measuring the β2-subunit in combination with α3-6 subunits leaving the in vivo measurement of the β3-subunit and α7-subunit for the future, with further radiotracer development. Both the α7- and β3-subunit have been implicated in modulating dopamine release14, 89 and thus, may also play a role in the rewarding properties of tobacco smoke. While the α7-subunit does not upregulate in response to chronic nicotine31, it is critically involved along with the β2-subunit in mediating desensitization/inactivation of the neuronal nAChRs in response to chronic nicotine90.
