Neuroanatomical And Neurophysiological Study Of The Oval Nucleus Of The Bed Nuclei Of The Stria Terminalis In The Rat

Some early studies showed that the bed nuclei of the stria ter-minalis (BST) was a heterogeneous structure, and contained many neuropeptide-like immunoreactivities. Recently Ju and Swanson parcel-lated in detail the BST according to its cyto- and chemoarchitecture in the rat, and demonstrated that it consisted of well over a dozen clearly distinct nuclei or cell groups. They also found' that the oval nucleus in the lateral subdivision of the anterior BST was a homogeneous structure, and rich in neurotensin (NT)- and cortico-tropin-releasing factor (CRF)- containing neurons and CRF-, NT-, substance P- and cholecystokinin (CCK) -like immunoreactive fibers and terminals. However, much less information has been known about the hodology and chemical neuropathways of the Ov.The aims of this study were to examine the afferent and efferent connections of the Ov, to reveal the neurochemical characteristics of its pathways, and to illustrate the functional connections between the Ov and the central nucleus of the amygdala (Ce) or the lateral hypothalamic area (LHA). Immunocytochemistry, axonal transport tracing, retrograde tracing combined with immunocytochemistry and extracellular recording were the main techniques employed in this study. The main findings of the present experiments are as follows.