Action potentials in many types of excitable cells result from changes in permeability to Na ions. Although these permeability changes in nerve and muscle are mediated by voltage-gated Na channels that are functionally similar, we found that the Na-channel gene expressed in skeletal muscle is different from the genes coding for two Na channels (type I and type II) in brain. Despite the structural differences between muscle and brain Na-channel genes, a cDNA clone derived from rat brain hybridizes to skeletal muscle Na-channel mRNA of approximately 9.5 kilobases. We used this cDNA probe to measure changes in Na-channel mRNA levels in skeletal muscle during development and following denervation. By blot hybridization analysis of electrophoretically fractionated RNA, we found that Na-channel mRNA can be detected as early as embryonic day 17 and that mRNA levels increase 2-fold between birth and postnatal day 35. Denervation of adult muscle causes a further 2- to 3-fold increase in muscle Na-channel mRNA levels, suggesting that expression of Na-channel genes in fast-twitch muscle may be regulated by the state of innervation.
This research output has an Altmetric Attention Score of 6. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 06 September 2011.
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#7,582,167
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Outputs from Proceedings of the National Academy of Sciences of the United States of America
#63,366
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#6,404
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Outputs of similar age from Proceedings of the National Academy of Sciences of the United States of America
#105
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Altmetric has tracked 34,363,559 research outputs across all sources so far. This one has received more attention than most of these and is in the 73rd percentile.
So far Altmetric has tracked 118,931 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 40.1. This one is in the 37th percentile – i.e., 37% of its peers scored the same or lower than it.
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We're also able to compare this research output to 315 others from the same source and published within six weeks on either side of this one. This one is in the 43rd percentile – i.e., 43% of its contemporaries scored the same or lower than it.
