|Budget Amount *help
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 1997: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥5,200,000 (Direct Cost: ¥5,200,000)
In order to identify nerve regeneration associated molecules, we have used a method called the differential display. We purified RNA from nerve injured-and normal hypoglossal nuclei respectively, and these RNAs were further processed for the differential display. The present method successfully demonstrated several candidate genes which were up-regulated after nerve injury. A screening using in situ hybridization histochemistry further squeeze the candidates. These are (1) molecules belonging to glutamate metabolism, (2) molecules implicated in free radical scavenger, (3) a certain group of growth factor receptors, (4) molecules along a certain intracellular signaling, and (5) molecules implicated in redox regulation. Since these molecules were derived from adult injured motoneurons which can survive even after nerve injury. We examined if these molecules were also respond to a similar type of nerve injury in new born motoneurons which were fated to die by nerve injury. Both adult and pups hypoglossal nerve were axotomized, and in situ hybridization was carried out to identify transcription regulations. In this comparison, we found that some molecules have an ability to respond to nerve injury in adult, but not in pups. For instance, LIF-R and GDNFR (alpha) respond to nerve injury positively in adult, but negatively in pups. This opposite responses to nerve injury may be a reason why adult motoneurons can survive and pup's motoneurons die after nerve injury.