Development of Excitability in Embryonic Muscle Cell Membranes in Certain Tunicates

Abstract
During the course of development of muscle cells in certain tunicates, a sign of regenerative membrane response appears in the gastrula stage. In the early tadpole larva, the action potential consists of a spike followed by a plateau. The latter-disappears in fully differentiated cells, conceivably in association with the establishment of delayed rectification.