Spatial distribution and size of acetylcholine receptor clusters determined by motor nerves in developing chick muscles

Publisher Website
Google Scholar
Abstract
Summary The size and distribution of acetylcholine receptor clusters (AChR-C) on normal and aneural developing muscle fibres of the chick wing were studied by labelling AChR with fluorescent conjugates of α-bungarotoxin (α-BGT). AChR-C of a size typical of initial synaptic contacts (5 μm long) were present at 7 days incubation, shortly after the appearance of nerves, and were grouped in bands corresponding to muscle nerve branches. A regular distribution of large (≅ 5 μm) AChR-C separated by 100–200 μm had developed by 10–14 days in the slow-tonic anterior latissimus dorsi and ulnimetacarpalis dorsalis muscles. The role of motor innervation in the formation of AChR-C was assessed by removing the brachial neural tube at 2 days incubation in order to prevent nerves entering the wing. Neural-tube removal prevented the appearance of the large AChR-C normally associated with the early synaptic contacts. Small AChR-C (< 2 μm long) appeared in aneural muscles, but these were not grouped into bands characteristic of the large AChR-C in normal muscles. The results suggest that the formation of junctional AChR-C is dependent on nerves.

This publication has 36 references indexed in Scilit: