Effects of electroacupuncture at Guanyuan (CV 4) or Sanyinjiao (SP 6) on hypothalamus-pituitary-ovary axis and spatial learning and memory in female SAMP8 mice

OBJECTIVE

To investigate the effects of electroacupuncture (EA) at the Guanyuan (CV 4) or Sanyinjiao (SP 6) acupoints on the hypothalamus-pituitary-ovary (HPO) axis and spatial learning and memory in female mice.

METHODS

Nine-month-old female mice with senescence-accelerated mouse prone 8 (SAMP8) were divided into three groups: the disease model, EA-Guanyuan and EA-Sanyinjiao groups. Concurrently, 9-month old female mice with senescence-accelerated mouse resistance 1 (SAMR1) were set as the control model group. The two treatment groups were given the same pattern of EA stimulation. Gonadotropin-releasing hormone, luteinizing hormone, follicle-stimulating hormone (FSH) and Serum estradiol levels in the Hypothalamus-pituitary-ovary axis were assessed by enzyme-linked immunosorbent assay to determine the HPO axis function level. Spatial learning and memory were assessed by the Morris Water Maze (MWM) test.

RESULTS

(a) HPO axis: compared with the control model group, the disease model group displayed a decrease in E2 levels (P < 0.01), and an increase in GnRH, LH and FSH levels (P < 0.01). E2 levels were increased in EA treatment groups compared with the disease model group (P < 0.05). In contrast, GnRH and LH and FSH levels were reduced (P < 0.05). EA-Sanyinjiao group was superior than EA-Guanyuan group on increasing E2 and declining GnRH levels (P < 0.01). (b) The MWM test demonstrated that the response latency in the EA-Sanyinjiao treatment group declined from day 2 to day 5 compared with the disease model group (P < 0.05), whereas the EA-Guanyuan treatment group showed no significant difference.

CONCLUSION

EA can regulate hormone (E2, FSH, LH, GnRH) levels in the HPO axis and the spatial learning and memory ability in female SAMP8 mice. Moreover, this effect may have been more pronounced in the EA-Sanyinjiao group than the EA-Guanyuan group. The underlying mechanism of the EA-induced changes may be related to gonadal hormone shifts in the HPO axis, followed by an improvement in spatial learning and memory.