title: Vasoactive intestinal peptide (VIP)-like immunoreactive neurons located in the rat suprachiasmatic nucleus receive a direct retinal projection.
abstract: The existence of a direct projection from retinal ganglion cells to vasoactive intestinal peptide (VIP)-like immunoreactive neuronal elements in the rat suprachiasmatic nucleus (SCN) was revealed by combining analysis of degenerating axons following enucleation and electron microscopic immunocytochemistry. Degenerating axons appeared to make synaptic contact with VIP-like immunoreactive dendrite and neuronal perikarya in the ventral part of the SCN. The possibility of neuronal input from retinal ganglion cells to axons of VIP-like immunoreactive neurons was also suspected since axo-axonic synapses were detected between degenerating axons and axons with VIP-like immunoreactivity. Thus, VIP-like immunoreactive neurons in the SCN receive several neuronal inputs, including those from the retina, and may play a significant role in circadian entrainment.
authors.affiliation: Department of Anatomy, Kyoto Prefectural University of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ibata
authors.forename: Y
authors.initials: Y
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Okamura
authors.forename: F
authors.initials: F
authors.lastname: Kawakami
authors.forename: H
authors.initials: H
authors.lastname: Terubayashi
authors.forename: T
authors.initials: T
authors.lastname: Kubo
authors.forename: N
authors.initials: N
authors.lastname: Yanaihara
mesh_terms: D000818:Animals; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D012160:Retina / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000033:anatomy & histology / Q000378:metabolism* / Q000648:ultrastructure; D013493:Suprachiasmatic Nucleus / Q000033:anatomy & histology / Q000378:metabolism* / Q000648:ultrastructure; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*; D014795:Visual Pathways / Q000033:anatomy & histology / Q000378:metabolism*
chemical_list: D014660:Vasoactive Intestinal Peptide