In vivo imaging of the vesicular acetylcholine transporter and the vesicular monoamine transporter

Validation of the vesicular acetylcholine transporter (VAChT) and the neuro nal vesicular monoamine transporter (VMAT2) as important molecular targets in the cholinergic and dopamine neurons, respectively, has sparked interest in the development of radiotracers for studying these markers in vitro and in vivo. Currently, a number of selective high-affinity radiotracers are a vailable for studying these targets in vivo with positron emission tomograp hy (PET) or single photon emission computed tomography (SPECT), PET studies of VMAT2 in neuropathology reveal changes in the density of this marker th at can be verified independently. Similarly, in vivo studies with VAChT lig ands suggest that the latter are potentially useful in detecting cholinergi c lesions in vivo; however, additional development is required to fully rea lize the potential of these radioligands.