In fact, post-mortem analysis of spinal cords obtained from ALS patients have demonstrated a decreased amount of NT-3 and BDNF in spinal motoneurons (Duberley et al., 1997; Nishio et al., 1998), as well as an increase in the quantity of non-phosphorylated TrkB (Mutoh et al., 2000), pointing to a diminution in trophic signaling in degenerating motoneurons during ALS progression in humans. This evidence concerns the gene NTF3 and amyotrophic lateral sclerosis.