title: Electron microscopic observation of pituitary adenylate cyclase-activating polypeptide (PACAP)-containing neurons in the rat retina.
abstract: The distribution and localization of pituitary adenylate cyclase-activating polypeptide (PACAP) in the rat retina were studied by immunocytochemistry with both light and electron microscopy. PACAP-like immunoreactivity (PACAP-LI) was detected in the amacrine and horizontal cells as well as in the inner plexiform layer, the ganglion cell layer and the nerve fiber layer. PACAP-LI seemed to be concentrated predominantly in the neuronal perikarya and their processes, but not in other cells in the retina. At the ultrastructural level, PACAP-LI was visible in the plasma membranes, rough endoplasmic reticulum, and cytoplasmic matrix in the PACAP-positive neurons in the inner nuclear layer. In the inner plexiform layer, PACAP-positive amacrine cell processes made synaptic contact with immunonegative amacrine cell processes, bipolar cell processes, and ganglion cell terminals. These findings suggest that PACAP may function as a neurotransmitter and/or neuromodulator.
authors.affiliation: Department of Ophthalmology, Showa University School of Medicine, Hatanodai, Shinagawa-ku, Tokyo, Japan. tamseki@med.showa-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Seki
authors.forename: S
authors.initials: S
authors.lastname: Shioda
authors.forename: S
authors.initials: S
authors.lastname: Izumi
authors.forename: A
authors.initials: A
authors.lastname: Arimura
authors.forename: R
authors.initials: R
authors.lastname: Koide
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D018870:Endoplasmic Reticulum, Rough / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D009475:Neurons, Afferent / Q000378:metabolism / Q000648:ultrastructure; D009479:Neuropeptides / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000378:metabolism* / Q000648:ultrastructure*; D012165:Retinal Ganglion Cells / Q000378:metabolism / Q000648:ultrastructure
chemical_list: C495403:Adcyap1 protein, rat; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide