| Objective To investigate the changes of the capillaries in the CA1 of hippocampus and dentate gyrus (DG) in the depression rats induced by chronically unpredicted stress (CUS).Methods Male Sprague-Dawley (SD) rats were randomly divided into the control group (n=10) and the model group (n=10).The depression model of rats was made by giving rats CUS for five weeks. The control group rats were not given CUS. The sucrose consumption test and the open-field test were used to identify if the depression rat model was successfully made. After the depression model of rats was successfully made,5 rats were randomly selected from each group. One hemisphere was randomly sampled from each rat, and the volumes of the hippocampus, the CA1 and the DG were investigated with the stereological methods. The blocks (1 mm×1 mm×1 mm) were randomly sampled from the sampled hemispheres.4μm sections were cut according to the isector principle. Capillaries were marked with the immunohistochemistrical technique. Under light microscope with the magnification of 100,10 views of visions were randomly obtained from each section. The immunohistochemistrical technique and the stereological methods were used to quantitatively investigate the capillaries in the CA1 of hippocampus and the DG.Results 1. The rat weights, the results of the sugar water preference and the results of the open-field test were significantly different between two group (P<0.05, P<0.05, P<0.05).2. The volumes of the hippocampus, the CA1 and the DG in model group were significantly lower than those in the control group (P<0.05, P<0.01, P<0.05).3. The total length, total volume, total surface area and average diameter of the capillaries in the hippocampal CA1 were significantly decreased when compared to the control group (P<0.05, P<0.01, P<0.05, P<0.05).4. The total volume, total surface area and average diameter of the capillaries in the DG were significantly decreased when compared to the control group (P<0.05, P<0.05, P<0.05), but the total length of the capillaries in the DG was not statistically significant between the two groups (P>0.05).Objective To investigate the effects of running exercise on the changes of the capillaries in the CA1 of hippocampus and DG in the depression rats induced by chronically unpredicted stress.Methods Male SD rats were randomly divided into the control group (n= 10), the model group (n= 10) and the running model group (n= 10). The depression model of the model group and the running model group rats was made by giving rats CUS. The control group rats were not given CUS. The sucrose consumption test, the open-field test and the forced swimming test were used to identify if the depression rat model was successfully made. After the depression model of rats was successfully made, the running model group had running exercise. After 4 weeks running exercise, the sucrose consumption test, the open-field test and the forced swimming test were used again.5 rats were randomly selected from each group after these tests. One hemisphere was randomly sampled from each rat, and the volumes of the hippocampus, the CA1 and the DG were investigated with the stereological methods. The blocks (1 mm×1 mm ×1 mm) were randomly sampled for sampled hemispheres.4 μm sections were cut according to the isector principle. Capillaries were marked with the immunohistochemistrical technique. Under light microscope with the magnification of 100,10 views of visions were randomly obtained from each section. The immunohistochemistrical technique and the stereological methods were used to quantitatively investigate the capillaries in the CAl of hippocampus and the DG.Results 1. After 4 weeks stress, compared with the control group, the body weight, the preference of sucrose and the open-field scores of both model group and the running model group rats were significantly lower (P<0.01, P<0.01, P<0.01, P<0.01, P<0.01, P<0.01, P<0.01), the immobility time in the forced swimming was significantly increased (P<0.05, P<0.05), but there was no difference between the model group and the running model group (P>0.05, P>0.05, P>0.05, P>0.05). After 4 weeks running exercise, compared with the control group, the body weight, preference of sucrose, open-field scores and the immobility time in the forced swimming of the running model group rats were no significantly different (P>0.05, P>0.05, P>0.05, P>0.05), the body weight, the preference of sucrose and the open-field scores of the model group were significantly lower (P<0.05, P<0.05, P<0.05), the immobility time in the forced swimming was significantly increased (P<0.05). The preference of sucrose of the running model group was significantly increase when compared with the model group (P<0.05), but there were no difference in the body weight, open-field scores and immobility time in the forced swimming between two groups.2. Compared with the control group, the volumes of the hippocampus, the CA1 and the DG in model group were significantly lower (P<0.05, P<0.01, P<0.05), and those in the running model group were not different (P>0.05, P>0.05, P>0.05). The volumes of the hippocampus, the CA1 and the DG in the running model group were increased than those in the control group (P<0.01, P<0.05, P<0.05).3. The total length, total volume and total surface area of the capillaries were significantly decreased (P<0.01, P<0.01, P<0.01), and average diameter of the capillaries was not different (P>0.05) in the hippocampal CA1 of the model group when compared to the control group. The total length, total volume and total surface area of the capillaries in the running model group were increased (P<0.05, P<0.01, P<0.01), and average diameter of the capillaries in running group was not different (P>0.05) when compared to those in the hippocampal CA1 of model group. There were no differences in the total length, total volume, total surface area and average diameter of the capillaries in the hippocampal CA1 between the running model group and the control group (P>0.05, P>0.05, P>0.05, P>0.05).4. The total length, total volume and total surface area of the capillaries were significantly decreased (P<0.01, P<0.01, P<0.01), and average diameter of the capillaries was not different (P>0.05) in the hippocampal DG of the model group when compared to the control group. The total length, total volume and total surface area of the capillaries in the running model group were significantly increased (P<0.05, P<0.01, P<0.05), and average diameter of the capillaries in the running model group was no difference (P>0.05) when compared those in the hippocampal DG of model group. There were no differences in the total length, total volume, total surface area and average diameter of the capillaries in the hippocampal DG between the running model group and the control group(P>0.05, P>0.05, P>0.05, P>0.05).General conclusions1. The volumes of the hippocampus, the CA1 and the DG were decreased in depression model rats when compared to the control group.2. There existed the hippocampal capillary changes in the CA1 and the DG in depression model rats.3. Running exercise could improve depression behaviors of depression model rats.4. The volumes of the hippocampus, the CA1 and the DG in depression model rats were significantly increased after running exercise.5. The hippocampal capillary changes in the CA1 and the DG in depression model rats were protected by running exercise. |
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