DISTRIBUTION OF SEROTONIN-IMMUNOREACTIVE FIBERS AND TERMINALS IN THE BED NUCLEI OF STRIA TERMINALIS IN THE RAT / 解剖学报

ABSTRACT

Based upon Ju and Swanson's studies on the eytoarchitecture of the bed nuclei of stria terminalis (BST) of the rat, the present work studies in detail the distribution of serotonin-immunoreactive fibers and terminals (5-HT-ir fibers) in the BST of the rat with ABC or PAP technique visualized with glucose oxidase-DAB-nickel method. The results are as followsithree types of 5-HT-ir fibers were identified in the BST, viz. thick fibers, thin fibers and varicose fibers. Only varicose fibers were found in the stria extension of the BST, whereas the rest of the BST contained other types as well. In the oval nucleus, juxitacapsular nucleus, fusiform nucleus, posterior dorsal nucleus and principle nucleus,all three types of 5-HT-ir fibers were observed, while the remaining parts of the BST were occupied with thin and varicose fibers. These fibers were distributed unevenly in the BST, with highest density in the ventromedial part of the anterior ventral area and the ventrolateral part of the posterior division; moderate density in the anterior dorsal area, the ventrolateral part of the anterior ventral area and the dorsolateral part of the posterior division; and were scattered in the anterior lateral area and the medial part of the posterior division. The difference in density of 5-HT-ir fibers among various areas of the BST corresponds generally with the sequence of ontogenesis of the BST. Mismatch of the distribution of 5-HT-ir fibers and 5-HT receptors in the BST of the rat is also discussed.