In order to gain a deeper understanding of how changes in neuromorphology and synaptic loss relate to disease progression in ALS/FTD, we generated a neuron-specific FUS-transgenic mouse, hFUSR521G/Syn1, and longitudinally assessed these pathological features and their relationship to other ALS/FTD-associated phenotypes. The gene discussed is FUS; the disease is amyotrophic lateral sclerosis.