This research will focus on the distribution of ion channels in skeletal muscle and the mechanisms for creating and maintaining these channel distributions. The distribution and single channel properties of voltage-gated sodium channels will be studied with loose patch and tight patch voltage clamp. A new technique which combines both patch voltage clamp and ionophoresis will be used to find the degree of colocalization of sodium channels and acetylcholine receptors. Different distributions of sodium channels in fast and slow muscle may suggest functional roles for these channel distributions. Potassium channel and choride channel distributions will be studied with the same techniques since there is evidence that these too are nonuniformly distributed in muscle. The pertinence of extending these studies to other channels is that the channels are not regulated in unison either spatially or in response to perturbations. Thus it may be possible to identify both general and specific regulatory controls. Extracellular factors that may regulate channel distribution or immobilization will be tested.
