Light- and electron-microscopic analysis of neuropeptide Y-immunoreactive amacrine cells in the guinea pig retina.
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.
Kang
W S
WS
Department of Biology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
Lim
M Y
MY
Lee
E J
EJ
Kim
I B
IB
Oh
S J
SJ
Brecha
N C
NC
Park
C B
CB
Chun
M H
MH
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
D000911:Antibodies, Monoclonal; D009478:Neuropeptide Y; D005680:gamma-Aminobutyric Acid