Study Of Suprachiasmatic Nucleus In The Needle-guided Rhythm Phase Mechanism

ObjectiveTo research the zeitgeber property of electro-acupuncture on circadian rhythm; To study the effect of SCN on phase-shift induced by electro-acupuncture through observing the change of NPY, 5—HT, NOS, Fos and VIP expression in the SCN induced by different zeitgeber.Materials and MethodsA total of 60 Syrian golden hamsters were divided into electro-acupuncture (A) group, 8-OH-DPAT (B) group, photic stimuli (C) group and seizing control (D) group(n=15). Golden hamsters moved freely following domestication. On the third day of constant darkness, hamsters were treated by electro-acupuncture, injecting 8-OH-DPAT,photic stimuli and seizing at CT9, CT15, and CT21, respectively, and 5 hamsters for each time point. At 2 hours following the treatment, the absorbance(A) values of neuropetide Y, 5—HT, nitricoxide synthase , Fos and vasoactive intestinal polypetide in hamster suprachiasmatic nucleus were observed by using immunohistochemistry and image analysis method. SPSS were used to analyze intergroup differences.ResultsThe expression of neuropetide Y, 5—HT, nitricoxide synthase , Fos and vasoactive intestinal polypetide in hamster suprachiasmaticnucleus increased obviously in electro-acupuncture group as compared with seizing control group at CT9, the expression of 5 — HT and c-fos in hamster suprachiasmatic nucleus increased obviously in electro-acupuncture group as compared with seizing control group at CT21; the expression of neuropetide Y> 5—HT> nitricoxide synthase > Fos and vasoactive intestinal polypetide in hamster suprachiasmatic nucleus increased obviously in photic stimuli group as compared with seizing control group at CT9 and CT21; the expression of5—HT\ Fos and vasoactive intestinal polypetide in hamster suprachiasmatic nucleus increased obviously in 8-OH-DPAT group as compared with seizing control group at CT9 , the expression of 5—HT and Fos in hamster suprachiasmatic nucleus increased obviously in 8-OH-DPAT group as compared with seizing control group at CT21.Conclusions1. Electro-acupuncture is one kind of nonphotic zeitgeber.2. NPY., 5-ffl\ NO, FOS and VIP of SCN involved in phase advanced induced by electro-acupuncture; 5—HT and FOS play the important roles in phase delay induced by electro-acupuncture.