We have examined the regulation of neuronal nicotinic ACh receptor (nAChR) genes and ACh-evoked currents by neonatal rat sympathetic neurons developing in culture. These neurons contain 5 nAChR transcripts: a3, q, OL,, p2, and p,,. When developing in culture, the neurons express 4 of these transcripts, (Ye, 01~, p2, and p4, at levels similar to those in neurons developing in viva: cy3 mRNA leve...