title: The fine structures of the VIP-like immunoreactive neurons in the cat hypothalamus.
abstract: The fine structures of the VIP-like immunoreactive neurons in the suprachiasmatic nucleus (SCN) and the arcuate nucleus ( ARN ) of the cat hypothalamus were investigated by electron microscopic immunocytochemistry. The VIP-like immunoreactive soma and fibers could be successfully visualized by a modified PAP method. VIP-like immunoreactive neurons in both nuclei contained immunoreactive rER, Golgi complexes and many immunoreactive granules, as well as well developed mitochondria. VIP-like immunoreactive synaptic endings with synaptic membrane specialization of Gray's type I and II were found in the SCN. Moreover VIP-like immunoreactive preterminal elements that made synaptic contact with VIP-like immunoreactive neuronal soma were also detected. On the other hand, it was difficult to detect typical preterminal endings with immunoreactivity in the ARN ; however, VIP-like immunoreactive processes in contact with the basement membrane of the capillaries were observed. These observations indicate that VIP-like immunoreactive neurons in the SCN act as intrinsic neurons and are involved in neuroendocrine function in ARN .
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism* / Q000648:ultrastructure; D002415:Cats; D003594:Cytoplasmic Granules / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D007124:Immunoenzyme Techniques; D008854:Microscopy, Electron; D013493:Suprachiasmatic Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
chemical_list: D014660:Vasoactive Intestinal Peptide