Localization of serotoninlike-immunoreactive amacrine cells in the larval tiger salamander retina.
Light microscopic immunocytochemistry was used to study the populations of serotoninlike-immunoreactive cells in the larval tiger salamander retina. Of 1,135 serotonin-immunostained cells observed in transverse cryosections, 87% were identified as amacrine cells, whereas 13% were tentatively designated as displaced amacrine cells. The somas of the vast majority of serotonin-amacrine cells were situated in the innermost cell row of the inner nuclear layer. Only a few serotonin-immunostained amacrine cell somas were observed in the second row of cells from the inner nuclear layer. Serotonin-immunoreactive processes generally appeared as a diffuse plexus distributed evenly throughout all levels of the inner plexiform layer. As determined in whole-mount preparations, serotonin-amacrine cells were divisible into two populations on the basis of the diameters of their somas. Large cells (45%) ranged from 16 to 19 microns in diameter with the vast majority measuring 17-18 microns. Smaller and sometimes less intensely stained cells ranged from 14 to 16 microns in diameter with the large majority measuring 15 microns. The diameters of serotonin-displaced amacrine cells ranged from 19 to 22 microns with the large majority measuring 20 microns in diameter. An examination of whole-mount retinas revealed that serotonin-immunoreactive amacrine and displaced amacrine cells were distributed throughout the center and the periphery of the retina. The density of serotonin-amacrine cells (large and small combined) was calculated to be 173 +/- 4.5 (mean +/- standard error) cells per mm2.
Yang
S Z
SZ
Alice R. McPherson Laboratory of Retina Research, Center for Biotechnology, Baylor College of Medicine, The Woodlands, Texas 77381.
Lam
D M
DM
Watt
C B
CB
D000818:Animals; D001345:Autoradiography; D007150:Immunohistochemistry; D012160:Retina / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D012701:Serotonin / Q000276:immunology / Q000378:metabolism*; D013194:Staining and Labeling; D014562:Caudata / Q000378:metabolism*
D012701:Serotonin