Fig. 3.

GDNF promotes the survival of an equivalent number of MNs as bax deficiency. A, Slices were cultured for 6 d in the presence or absence of GDNF (200 ng/ml) from animals homozygous for a deletion in the proapoptotic Bcl-2 family member bax (bax^−/−) and cultured alongside slices from wild-type littermates. MNs from bax^−/− cords survived 6 DIV in the absence of GDNF. The addition of GDNF did not further increase the number of MNs surviving in the bax^−/− cords. Absolute unilateral LMC counts are presented for each genotype. B, Expressed as a percentage of the neurons in fresh cord, the same proportion of wild-type MNs survived in the presence of GDNF as bax^−/− MNs both in the presence and the absence of trophic factor. No TF, No trophic factor. **p < 0.001.