ABSTRACT
AIM:To investigate the expression of synaptophysin in the CA1 region of hippocampus and prefrontal cortex (PFC) of rats with posttraumatic stress disorder (PTSD) , and to explore the mechanism of spatial memory changes in PTSD rats.METHODS:Healthy adult SD rats (n=36) were randomly divided into 2 groups:control group and model group, with 18 rats in each group.The rats in model group was continuously given single prolonged stress (SPS) to construct the PTSD model.Morris water maze (MWM) was used to test the learning and memory ability of the rats in the2 groups.The protein expression of synaptophysin in the hippocampal CA1 area and PFC was examined by immunohistochemistry, Western blot and immunofluorescence experiments.RESULTS:The latency of the rats in searching for the underwater platform in model group was significantly longer than that in control group from the 2nd day (P<0.01) in the MWM experiment, the target quadrant swimming time was significantly shortened (P<0.01) , and the times of crossing the platform were also significantly reduced (P<0.01).The results of immunohistochemistry, Western blot and immunofluorescence experiments showed that the expression of synaptophysin was obviously reduced in the CA1 region of hippocampus and PFC in model group as compared with control group (P<0.05 or P<0.01).CONCLUSION:The reduction of spatial memory ability in PTSD rats may be associated with the decreased expression of synaptophysin in the CA1 region of hippocampus and PFC.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of chronic stress on spatial cognitive ability in different sex mice.</p><p><b>METHODS</b>Thirty-two adult KM mice were divided into four groups (n=8): male control and chronic stress group, female control and chronic stress group. We used the modified Kaz's methods to build on the chronic stress model of mice, and then used the place navigational testing and the probe trial testing by the Morris water maze to measure the spatial cognitive ability of mice.</p><p><b>RESULTS</b>Following two weeks stress treatment, in the place navigational testing, to male group, the average latency to find the platform in water maze of chronic stress group was longer than that of the control; to female group, the average latency of chronic stress group was shorter than the control. Moreover, the male stress group showed faster swimming speed but longer latency to find the platform. In the probe trial testing the female chronic stress group spent more time in the target quadrant compared to the male chronic stress group.</p><p><b>CONCLUSION</b>Two weeks' chronic stress could impair male mice's spatial cognitive ability, but improve the female's.</p>