Hippocampal pathology is well documented in ALS patients primarily at later stages of disease [3, 20, 33–35] and a recent experimental study also demonstrated significant neuronal loss and atrophy of the hippocampus, after intracranial injection of recombinant adeno-associated virus serotype 9 containing human wild-type TDP-43, into the hippocampus of CAMKII-tTa transgenic mice [36]. Here, TARDBP is linked to amyotrophic lateral sclerosis.