Voluntary exercise increases neurotrophin-3 and its receptor TrkC in the spinal cord.
We have evaluated changes in the expression of neurotrophin-3 (NT-3) and its tyrosine kinase C (TrkC) receptor in the neuromuscular system as a result of voluntary physical activity. We assessed changes in the mRNAs and proteins for NT-3 and TrkC in the lumbar spinal cord and associated soleus muscle following 3 and 7 days of voluntary wheel running. We used quantitative Taqman RT-PCR to measure mRNA and ELISA to assess protein levels. NT-3 mRNA and protein levels increased in the spinal cord to reach statistical significance after 7 days of exercise compared to sedentary control rats. Immunohistochemical analyses localized the elevated NT-3 to the substantia gelatinosa (SG) and nucleus of the dorsal horn. TrkC mRNA levels were significantly elevated in the spinal cord after 3 and 7 days of running. In the soleus muscle, NT-3 mRNA levels and its receptor TrkC were elevated after 3 days, while NT-3 protein levels remained unaffected. The results demonstrate that voluntary exercise has a differential effect on NT-3 as well as its receptor TrkC in the neural and muscular components of the neuromuscular system, and emphasize the role of voluntary activity on the spinal cord and muscle.
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D008297:Male; D009043:Motor Activity; D020933:Neurotrophin 3 / Q000235:genetics / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D005082:Physical Exertion; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020812:Receptor, trkC / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism*; D015854:Up-Regulation
D020933:Neurotrophin 3; D012333:RNA, Messenger; D020812:Receptor, trkC
Non-programmatic