EXPRESSION OF NEUROTROPHIC FACTORS RELATED TO PLASTICITY OF MOTONEURONS

点击翻译按钮获取中文摘要

Motoneurons of the spinal nucleus of the bulbocavernosus of male rats innervate the perineal striated muscles bulbocavernosus and levator ani that attach to penis. They have an important role in copulatory behavior, which is sensitive to alterations in circulating levels of androgen. The perineal motoneurons are thought to be regulated by muscle-derived neurotrophic factors. To clarify regulatory mechanisms of muscle-derived neurotrophic factors, we examined expression of neurotrophic factors such as brain-derived neurotrophic factor (BDNF), neurotropnin-3 (NT-3), ciliary neurotrophic factor (CNTF) and insulin-like growth factor-1 (LGF-1) by immunohistochemistry and in situ hybridization. For immunohistochemistry, anti-BDNF,-NT-3,-CNTF and -IGF-1 were used, and for in situ hybridization, cDNAs for BGNF, NT-3,CNTF and IGF-1 were used. CNTF and NT-3 immunoreactivity was not detected in the bulbocarvenosus muscles. BDNF and IGF-1 immunoreactivtiy was partially detected in them. mRNA of NT-3 expressed in the muscle cells and fibroblasts of endomysium of the bulbocavernosus muscles. However, mRNAs of CNTF, IGF-1 and BDNF were not expressed in both of them. These results seem to indicate that mRNA of NT-3 expresses in the bulbocavernosus muscles although NT-3 is not detected in them by immunohistochemistry.