Quantitative study of motor endplates in muscle fibres dissociated by a simple procedure.

Large numbers of single muscle fibres can be obtained reproducibly from glutaraldehyde-fixed skeletal muscle by the method described here. With suitable modifications, one can estimate acetylcholine receptor number (alpha-bungarotoxin binding sites) and endplate area in parallel portions produced from the same muscle sample, so that small differences (e.g. with growth or between muscle types) become detectable. Microdissection further increases the precision of evaluation of junctional, perijunctional and extrajunctional binding sites. Other applications are illustrated.