Nerve cells communicate with each other and with muscle cells at specialized regions called synapses. The transmitting cell is capable of converting an electrical signal into the release of a chemical signal, and the receiving cell responds to this chemical signal. Ion channels are membrane proteins that are essential both for sending and receiving these signals. The sodium channel is an ion channel permeable only to sodium ions and is concentrated in muscle membrane at the neuromuscular junction. Patch clamp electrophysiology confocal microscopy of sodium channels labeled with tagged antibodies, and molecular techniques will be used to study the development and regulation of sodium channels at the rat neuromuscular junction. In addition, experiments will be done to identify molecules, possibly released by the nerve, that are responsible for the aggregation and immobilization of sodium channels at the synapse. These studies will provide fundamental information on the development and regulation of molecules critical to synaptic transmission and neuromuscular function.
