 mg/kg-250 mg/kg,simulated ship motion could obviously increase the anesthetic sensitivity of propofol in rats,however the mechanism involved should be further studied.