INCREASED TRKB MESSENGER-RNA EXPRESSION BY AXOTOMIZED MOTONEURONS

IT has been previously demonstrated that members of the neuroptrophin family way prevent death of motoneurones following axotomy. Here we re port that the expression of mRNA for full-length trkB, which is a sign al transducing receptor for BDNF and NT4, increases transiently in spi nal motoneurones after axotomy in adult rats. Thus, transection of the sciatic nerve resulted in markedly increased levels of trkB mRNA in a xotomized motoneurones three days postinjury, while the levels had ret urned to normal within three weeks. The data support that neurotrophin s may be important for survival and/or regeneration of motoneurones af ter axon lesion.