| ObjectiveThe mortality caused by ethanol poisoning is increasing year by year.Ethanol poisoning has become a serious global public health problem.Ethanol can cause pathophysiological changes in many organ systems including central nervous system,especially in learning and memory.Hippocampus is the basic structure of learning and memory.Phosphati dylinositol-3-kinase/protein kinase B/Mammalian target of rapamycin(PI3K/Akt/mTOR)signal pathways have been shown to exist in the hippocampal structure of the brain and are associated with learning and memory.In addition,the toxicity and metabolic effects of ethanol were affected by sex factors.However,it is not clear whether the toxic effect of ethanol on learning and memory is related to the PI3K/Akt/mTOR pathway in hippocampus and whether there are gender differences.The purpose of this study was to investigate the effects of acute and chronic alcohol poisoning on learning and memory in mice,and to investigate whether the cognitive impairment induced by ethanol was related to the mTOR signaling pathway in hippocampus and whether there were gender differences.Methods1.The mice were given intragastric administration(0.1 mL/10 g)at 8 o’clock in the morning according to 12.5%,25%,and 50%ethanol.The control group was given the corresponding volume of normal saline.Acute alcohol poisoning was given by intragastric administration for 1 week and chronic alcohol poisoning for 9 weeks.2.The traditional Morris water maze was adopted to conduct behavior detection and evaluate its ability of learning and memory,after the establishment of alcohol intoxication model.And then the animals were killed and hippocampal tissue was taken.3.The expression levels of p-mTOR,mTOR,p-Akt and Akt in hippocampus of mice were detected by Western blot.4.The expression of p-mTOR-p-Akt protein in hippocampus of mice with acute ethanol poisoning was detected by immunohistochemical staining.5.Morphological changes of hippocampal tissue in mice with acute ethanol poisoning were observed by HE(Haematoxylin and eosin)stainingResults1.Morris water maze results:The escape latency of male and female rats of each group which in the navigation experiment of acute ethanol poisoning in mice,starting from 4th days,was prolonged that compared with the control group(P<0.01;P.<0.05):In the space exploration experiment of mice with acute ethanol poisoning,compared with the control group,there was no significant change in swimming speed and total swimming distance of male and female rats in each group(P>0.05).The effective area residence distance of male rats decreased significantly(P<0.01),while that of female rats in 50%ethanol group and 25%ethanol group decreased significantly(P<0.01).The effective area residence distance of female rats in 50%ethanol group and 25%ethanol group was significantly longer than that of male rats in the same concentration group(P<0.01).In the navigational experiment of mice with chronic ethanol poisoning,from the third day,the escape latency of male and female rats in each group was prolonged compared with the control group(P<0.01;P<0.05).In the space exploration experiment of mice with chronic ethanol poisoning,the swimming speed and total swimming distance of male and female rats in each group were not significantly changed(P>0.05),and the times of crossing the platform was decreased significantly(P<0.01)and increased significantly(P<0.01)in 50%ethanol group and 25%ethanol group compared with the same concentration group(P<0.01).2.Western blotting test results:In acute alcoholism mice,the expression of p-mTOR and p-Akt protein in males’ hippocampus of 50%ethanol group decreased significantly(P<0.01),and there was no significant change in p-mTOR and p-Akt protein in male’ hippocampus of each group(P>0.05)compared with the control group.But compared with the male rats,the expression of p-mTOR and p-Akt protein in the 50%ethanol group of female rats increased significantly(P<0.01).In chronic ethanol-intoxicated mice,the expression of p-mTOR and p-Akt in males’ hippocampus of the 50%ethanol group was significantly higher than in the control group(P<0.01).The female’ hippocampus p-mTOR,p-Akt protein had no significant changes(P>0.05)in each group.However,the expression of p-mTOR and p-Akt protein in the 50%ethanol females’ group was significantly lower than in the male mice(P<0.01).3.Immunohistochemical test results:In mice with acute ethanol poisoning,the expression of p-mTOR,Akt protein in males’ hippocampal CA1 region of 50%ethanol group was significantly lower than that in the control group(P<0.01).The expression of p-mTOR and p-Akt protein in hippocampal CA1 region of female rats in the 50%ethanol group was significantly lower than that of male mice in the same concentration group(P<0.01).4.HE staining results:There was no pathological changes were found in the hippocampal CAI region in the control and low dose groups.In the 25%ethanol group,the pyramidal neurons were slightly injured in the hippocampal CA1 region.In the 50%ethanol group,the number of male neurons was significantly reduced,pyramidal neurons were extensively damaged,and the extent of cell damage was more severe than female ratsConclusionsAcute and chronic ethanol poisoning can lead to decreased learning and memory in adult mice.The mechanism may be related to the abnormal expression of PI3K/Akt/mTOR signaling pathway in the hippocampus and the normal morphology and functional destruction of hippocampal neurons.In addition,all the changes above caused by ethanol have gender differences. |
