A maturational increase in rat neuromuscular junctional acetylcholine receptors despite disuse or denervation

Junctional acetylcholine receptors (AChR) of rat skeletal muscles were microassayed 4-7 days after denervation or total disuse. The normal growth-related increase in AChR number occurred despite denervation or muscle atrophy, but in disused muscles, this increase was less. Thus, at least for short periods, the developmental addition of junctional AChR is independent of muscle fiber size or innervation and partly independent of usage.