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Objective To investigate the effects of different concentration and inhalation duration time of isoflurane on cognitive performance and the expression of GABAR1 and NMDAR2B in aged SD rat cerebral temporal lopes.Methods Aged male SD rats (9 months) were randomly divided into control group (n=10) and test group (n=80).The control group received air at room tempreture.Test groups were divided into four groups: group S1 (1.5%-2 h),group S2 (2.5%-2 h),group S3 (1.5%-4 h),group S4 (2.5%-4 h)according to isoflurane concentration and inhalation duration time.Every group was equally divided into two groups and Morris water maze test was performed day 1 and day 7 after isoflurane inhalation.Then the right temporal lobe was gathered and the mRNA transcription and protein expression of GABAR1 and NMDAR2B were detected by RT-PCR and Immunofluorescence technique.Results One day after isoflurane inhalation, accompanied with increased isoflurane concentration and inhalation duration, the spatial memory ability of every test group decreased continually, and the mRNA transcription and protein expression of GABAR1 increased and the mRNA transcription and protein expression of NMDAR2B decreased compared with control group (P<0.01).Seven days after isoflurane inhalation, the spatial memory ability of group S4 decreased, the mRNA transcription and protein expression of both GABAR1 increased, the mRNA transcription and protein expression of NMDAR2B decreased compared with control group and the other test groups (P<0.01).There was no significant difference between the control group and groups S1, S2, S3.Conclusion Continuous inhalation of isoflurane has great effects on spatial memory ability.And impaired spatial memory by isoflurane inhalation of high concentration with long duration is present in a long time.Thoses are related with the mRNA transcription and protein expressions of GABAR1 and NMDAR2B in cerebral temporal lope.
RESUMO
Objective To observe the change of learning and memory quality and the expression change of GABAR1 and NMDAR2B in aged SD rat cerebral temporal lobe by propofol injection and discuss the influence that may be caused by propofol.Methods Aged male sd rats were randomly divided into three groups,each group of 20.Propofol intraperitoneal injection was implemented to groups P1 and P7 according 50 mg/kg and maintained anesthesia for 3 hours.The same dose of emulsion was given to control group. Morris water maze test was done in the first days and the seventh days after intraperitoneal injection.Then the left temporal lobe was gathered and the mRNA transcription and protein expression of GABAR1 and NMDAR2B were detected by FISH and Immunofluorescence technique.Results Compared with control group,the latent time of group P1 was significantly prolonged and the numbers of passing through the target frequency were decreased significantly (P <0.05).Group P7 had no significant differences.The mRNA transcription and protein expression of GABAR1 in group P1 were increased significantly and the mRNA transcription and protein expression of NMDAR2B in group P1 were decreased significantly (P <0.05 ). Group P7 had no significant differences.Conclusion The short-term memory of brain declined after propofol was used.This may be related to the function of temporal lobe.The mechanism may be related to the up regulation of GABAR1 and the down regulation of NMDAR2B simultaneously.