Muscle denervation increases thyrotropin-releasing hormone (TRH) biosynthesis in the rat medullary raphe.
To determine whether thyrotropin-releasing hormone (TRH) could exert a trophic role in ventral horn motor neurons, we examined the effect of muscle denervation with botulinum toxin A on TRH mRNA in the rat medullary raphe by in situ hybridization histochemistry. Compared to controls, denervated rats showed a significant increase in the number and silver grain density of hybridized medullary raphe neurons. Increased proTRH gene expression in the medullary raphe in response to motor unit perturbation indicates that TRH may be trophic to lower motor neurons.
Van den Bergh
P
P
Service de Neurologie, Université Catholique de Louvain, Brussels, Belgium.
Octave
J N
JN
Lechan
R M
RM
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001345:Autoradiography; D001905:Botulinum Toxins / Q000633:toxicity; D008297:Male; D008526:Medulla Oblongata / Q000378:metabolism*; D009043:Motor Activity / Q000187:drug effects; D009121:Muscle Denervation; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011903:Raphe Nuclei / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013462:Sulfur Radioisotopes; D013973:Thyrotropin-Releasing Hormone / Q000096:biosynthesis* / Q000235:genetics
D012333:RNA, Messenger; D013462:Sulfur Radioisotopes; D013973:Thyrotropin-Releasing Hormone; D001905:Botulinum Toxins