Fig. 1

a Representative image of the site of optic nerve injury (ON-CR) relative to the site of tumor (optic glioma) formation. b Following optic nerve crush (ON-CR) at 6 weeks of age, Nf1^flox/flox; hGFAP-Cre mice have progressive loss of retinal ganglion cells (RBPMS⁺ cells) in the retina relative to those undergoing a sham operation (sham, n = 4; 1 wk, n = 4; 12 wk, n = 3). c Nf1^flox/flox; hGFAP-Cre mice are subjected to bilateral ON-CR, while control mice undergo a sham operation (incision without crush), at 6 weeks of age. Optic nerves are analyzed at 12 weeks of age. Nf1^flox/flox; hGFAP-Cre mice following ON-CR have increased d optic nerve volumes (n = 6) and e percentages of proliferating (%Ki67⁺) tumor cells relative to the sham operation group (n = 6). Immunohistochemistry shows an increase in f optic nerve cellularity (H&E positive cells) and g GFAP expression in Nf1^flox/flox; hGFAP-Cre mice following ON-CR compared to sham controls. Immunofluorescence microscopy reveals increased h %Olig2⁺ cells (sham, n = 6; ON-CR, n = 7) and i %Blbp⁺ cells (sham, n = 5; ON-CR, n = 5) in the optic nerves of Nf1^flox/flox; hGFAP-Cre mice following ON-CR compared with sham controls. j Following unilateral optic nerve crush (u-ON-CR) in Nf1^flox/flox; hGFAP-Cre mice at 6 weeks of age, the prechiasmatic region ipsilateral to the u-ON-CR exhibits greater j volume (n = 5) and k proliferation (%Ki67⁺ cells; n = 5) relative to the prechiasmatic region contralateral to the u-ON-CR at 12 weeks of age. Data are presented as the means ± SEM. Scale bars: b Upper panel scale bar, 500 µm; lower panel scale bar, 100 µm; d, j 100 µm; f, g Upper panel bar, 200 µm; lower panel scale bar, 50 µm; e, h, i 40 µm; k 200 µm, b, One-way ANOVA with Bonferroni post hoc correction; d, e, h, i, j, k, Two-tailed Student’s test