Fig. 2

Immunostaining against choline acetyltransferase (ChAT) in wholemount retinas of control and PD patients. a–d Stack images of representative central and peripheral areas of a retinal wholemount containing both the INL and GCL. a, b A decrease in the total number of both ChAT-positive cell types: bright (arrowheads) and dim (arrows) could be observed in the central retina in PD compared to control. c, d The same result could be observed in the peripheral retina. A decrease in the ChAT plexus density in the S2 (e, f) and in the S4 (g, h) strata of the IPL could be observed in the PD retinas compared to controls. i–l Quantification of the total number of ChAT-positive cells in the INL (i), the number of bright (j) and dim (k) ChAT-positive cells in the INL, and the number of ChAT-positive cells in the GCL at 2, 4, 6, 8, 10, 12, 14 and 16 mm from the optic nerve to the inferonasal quadrant in control (n = 8) and PD retinas (n = 8). Results are presented as mean value ± SEM. Two-way ANOVA with Sidak’s multiple-comparison test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. ON optic nerve. Scale bars: 40 μm (a–d). 20 μm (e–g)