Objective To explore the effects of hyperbaric oxygen treatment on chronic stress and glucocorticoid receptor (GR) expression in the hippocampus.Methods A total of 60 male Wistar rats were randomly divided into a restraint group,an HBO (hyperbaric oxygen) group,an HBO-restraint group and a control group using a random number table,each group with 15 animals.All the rats in the restraint and HBO groups were constrained by immobilizing their fore-and hind-limbs on a self-made frame for 3h daily for 21 days,and those in the HBO group received HBO treatment once daily for the same 21 days.The HBO-restraint group was immobilized in the morning and treated with HBO in the afternoon.The control group was reared without any special intervention.On the 1st,11th and 21st day of treatment,rats from the different groups were assessed using the open field test.On the 21st day,all the animals were sacrificed and their brains were harvested to detect GR expression.Results In the open field test on the 11 th day,the restraint group scored (131.0 ± 20.6) in terms of motor level and (26.5 ± 4.6) for exploratory behavior,both significantly higher than before restraint and significantly higher than those in the HBO-restraint group at the same time point.Immunofluorescence assay showed that GR expression in the hippocampus of the restraint group was significantly decreased compared with the control group.There was no significant difference,however,between the HBO-restraint group and the control group.Conclusion Chronic restraint stress induces changes in behavior and GR expression in rats which can be alleviated by hypbaric oxygen treatment.

Objective To investigate regional spontaneous brain activity in mild cognition impairment (MCI) patients with amnesic (aMCI) and non-amnesic (naMCI).Methods Twenty-five aMCI patients,21 naMCI patients and 15 normal controls (NC) underwent resting-state functional magnetic resonance imaging.The regional homogeneity (ReHo) map of the whole brain was obtained by calculating the similarity of each voxel with its nearest 26 voxel time series.The differences of ReHo map across the whole brain among three groups were compared.Results In aMCI group,ReHo values were lower in right frontal lobe and higher in left middle temporal gyrus and left cerebellum compared with NC (P＜0.05,Alphasim correction).In naMCI group,ReHo values were higher in anterior cingulate cortex and right middle frontal gyrus and lower in right parahippocampa gyrus,right middle temporal gyrus as well as right precuneus compared with NC (P＜0.05,Alphasim correction).Compared with naMCI,the ReHo values were significantly higher in left prefrontal gyrus,left middle temporal gyrus and lower in right cerebellum (P＜0.05,Alphasim correction).Conclusion There are differences in spontaneous brain activity of left prefrontal gyrus,left middle temporal gyrus and right cerebellum between aMCI and naMCI,which may be used to differentiate brain function between aMCI and naMCI patients.