Sympathetic neurons from the chick superior cervical ganglion (SCG) in culture synthesize and accumulate catecholamine (CA), and to a lesser extent, acetylcholine (AcCho). The noradrenergic and cholinergic properties of these cells can be differentially modulated by various external factors such as neuronal density, chick eye extract, liver-conditioned-medium, and inosine. We report here that forskolin, an activator of adenylate cyclase, selectively promotes AcCho, but not CA production in the chick SCG neurons. This effect is rapid since an increase in the AcCho content is already observed 60 min after the addition of forskolin to 2-week-old cultures. Rapid gene induction or protein phosphorylation via a cAMP-dependent pathway may thus be involved in the differential regulation of acetylcholine metabolism in cultured chick sympathetic neurons.