Role of innervation on the embryonic development of skeletal muscle.

摘要: The extent to which the motor innervation regulates embryonic development of skeletal muscle was investigated by comparing changes in normal, aneural, and paralyzed superior oblique duck embryo. made aneural permanently destroying trochlear neurons with electrocautery on day 7 i.e., three days prior innervation. Embryos were daily application α-bungarotoxin onto chorioallantoic membrane from 10 onwards. differentiation myoblasts myotubes severely affected did not progress myofiber stage. A mass dead cells replaced connective tissue. Although also retarded muscle, numerous progressed Neuromuscular junctions normal ultrastructure seen all muscles. Degeneration some occurred but there no evidence a massive wave cell death similar that observed muscle. These observations suggest both trophic factors nerve nerve-evoked activity are essential for execution developmental program Trophic may play larger role differentiation, maintenance than activity.