AFFERENT CONNECTIONS OF THE PREOPTIC REGION IN THE RAT / 解剖学报

ABSTRACT

The afferent connections of the preoptic region in the rat were studied with retrograde horseradish peroxidase (HRP) method.The mico-injection syringe needle or microelectrophoretic pipette was inserted vertically into the brain. In some cases, the injection was made with the needle inclined and directed contralaterally or in inclined direction through the cerebellum.The results were as followsFollowing HRP injection into the medial preoptic area, labeled neurons were found in periventricular hypothalamic gray, paraventricular nucleus, anterior hypothalamic nucleus, supraoptic nucleus, ventromedial hypothalamic nucleus, posterior hypothalamic nucleus and locus coeruleus in all cases. In some cases, labeled cells were also observed within bed nucleus of stria terminalis, dorsal raphe nucleus. In addition, in a few cases, a small number of labeled cells could be found in lateral septal nucleus, medial septal nucleus, periaqueductal gray matter and interpeduncular nucleus.After injection into the region between the medial and lateral preoptic area, besides the above mentioned labeled nuclei, there were still a number of labeled cells found in paratenial nucleus, nucleus reuniens and lateral hypothalamic nucleus, in some cases also found in the supramammillar nucleus, and in one case even in the cortical and medial amygdalar nuclei.Following the injection of HRP into the anterior hypothalamic nucleus, retrograde labeling of neurons was observed within the lateral septal nucleus, preoptic periventricular nucleus, medial preoptic nucleus, supraoptic nucleus, periventricular hypothalamic nucleus, paraventricular nucleus, ventromedial hypothalamic nucleus, periaqueductal gray matter and locus coeruleus in all cases. Among them, supraoptic and paraventricular nuclei were labeled bilaterally in some cases.