Fig. 7

Effects of PQQ administration on general and RGC-specific mitochondrial morphology in the optic nerve in vivo. A Representative images of optic nerve longitudinal sections from MitoV animals treated long-term with either vehicle or 20 mg/kg PQQ immunolabeled for TOMM20 (red). B–F Violin plots showing individual volume (B), surface area (C), sphericity (D), prolate (E) and oblate (F) of TOMM20-positive mitochondrial particles in optic nerves from vehicle- or PQQ-treated animals. n = 9338 vehicle and 9293 PQQ disconnected particles in 8 different optic nerves per group. G–I Averaged volume sum (G), surface area sum (H) and count (I) per optic nerve of TOMM20-positive particles. n = 8 optic nerves per group. J Representative images of optic nerve longitudinal sections from MitoV animals treated long-term with either vehicle or 20 mg/kg PQQ immunolabeled for YFP (an antibody anti-GFP was used to limit loss of signal from potential bleaching of YFP; the staining is indicated here as MitoV) (green). K–O Violin plots representing individual volume (K), surface area (L), sphericity (M), prolate (N), oblate (O) of MitoV-positive particles in optic nerves of vehicle and PQQ-treated animals. n = 4378 vehicle and 3947 PQQ disconnected particles in 8 different optic nerves per group. P–R Averaged volume sum (P), surface area sum (Q) and count (R) per optic nerve of MitoV-positive particles. n = 8 optic nerves per group. For individual parameters, individual values of disconnected particles from each optic nerve were analyzed together and a linear mixed effects model was applied to account for the multiple observations that come from the same sample. Scale bar = 20 μm. The red zoom depicts the inset of data points to optimally visualize the data distribution. *p < 0.05 and **p < 0.01 versus vehicle