title: Light- and electron-microscopic analysis of neuropeptide Y-immunoreactive amacrine cells in the guinea pig retina.
abstract: We investigated the morphology and synaptic connections of neuropeptide Y (NPY)-containing neurons in the guinea pig retina by immunocytochemistry, using antisera against NPY. Specific NPY immunoreactivity was localized to a population of wide-field and regularly spaced amacrine cells with processes ramifying mainly in stratum 1 of the inner plexiform layer (IPL). Double-label immunohistochemistry demonstrated that all NPY-immunoreactive cells possessed glutamic acid decarboxylase 65 immunoreactivity. The synaptic connectivity of NPY-immunoreactive amacrine cells was identified in the IPL by electron microscopy. The NPY-labeled amacrine cell processes received synaptic input from other amacrine cell processes and bipolar cell axon terminals in stratum 1 of the IPL. The most frequent postsynaptic targets of NPY-immunoreactive amacrine cells were other amacrine cell processes. Synaptic outputs to bipolar cells were also observed in a small number of cases. This finding suggests that NPY-containing amacrine cells may influence inner retinal circuitry in stratum 1 of the IPL, thus mediating visual processing.
authors.affiliation: Department of Biology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
authors.forename: W S
authors.initials: WS
authors.lastname: Kang
authors.forename: M Y
authors.initials: MY
authors.lastname: Lim
authors.forename: E J
authors.initials: EJ
authors.lastname: Lee
authors.forename: I B
authors.initials: IB
authors.lastname: Kim
authors.forename: S J
authors.initials: SJ
authors.lastname: Oh
authors.forename: N C
authors.initials: NC
authors.lastname: Brecha
authors.forename: C B
authors.initials: CB
authors.lastname: Park
authors.forename: M H
authors.initials: MH
authors.lastname: Chun
mesh_terms: D025042:Amacrine Cells / Q000737:chemistry* / Q000648:ultrastructure; D000818:Animals; D000911:Antibodies, Monoclonal; D005260:Female; D006168:Guinea Pigs; D007124:Immunoenzyme Techniques; D008297:Male; D016253:Microscopy, Immunoelectron; D009478:Neuropeptide Y / Q000032:analysis* / Q000276:immunology; D013569:Synapses / Q000737:chemistry / Q000648:ultrastructure; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D009478:Neuropeptide Y; D005680:gamma-Aminobutyric Acid