Objective: To compare the effects of acupuncture stimulation of different acupoints on discharges of hypothalamic sexual arousal stimulation-related excitatory neurons in the rat so as to selected effective acupoints for regulating genito-endocrine function.Methods: Experiments were performed in 32 female Sprague-Dawley rats.Examination of vaginal castoff cell smear(HE staining) was performed to determine the rats' estrous cycle.Those being in proestrus/estrus were 14 animals and those being in diestrus/metaestrus were 18.Extracellular discharges of neurons within the medial preoptic area

the arcuate nucleus and the paraventricular nucleus of the hypothalamus(AP: 4.0-9.0 mm

R: <1.0 mm

L: <2.0 mm) were recorded by using glass micro-pipettes in anesthetized rats(10% urethane).Sexual arousal stimulation was made by using a cotton-ball-stick to touch the clitoris repeatedly(30 s).When a marked change of the neuronal firing rate was found

β-estradiol(20 ng/mL

1.5-2.5 mL/kg) was injected intravenously from the external jugular vein for observing its feedback regulatory effect.Acupoints "Neiguan"(PC 6)

"Shanzhong"(CV 17)

"Jueyinshu"(BL 14)

"Zhongwan"(CV 12)

"Shenshu"(BL 23)

"Guanyuan"(CV 4)

"Zigong"(EX-CA 1) and "Zusanli"(ST 36) were punctured and stimulated manually by twirling the acupuncture needle continuously for 30 s.Results: After manual acupuncture

the sequence of acupoints with a stronger excitatory reaction of the firingrates of the hypothalamic neurons related to sexual arousal stimulation was EX-CA1

CV4

ST36

BL23

CV12

BL14

PC6 and CV17 in proestrus/estrus;and CV4

EX-CA1

ST36

CV12

BL23

BL14

PC6 and CV17 respectively in diestrus/metaestrus.According to the place of the stimulated acupoints potentiating the electrical activity of the hypothalamic sexual arousal stimulation-related neurons

the sequence from stronger to the weaker responses was lower abdomen(below umbilicus)

lower limb

lower back(L1-S5)

upper abdomen

upper back(above T12)

thorax

and upper limbs.After administration of estradiol

the excitatory response of these sexual arousal-related neurons decreased significantly in both estrus and non-estrus(P<0.05).Conclusion: Acupuncture can effectively activate the electrical activity of hypothalamic sexual arousal stimulation-related excitatory neurons.The closer the acupoint to the genital organs

the stronger is the excitatory effect

including "Zigong"(EX-CA 1)

"Guanyuan"(CV 4) and "Zusanli"(ST 36) among the 8 acupoints observed.