SOD1 and amyotrophic lateral sclerosis: We exposed primaryrat ventral spinal cord neuronal cultures and rat spinal cord organotypiccultures to astrocyte-conditioned medium derived from primary mouseALS astrocytes expressing mutant human SOD1 (SOD1G93A-ACM)or from human-induced pluripotent stem cell (iPSC)-derived astrocytescarrying an ALS-causing mutation in SOD1 (SOD1D90A-ACM)or an ALS/FTD-causing mutation in TDP-43 (TDP43A90 V-ACM).