SMA mice were treated with intrathecal injections of ALDH^hiSSC^lo stem cells or vehicle on day P1. (A) Photographs showing the gross appearance of an NSC-treated SMA mouse (SMA Tr), an untreated SMA mouse (SMA), and a WT mouse. The treated SMA mice were larger than the untreated mice. (B) Kaplan-Meier survival curves of SMA mice treated with “primed” NSCs (SMA Tr), undifferentiated ALDH^hiSSC^lo cells (SMA NSC), ALDH^hiSSC^lo-derived astrocytes (SMA Astro), and primary fibroblasts (SMA Fibro) or untreated mice (SMA; n = 24 for each group). Survival was significantly extended for mice transplanted with primed NSCs compared with undifferentiated NSCs (P = 0.002, log-rank test); astrocytes and fibroblasts (P < 0.00001); or vehicle (P < 0.00001, log-rank test). (C) Weight curves of SMA ALDH^hiSSC^lo treated mice (n = 24) or untreated (n = 24) and unaffected littermate WT controls (n = 24). All plots show means of weight at each day, with error bars representing SD. Treated SMA mice displayed an increased growth rate with respect to untreated SMA mice (10–13 days; P < 0.00001). (D) Grip time in treated SMA mice (n = 24) or untreated SMA (n = 24) and unaffected littermate WT controls (n = 24). The grip time was statistically different in the untreated and treated SMA mice (P < 0.00001) at 12–13 days of age. Error bars represent SD.