(a) Schematic diagram of the experimental design including the behavioral tests, treatments, and tissue collection for evaluation of the role of hippocampal estradiol receptor-α on perimenopausal affective disorders and their treatment by electroacupuncture and estradiol in rats. INT, intact; CUS, chronic unpredictable stress; OVX, ovariectomy; OVX + CUS, ovariectomy and chronic unpredictable stress. (b) Schematic drawing showing the location of the acupuncture points used in the present study. Bai Hui (GV20) is located at the right midpoint of the parietal bone. San Yin Jiao (SP6) is located on the medial lower leg, above the prominence of the medial malleolus. Guan Yuan (CV4) is located on the midpoint from umbilicus to symphysis pubis. Zi Gong (EX-CA1) is located lateral to the ventral midline and superior to the upper border of the pubic symphysis.