Expression of two neuronal nicotinic receptor subunits in innervated and denervated adult rat muscle.

The presence of transcripts coding for various alpha and beta subunits of neuronal acetylcholine receptors was investigated using polymerase chain reaction (PCR) on RNA extracted from innervated and denervated adult rat muscles. The results indicate that mRNAs coding for the neuronal alpha 4 and beta 2 subunits are expressed by adult muscles. Unlike avian embryonic muscle tissue, mRNA coding for alpha 7 and beta 4 subunit was undetectable. Denervation did not significantly modify the expression levels of the alpha 4 and beta 2 subunit-specific mRNAs. The results complement our previous immunohistochemical data and suggest that neuronal acetylcholine receptors are expressed by adult muscle tissue and may play a role in the control of muscle function.