Autonomic nervous system transmission

Abstract

Rapid synaptic transmission within mammalian autonomic ganglia is mediated by nicotinic receptors (nAChRs) containing both the α3 and β4 subunits. Some nAChRs additionally have β2 or α5 subunits, and in embryonic chicken ciliary ganglia some nAChRs have all four subunits. While autonomic neurons express multiple α3-containing nAChR types, including ones that are expressed presynaptically on terminals, it is not known directly which forms are targeted to which domains of the cell. α7 nAChRs are expressed in both mammalian and embryonic chicken ganglia, but only in the chicken are they involved in synaptic transmission. The autonomic nervous system remains a good model system in which to study nAChR diversity as well as the properties of nAChRs derived from the CHRNA5/ A3/B4 cluster, which is linked to nicotine dependence.