RESUMEN
<p><b>OBJECTIVE</b>To study the effects of kaixinsan on behavior and expression of p-CREB in hippocampus of the chronic stress rats.</p><p><b>METHOD</b>The male Wistar rats which gained the similar scores by Open-field test were selected, then the depression model rat was produced by separation and chronic unpredictable mild stress. Open-field test was performed to detect the behavior of rats and immunohistochemistry was used to observe the changes of p-CREB expression in hippocampus.</p><p><b>RESULT</b>On the 22nd day, the body weight and sacchar-intake of the depression model rats were all lower than those of the normal rats and the body weight and sacchar-intake of the rats treated by drugs were higher compared with model rats (P < 0.01). The depressive behavior in kaixinsan 4 g x kg(-1) group was significantly improved compared with the model group, the crossing scores and rearing scores were all increased (P < 0.01) and the expression of p-CREB in CA1, CA3 and DG in hippocampus was higher than that in the model group (P < 0.05 and P < 0.01).</p><p><b>CONCLUSION</b>Kaixinsan might improve depressive behavior by increasing expression of p-CREB in CA1, CA3 and DG in hippocampus of the chronic stress rats.</p>