Figure 6From: Muscarinic signaling influences the patterning and phenotype of cholinergic amacrine cells in the developing chick retinaMuscarinic signaling influences the phenotype and density of cholinergic amacrine cells in the intact retina. Confocal microscopy was used to obtain optical sections of flat-mounted retinas labeled with antibodies to ChAT (green) and CRABP (red). Optical sections were obtained at the level of the developing IPL to visualize the type-II cells. Images are shown from retinas treated with saline (a-c) or atropine (d-f). The arrows indicate type-II cells that are immunoreactive for ChAT and CRABP, and the arrow-heads indicate cells that are immunoreactive for ChAT alone. Panel g is a histogram of the percentage of type-II cholinergic cells in the IPL that are immunoreactive for CRABP. Cells were counted from retinas that were treated with saline, atropine or carbachol. Panel h is a histogram of the number of ChAT-immunoreactive cells in the INL (type-I) and presumptive IPL (type-II) in retinas treated with saline, atropine or carbachol. The significance of difference was assayed by using ANOVA (p < 0.02) and a post-hoc Student's t-test (2 tailed, equal variance; *p < 0.05, **p < 0.025, ***p < 0.002). Panels i-m are representative microgrographs of retinal sections labeled for cleaved caspase 3 (green; i-k) and Islet1 (red; i) or CRABP (red; j and k), Brn3a (l), and calretinin (m). The calibration bar (50 μm) in panel f applies to panels a-f, the bar (50 μm) in i applies to i alone, the bar (10 μm) in k applies to j and k, and the bar (50 μm) in m applies to l and m. Abbreviations: INL – inner nuclear layer, IPL – inner plexiform layer, ChAT – choline acetyltransferase, CRABP – cellular retinoic acid binding protein.Back to article page