Differential survival response of neurons to exogenous GDNF depends on the presence of skeletal muscle.

Glial cell line-derived neurotrophic factor (GDNF) is known as a potent survival factor for neurons in vitro and in vivo. The current study investigated the effects of a single in utero injection with GDNF in both wild-type and Myf5-/-:MyoD-/- embryos. The embryos in the latter group, denoted double mutants (DM), do not contain skeletal muscle and associated neurotrophic factors due to lack of myogenesis and, therefore, neurons of the central and peripheral nervous system undergo excessively occurring programmed cell death (EPCD).

Subpopulations of motor and sensory neurons respond differently to brain-derived neurotrophic factor depending on the presence of the skeletal muscle.

The aim of our study was to assess the ability of brain-derived neurotrophic factor (BDNF) to rescue motor and sensory neurons from programmed cell death. It is clearly demonstrated that the administration of a single injection of a putative neurotrophic factor to mouse embryos in utero on embryonic day (E) 14.5 is sufficient to significantly reduce the death of motor neurons when assessed on E18.