Wallerian DegenerationNicotinamide-Nucleotide AdenylyltransferaseSciatic NerveNerve DegenerationAxonsAxotomyMyelin SheathSciatic NeuropathySchwann CellsInfarction, Anterior Cerebral ArteryPeripheral NervesNerve CrushOptic NerveNerve RegenerationPeripheral Nerve InjuriesPyramidal TractsTrauma, Nervous SystemElectrophysiological ProcessesNerve Fibers, MyelinatedNeurofilament ProteinsMice, Neurologic MutantsRetinal DegenerationMacular DegenerationSpinal Nerve RootsNerve Tissue ProteinsGanglia, SpinalPeripheral Nervous SystemDiffusion Magnetic Resonance ImagingMice, Inbred C57BLMotor NeuronsDemyelinating DiseasesNeuromuscular JunctionNerve FibersSpinal Cord InjuriesMicroscopy, ElectronSpinal Cord