STUDY ON THE EFFECTS OF STRESS ON THE CALCIUM STATUS OF HIPPOCAMPUS NEURON IN RATS WITH DIFFERENT ZINC STATUS AND RELEVANT MECHANISMS

Objective: To observe the behavior changes of rats in different zinc status under stress,and explore its possible mechanisms. Methods: Rats were randomly divided into 6 groups,i.e.,zinc deficiency group(ZD) and stress zinc deficiency group(SZD),pair fed group(PF) and stress pair fed group(SPF), control group(CT) and stress control group(SCT).At the end of the first week, rats of stress groups were given irregular photoelectric stimulus,25 min/d for 15 days, then their behavior was observed in open field test;[Ca 2+ ]i. Concentration and active CaM content of hippocampal cells were detected by Fura 2/AM two wave length fluorophotometry and flowcytometry respectively. Results: ZD rats had prolonged latency and decreased number of modifications in open field test;[Ca 2+ ]i content of ZD rats was significantly higher than that of CT rats;crossing ,rearing and modifying frequencies of rats in stress groups were less than those of corresponding non stress groups, especially of SZD group, so was [Ca 2+ ]i concentration of hippocampal cells; while active CaM content showed the opposite tendency. Conclusion: The results indicate that photoelectric stress can lead to abnormal behavior in rats which are worsened by zinc deficiency;the changes of [Ca 2+ ]i CaM system of hippocampal cells may be one of the relevant mechanisms underlying stress induced abnormal performance.