Autoradiographic visualization of extrajunctional acetylcholine receptors in whole human biceps brachii muscle. Changes in amyotrophic lateral sclerosis.

The morphological distribution of acetylcholine receptors in the whole biceps brachii muscle from a patient with amyotrophic lateral sclerosis (ALS) and from a control patient was studied by in vitro autoradiography with 3H-alpha-bungarotoxin (alpha-Btx). In ALS, 3H-alpha-Btx binding occurred over the entire muscle, while in the control case the binding was restricted to the motor end-plate region.