Objective: 

Females cope differently with stressful situations than males. We aimed to investigate the effects of stress induced by exposure to cold on females on the synaptic plasticity in the dentate gyrus and behavioral spatial memory performance.

Methods: 

Approval from Erciyes University Ethical Committee was obtained. Rats were divided into 3 groups as the control (kept at 22oC), acute cold stress (kept 2hr/day at +4oC for one day) and chronic cold stress (kept 2hr/day at +4oC for 21 days). Spatial memory was tested by Morris water maze. Also long-term potentiation (LTP) recordings were taken and blood was obtained for corticosterone measurements.

Results: 

Both of the cold exposed groups showed significant increase in the corticosterone levels when compared to the control. The corticosterone levels of the acute stress group were also significantly higher than the chronic stress group. Both experimental groups reached to the platform later than the control rats in Morris water maze test. Input-output relationship and LTP responses obtained by perforant path stimulation were found to be more depressed in the chronic stress group than the acute stress and control groups.

Conclusions: 

In the present study, chronic stress decreased LTP together with an impairment of spatial memory task. However, poor memory performance in the acute stress group was not in parallel with LTP findings. We suggest that impaired LTP caused by chronic exposition to cold is the result of exposure of long-lasting genomic effects of moderate level increase in corticosterone level.