Finally, to confirm that P110 treatment affected its target, we determined Drp1 association with the mitochondria in the three groups of mice. When we analyzed the spinal cord mitochondrial fractions after 24 days of treatment (mice age was 114 days), we observed about eightfold increase mitochondrial association of Drp1 in SOD1 G93A mice as compared with WT mice (P = 0.00012), which was significantly corrected (approximately 65% lower) following sustained P110 treatment (Fig 5G; P = 0.0017). Together, these results indicate that inhibiting Drp1 hyperactivation and increased association with the mitochondria by P110 treatment that began after disease onset reduced ALS‐related pathologies in this mouse model.