nAChRs are homopentameric or heteropentameric units that are localized primarily at presynaptic or preterminal sites, where they modulate neurotransmitter release. They are also found on cell bodies and dendrites, where they mediate postsynaptic effects. nAChRs have an important role in regulating transmitter release, cell excitability, and neuronal integration (Gotti and Clementi 2004; Hogg and Bertrand 2004; Hogg et al. 2003).
