[Implication of growth factor receptor signaling for axotomized motor neuron survival after nerve injury]

Motor neurons are able to survive even after nerve injury. In order to reveal the molecular basis underlying this survival mechanism, we carried out gene screening using Differential Display PCR method and a cDNA library derived from rat injured hypoglossal nuclei. This gene hunting provided us with some of the parts of the molecular mechanism for nerve regeneration, among which intracellular signaling molecules, in particular downstream growth factor receptors, seemed very important. We therefore examined the significance of the molecules by using adenovirus mediated gene transfer system, and concluded that PI3K-Akt pathway could be one of the important pathways by which injured motor neurons survive and regenerate.