title: A relationship between substance P receptor and retinal fibers in the rat suprachiasmatic nucleus.
abstract: The suprachiasmatic nucleus (SCN) in the hypothalamus controls many of the circadian rhythms in mammalian species. In the present study, we investigated the location of substance P receptor (SPR)-containing neurons in the rat SCN, using a specific antibody against SPR, which corresponds to the NK-1 subtype of tachykinin receptors, and also examined the synaptic relationship between SPR-containing neurons and retinal fibers at the ultrastructural level. An SPR-immunoreactive meshwork of labeled somata and dendrites was identified in the SCN. The strongest SPR-immunoreactivity was observed in the dorsal and lateral parts of the SCN. Many labeled somata were identified there and their dendrites protruded ventrally from their somata. A few SPR-immunoreactive somata were observed also in the ventral part of the SCN and within the optic tract. In the SCN of eye-enucleated animals, degenerating retinal fibers were shown to terminate on SPR-immunoreactive dendrites forming asymmetrical axo-dendritic contacts.
authors.affiliation: Osaka Prefectural College of Nursing, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takatsuji
authors.forename: E
authors.initials: E
authors.lastname: Senba
authors.forename: P W
authors.initials: PW
authors.lastname: Mantyh
authors.forename: M
authors.initials: M
authors.lastname: Tohyama
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009412:Nerve Fibers / Q000737:chemistry*; D009474:Neurons / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D018040:Receptors, Neurokinin-1 / Q000032:analysis*; D012160:Retina / Q000737:chemistry* / Q000648:ultrastructure; D013493:Suprachiasmatic Nucleus / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D018040:Receptors, Neurokinin-1