Abstract:

Objective To investigate the expression of brain-derived neurotrophic factor (BDNF) in different areas of brain in rats with chronic unpredictable mild stress (CUMS), and explore the effects of antidepressant on expression of BDNF. Methods Twenty-four male SD rats were randomly assighed to control group (group A), CUMS group (group B) and CUMS + citalpram group (intraperitoneal injection of citalpram 2 mL once a day, 10 mg/kg) (group C), with 8 rats in each group. The experiment lasted for 6 weeks. Body weight was measured each week, sugar preference was evaluated every 3 weeks, and behavior of rats was assessed through open field tests before model establishment and 6 weeks after model establishment. Animals were sacrificed after 6 weeks, brain tissues were obtained, and Real-Time PCR was employed to detect the expression of BDNF mRNA in different areas of brain. Results At the end of the sixth week, rats in group B had significantly lower sugar preference than group A and group C (P＜0.05), and had more behavior. After the beginning of stress experiment, the body weight of rats in group B and group C was significantly lower than that in group A (P＜0.05). The expression of BDNF mRNA in hippocampus of rats in group B was higher than that in group A, while there was no significant difference between them (P=0.07). The expression of BDNF mRNA in striatum of rats in group C was significantly lower than that in group A (P＜0.05). Conclusion Chronic stress may increase the expression of BDNF in hippocampus, while antidepressant may decrease the expression of BDNF in striatum.

Key words: chronic unpredictable mild stress, depression, brain-derived neurotrophic factor