Magazine article Science News

It Takes Nerve to Make Muscles Bond

Magazine article Science News

It Takes Nerve to Make Muscles Bond

Article excerpt

When first formed, muscles are useless. Before the body can command a muscle into action, intimate couplings must form between muscle cells and nerve cells. Scientists are now close to understanding the biochemical discourse that allows the cells to create such bonds, according to three reports published last week.

Researchers have long known that the so-called neuromuscular junction, a specialized structure similar to the synapses that link nerve cells in the brain, develops at a spot on the muscle determined by the nerve. "The nerve cell comes in and says, Do it here," explains Zach W. Hall, director of the National Institute of Neurological Disorders and Stroke in Bethesda, Md. A key element of the nerve cell's initial chat with a muscle cell appears to be a protein called agrin. Released by the nerve cell onto the muscle cell, agrin induces changes crucial to the construction of the muscle's side of a neuromuscular junction, including the clustering of proteins such as acetylcholine receptors, which recognizes the neurotransmitter released by the nerve cell.

Researchers have now confirmed agrin's importance by creating mice that can't make the protein. Such mice are dead at birth, never once breathing or moving, report Joshua R. Sanes of Washington University School of Medicine in St. Louis and his colleagues in the May 17 Cell.

As expected, agrin's absence leads to improper neuromuscular junction development, says Sanes' group. Yet other observed abnormalities, such as unusual growth of nerves, were not predicted and suggest that agrin's release also somehow affects nerve cells, says Sanes. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.