[The molecular basis for the protection and axon regeneration of motor neurons after nerve injury].

This review addresses the morphological changes seen in motor neurons and the surrounding non-neuronal cells in the process of regeneration after nerve injury. In addition, the molecular basis for the morphological changes and the gene expression regulation are also addressed. In the CNS, morphological changes of astrocyte and microglia are seen in response to nerve injury, which could be important for neuron survival. In the periphery Schwann cells, macrophages and endoneurial fibroblasts play crucial roles in proper nerve regeneration. For those cellular functions and behaviors, a significant number of mediators among those cells is expressed. In addition to thase intercellular signalings, the intracellular signaling in injured motor neurons is also crucial. In the injured motor neurons, their fate appears to be determined by a balance of the protection and death signals. To properly control expression of those signals, some regeneration-specific transcription factor complexes as well as the epigenetic regulators are emerging.