Objective To investigate the effects of repeated restraint stress(RRS)and single prolonged stress(SPS)on fear memory and its generalization in mice.Methods Eight-week-old male C57BL/6J mice were randomly divided into four groups.The experimental groups were treated with either RRS or SPS,while the corresponding control groups underwent no treatment.Anxiety levels were assessed using the elevated plus maze test,and fear memory and its generalization were evaluated using the fear conditioning test.Results Seven days after stress treatment,both RRS and SPS mice exhibited significant anxiety-like behaviors compared to control mice(t=5.043,5.364;P＜0.01).Twenty-four hours after shock,the freezing time in the shock context did not differ significantly between RRS mice and control mice(P＞0.05).However,on days 7 and 14 after shock,the freezing time in the shock context was still significantly higher in RRS mice compared to a new context(P＜0.001).For SPS mice,their freezing levels in the shock context 24 hours post-shock were significantly higher than those in control mice(P＜0.01).Both groups showed higher freezing time in the shock context compared to a new context;however,7 days post-shock,the freezing time in the shock context for SPS mice did not differ significantly from that in the new context,whereas control mice showed significantly higher freezing time in the shock context compared to the new context.Conclusion SPS enhances contextual fear memory and promotes its generalization in mice,while RRS has no significant impact on contextual fear memory or its generalization.
维普
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