Anterior horn region of lumbar spinal cord sections from mice at 220 days. Motor neuron choline acetyltransferase (ChAT) positive cells (A-C, arrows) co-localized with SOD1 positive staining (D-F, arrows). H46R/H48Q mice exhibited small intracellular peri-nuclear SOD1 reactive punctae (E, arrows), while H46R/H48QxHSF1 tissues had a more even intracellular distribution of SOD1 staining (F). This corresponded with differences in HSP70 distribution to SOD1 reactive punctae in H46R/H48Q mice (H) while in contrast, co-localization with ChAT reactive cells in H46R/H48QxHSF1 mice was stronger (I). Scale bar represents 10 μm.