Fig. 3

Nicotinamide prevents mitochondrial cristae loss at an ultrastructural level. TEM imaging of retinal cross sections allowed for reconstruction of mitochondria in (A) the GCL and (B) the IPL. TEM imaging of optic nerve cross sections allowed for reconstruction of mitochondria in (C) the optic nerve. (A) in the GCL rotenone induced an increase in mitochondrial perimeter, but with a loss of internal cristae structure, which was protected against by NAM pretreatment. (B) In the IPL, mitochondria demonstrated a subtle increase in size following rotenone injury, with an increase in cristae surface area. However, this occurred in addition to a loss of mitochondrial integrity index supporting a disorganization and fragmentation of internal cristae structure. NAM treatment did not significantly overcome this, suggesting that NAM may exert more benefit at the soma than in the dendrites. (C) In the optic nerve, mitochondria became significantly smaller with a loss of cristae structure and integrity. NAM was able to significantly protect against this. Scale bar = 100 nm