Chronic Forced Swimming's Impact On Ethology And The Expression Of PSD-95 Of The Brain In Rats

Objective 1,To establish rat model of chronic forced swimming successfully;2,To observe chronic forced swimming's impact on biological, behavioral, psychological of rats;3,To observe chronic forced swimming's impact on the expression of PSD-95 in hippocampus, prefrontal cortex and basal ganglia of rats;4,To observe the effect and analysis the mechanism of MK801.Methods The rat model of chronic forced swimming is established. Randomly, rats were grouped into control group(C),simple stress group (M), intervention group(T).Weights of rats were measured on the 1st,6th,10th,14th day after chronic forced swimming; Sugar consumption experiment was done on the forth week;1% sugar and drinking water consumption was observed in rats. Liquid consumption of rats of different weights were assessed by the relative consumption. Immobiled time of each rat was calculated as behavioral indicators. Western Blot method was used to detect the expression and changes of PSD-95 in hippocampus, prefrontal cortex and basal ganglia of rats of each group.Results 1,After forced swimming,compared with the control group,the growth of wage was slower on the 14th day,the immobiled time was not significantly different among the 2nd and 4th day,the immobiled time was longer among the 5th and 14th day,the expression of psd-95 was higher in the hippocampus, prefrontal cortex and basal ganglia.After forced swimming,compared with the 1st day,the immobiled time was longer among the 2nd and 14th day.2,After injected MK801,compared with the simple stess group,the growth of wage was more obvious on the 14th day,the water comsuption was more imcreased,the immobiled time was not significantly different among the 1st and 4th day,the immobiled time was reduced among the 5th and 14th day,the immobiled time was longer on other days,the expression of psd-95 was lower in the hippocampus, prefrontal cortex and basal ganglia.Conclusion Chronic forced swimming can be established as a animal model of chronic stress and depression successfully. Chronic forced swimming can make weight gain slow, pleasure lack. Independent Activities decrease and make helplessness of rats.The expression of PSD-95 change in hippocampus, prefrontal cortex and basal ganglia after Chronic forced swimming. We speculated that PSD-95 is related to the changes of biological, behavioral, psychological after Chronic forced swimming. MK801 is able to reverse it , the mechanism may be followed: MK801 can antagonist to glutamate,and avoid over-exciting of neurons.