Effects of Chronic Aluminum Intoxication on Memory Function in Rats
Objective To explore the effects of chronic aluminum intoxication on learning memory function in rats.Methods Forty-eight male Wistar rats were divided into a control group and low,medium and high dose groups to establish a chronic toxicity intoxication model.The low,medium and high dose groups were gavaged with AlCl3 solution at doses of 25,50 and 100 mg·kg-1,respectively,while the control group was gavaged with an equal volume of saline for 90 days.The effects of chronic aluminum intoxication on the learning and memory ability of rats were investigated by Morris water maze experiment;brain tissue sections of rats were processed with hematoxylin/eosin(HE)and Nysted staining to observe the morphologic changes of neuronal cells in hippocampal region;the changes of CACNA1E,CALM,and BDNF mRNA expression in hippocampal region of rats were examined by real-time quantitative PCR;and the expressions of CACNA1E,CALM,and BDNF proteins in hippocampus were examined by protein immunoblot-ting experiments.Results The results of Morris water maze showed that the escape latency of the middle and high dose groups was significantly higher than that of the control group(P＜0.05 or P＜0.01),and the difference between the three dose groups was not statistically significant(P＞0.05).The results of HE and Niehlstrom staining showed that the neuronal cells of the hippocam-pal CA1 and CA3 regions of the control group were arranged in an orderly manner,with a normal morphology and structural integrity.The morphological and structural changes of cells in each dose of aluminum intoxication group correlated with the aluminum exposure dose:with the in-crease of aluminum exposure dose,the cells were significantly loosely arranged,the morphology changed from round/elliptical to flat spindle,the cytoplasm was reduced,the staining was changed from dark to light,and the Nitidulin vesicles became significantly less.Compared with the control group,CACNA1E,CALM,BDNF mRNA and protein expression levels were significantly lower in the medium and high dose groups(P＜0.05 or P＜0.01).Conclusion Aluminum intoxication can cause cognitive impairment in rats,which may be associated with reduced expression levels of CACNA1E,CALM and BDNF in hippocampal tissue.
aluminumratlearning and memory abilitycognitive impairmentHippocampus
万方数据
维普
