The most prominent example of loss of normal astrocyte function in ALS is the marked downregulation of the astrocyte-specific glutamate transporter, GLT-1, in spinal cord of sporadic ALS patients and G93A mutant SOD1 transgenic mice and rats (Rothstein et al., 1992, 1995; Dunlop et al., 2003; Guo et al., 2010). Here, SOD1 is linked to amyotrophic lateral sclerosis.