Targeting alpha7-containing nicotinic receptors on neurons to distal locations

Nicotinic receptors containing the alpha7 gene product are widely expressed in the nervous system and have a high relative permeability to Ca(2+). This permits them to influence a variety of Ca(2+)-dependent events in neurons. On chick ciliary ganglion neurons, the receptors are concentrated on somatic spines and contribute directly to postsynaptic signaling. Receptors containing the alpha7 gene product can also be found in the chick sciatic nerve being transported to distal locations. Both motoneurons and dorsal root ganglion neurons are candidate sources of the receptors since both extend processes into the nerve and synthesize alpha7 protein. Immunoprecipitation assays with subunit-specific monoclonal antibodies and pharmacological comparisons fail to detect differences between sciatic nerve and ciliary ganglion alpha7-containing receptors. Cell-specific machinery and receptor posttranslational modifications may determine which sites the receptors populate.