LMC and MMC motor neurons show similar patterns of trophic factor responsiveness. Slices were prepared from the lumbar enlargement and thoracic cord of the same mice to establish the respective trophic requirements of LMC and MMC neurons.A, Mirroring the situation in the LMC, BDNF, and CNTF supported the survival of a proportion of MMC motor neurons.B, Similarly, GDNF was the only GFL to exert a trophic effect on MMC neurons. Note that the absolute number of MNs in the thoracic MMC is significantly less than in the lumbar LMC (5.0 ± 0.8 vs 11.6 ± 0.8 neurons per section; p < 0.001). *p < 0.05; **p < 0.01; ***p < 0.001. 0, No trophic factor; G, GDNF; B, BDNF;C, CNTF; N, neurturin; A, artemin; P, persephin.