Aberrant prefrontal activity and arousal level correlate with action initiation and response vigor in rats

Orchestrating learned stimulus-response (S-R) mappings is a central function of the prefrontal cortex (PFC), as evidenced by S-R selective neuronal activity during correct task performance. During errors, the "wrong" neurons are aberrantly activated. While movement vigor has been related to basal ganglia neural activity, the neural correlates linking S-R mappings to vigor remain elusive. We trained male rats to perform a head-fixed Go/NoGo task on a treadmill, enabling the recording of PFC single-unit spiking and running speed. Aberrant activation of the "wrong" S-R mapping predicts the initiation of incorrect responses, and the vigor of those responses scales with the strength of the aberrant stimulus-evoked activity. We show that such responses occur in the context of heightened arousal, addressing a classic but under-tested hypothesis linking arousal to vigor. These findings directly relate S-R mappings to response vigor and show how arousal is co-modulated with this relationship.