When ARIA isolated from chick embryo brain was applied to chicken myotubes it was shown to increase the rate of insertion of acetylcholine receptors into chicken myotube membranes .
Chicken myotubes are developing chicken muscle fibers .
When ARIA isolated from chick embryo brain was applied to chicken myotubes , which are developing chicken muscle fibers , it was shown to increase the rate of insertion of acetylcholine receptors into chicken myotube membranes .