Unique functional responses differentially map onto genetic subtypes of dopamine neurons

Abstract

Dopamine neurons are characterized by their response to unexpected rewards, but they also fire during movement and aversive stimuli. Dopamine neuron diversity has been observed based on molecular expression profiles; however, whether different functions map onto such genetic subtypes remains unclear. Here, we establish that three genetic dopamine subtypes within the substantia nigra pars compacta each have a unique set of responses to rewards, aversive stimuli, accelerations and decelerations, and these signaling patterns are highly-correlated between somas and axons within subtypes. Remarkably, reward responses were not detected in one subtype, which instead displayed acceleration-correlated signaling. Our findings establish a connection between functional and genetic dopamine subtypes and demonstrate that molecular expression patterns can serve as a common framework to dissect dopaminergic functions.