Changes in mitochondrial dynamics following NMN treatment in CA1 hippocampal neurons from CAMK-eYFP mice. Representative confocal images of control (A) and NMN-treated (B) neuronal mitochondria in the CA1 hippocampal sub-region. The fluorescent mitochondria appear more fragmented (see white arrows) in the control image compared to NMN treatment that clearly demonstrates more elongated mitochondria. Graphs (C, D) show the relative shape distribution and the relative mitochondrial length distribution (E, F) of different mitochondrial populations. Scale bar in panels (A) and (B) represents 5 μm. **p < 0.05; *p < 0.01.