[Influence of electroacupuncture plus intragastric administration of extract of hypericum perforatum L on ethology and brain microcirculation in depression rats].

Objective: To observe the effect of combined administration of intragastric perfusion of extract of Hypericum Perforatum L (HP-L) and electroacupuncture (EA) of "Baihui" (GV 20) and "Yamen" (GV 15) on behavior and brain microcirculation in depression rats.

Methods: Female SD rats were randomized into control, model, lower-dose of HP-L (lower-dose in short, 10 mg/kg), lower-dose+ EA, higher-dose (20 mg/kg) and higher-dose+ EA groups (n = 10/group). Depression model was established by lonely raising and chronic unpredictable mild stress (tail cramping, water-deprivation, fasting, electrical shock stimulation, etc. ) for 21 days. EA (2 Hz, 1 mA) was applied to "Baihui"(GV 20) and "Yamen"(GV 15) for 20 min, once daily for 14 days. Changes of ethology including glucose-consumption during 1 h, crossing and rearing scores of open-field test during 3 min (for assessing the rats' locomoto)and laser Doppler flowmetry values of cortical regional cerebral bloodflow (r CBF) were detected, and Morris water maze test (for assessing the rats' learning-memory ability) was conducted.

Results: In comparison with the control group, the sucrose consumption, crossing and rearing scores of open-field test, the average swimming velocity (ASV). the ratios of path length and swimming duration near the hidden-platform and the path length and swimming duration far from the platform of Morris water maze test during 70 seconds, and the cortical r CBF value in the model group were decreased significantly (P < 0.01), while the total swimming distance and escape latency in the model group increased apparently (P < 0.01). Compared to the model group, the average sucrose consumption, crossing and rearing scores of open-field test, the ASV, and the ratios of path length and swimming duration near the platform and those far from the platform in the lower-dose. lower-dose + EA, higher-dose and higher-dose + EA groups, and the cortical r CBF in the lower-dose + EA and higher-dose + EA groups were increased considerably (P < 0.05, P < 0.01). The total swimming distances and escape latencies of lower-dose, lower-dose + EA, higher-dose and higher-dose + EA groups were significantly shortened in comparison with the model group (P < 0.05, P < 0.01). The sucrose consumption and crossing score were significantly higher in the higher-dose + EA group than the lower-dose group (P < 0.05). The escape latency was significantly shorter in the higher-dose + EA group than in the lower-dose group (P < 0.05). No significant differences were found among the lower-dose, lower-dose + EA and higher-dose groups the sucrose consumption, crossing score and escape latency: among the lower-dose, lower-dose + EA, higher-dose and higher-dose + EA groups in the rearing score and ASV; among the lower-dose, higher-dose and model groups in the cortical r CBF (P > 0.05).

Conclusion: EA can enhance the effect of extract of HP-L in increasing sucrose consumption, crossing score and cerebral blood flow, and in shortening escape latency in depression rats, which may contribute to their effect in improving depression. But HP-L itself has no effect on cortical microcirculation.