Immunohistochemical localization of oxytocin in hypothalamus of lamb

The immunohistochemical SP method was used to study the distribution of oxytocin in the hypothalamus of the lamb. The oxytocin-immunohistochemical (OT-IR) neurons mainly distributed over nucleus pareventricularis and nucleus supra-optious. In addition, OT-IR neurons were also found in nucleus circularis, nucleus supra-opticus diffuses, nucleus arcuatus, nucleus periventricularis, nucleus perifornicalis, area anterior hypothalami, area lateralis hypothalami, nucleus posterior hypothalami and nucleus mamilaris. OT-IR nerve fibers were only observed in nucleus paraventricularis, nucleus supra-opticus (diffuses), nucleus supra-optious, nucleus suprachiasmaricus and so on. Also, some nerve fibers were found in the medium eminence and the surrounding area of the third ventricle. These results suggested that the distribution of OT in the hypothalamus of dairy goat is extensive and the physiological effection is on target cells by blood circle after releasing by three channels which are the third ventriculus(cerebrospinal fluid),neurohypophysis and blood vessel.