Fig. 1

Significantly reduced RGC numbers in 3- and 7-month-old BDNF knockout mice. (A): Retinal cross-sections of 3-month-old mice were stained with an antibody against the RGC-specific marker RBPMS (red), and cell nuclei were stained with DAPI (blue). (B): In 3-month-old animals, the number of RBPMS⁺ cells in the central retina of CLF and LF mice were significantly lower compared to controls (both: p < 0.001). (C): Also, in the peripheral part, a significant RGC loss was observed in CLF and LF mice (both: p < 0.001). (D): Cell counting in the total retina revealed a significant loss of RGCs in both knockout groups (both: p < 0.001). (E): Pou4f1 mRNA expression was significantly downregulated in the LF group (p < 0.050). The relative expression of Pou4f1 in the CLF group showed no differences. (F): Retinal cross-sections of 7-month-old mice were stained with anti-RBPMS (red) and cell nuclei with DAPI (blue). G: In the central part of the retina, the number of RGCs was significantly lower in CLF and LF mice compared to controls (both: p < 0.010). (H): Lower RGC numbers were also noted in the peripheral retina in 7-month-old CLF as well as LF animals (both: p < 0.050). (I): Cell counting in the total retina revealed significantly fewer RGC in the BDNF knockout groups (both: p < 0.001). (J): Relative Pou4f1 mRNA expression was significantly downregulated in CLF and LF mice (both: p < 0.010). Values in B-D and G-I are mean ± SEM and each symbol depicts an individual data point. Values in E + J are median ± quartile ± min/max and the dotted lines represent the relative expression of the controls. GCL: ganglion cell layer, IPL: inner plexiform layer, INL: inner nuclear layer. *p < 0.050, **p < 0.010, ***p < 0.001. Immunhistological data was analyzed by ANOVA followed by Tukey Honest post-hoc test with n = 6 retinas/group/age, RT-qPCR data was assessed via Pair Wise Fixed Reallocation Randomisation Test© with n = 4–5 samples/group/age. Scale bars = 20 μm.