Neurotrophin-4 (NT-4) and glial cell line-derived neurotrophic factor (GDNF) promote the survival of corticospinal motor neurons of neonatal rats in vitro.

We have used enriched dissociated, low density cultures of neonatal rat corticospinal motor neurons to evaluate the survival-promoting effect of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), neurotrophin-4 (NT-4), and glial cell line-derived neurotrophic factor (GDNF) and the ciliary neurotrophic factor (CNTF). Our current findings demonstrated that CNTF promoted the survival of corticospinal motor neurons, in the same fashion and at an equivalent potency, as was previously described using a different assay system. Among the other factors tested, we also found that NT-4 and GDNF increased the number of surviving neurons in a dose-dependent manner, whereas NGF, BDNF and NT-3 showed no survival promoting effect on corticospinal motor neurons.