Induction of acetylcholine receptors on cultured skeletal muscle by a factor extracted from brain and spinal cord.

Extracts of chicken brain and spinal cord increase the total number of acetylcholine receptors and the number of acetylcholine receptors and the number of receptor clusters on uninnervated skeletal myotubes in culture. The active component in these extracts may be unique to neural tissue. Spinal cord cells grown in culture contain the active factor and they secrete it into the medium. Most of the activity is associated with a small molecule possibly a peptide. Such a factor may be responsible for the clustering of receptors at newly formed nerve-muscle synapses.