Dopamine receptors appear to do more than trigger pleasure. Based on new research, there are three different subtypes; each subtype reacts distinctly to either satisfying experiences (which we knew), unpleasant stimuli, or changes in speed of movement, thus providing
new insight into Parkinson’s. See:
The authors establish a connection between functional subtypes and genetic subtypes of dopamine neurons in mice and demonstrate that molecular expression patterns can serve as a common framework to dissect dopaminergic functions.