RESEARCH

​ Failure to stop ourselves from engaging in behaviors that are immediately rewarding- such as smoking, overeating, or spending- can lead to outcomes that are harmful to our health, finances, and relationships. These behaviors can be impulsive in that they are driven, without planning, in response to environmental cues associated with rewarding outcomes. They are often difficult to stop. We are interested in understanding the role of fronto-striatal circuitry in the successful inhibitory control over approach behaviors, as well as failures. Task manipulations, such as varying attentional load or the probability that a prepotent behavior will need to be stopped, enable parametric control of behavior.  We have found that cues leading to successful "stopping" of behavior drove increased levels of activity in the nucleus accumbens (NAc). The ability to stop is impaired by blocking excitatory signaling in the NAc. The medial prefrontal cortex (mPFC) is a potential source of these excitatory inputs. To test this possibility, we have found that pharmacological inactivation of mPFC and functional disruption of the connection between mPFC from NAc both impair stopping. These findings suggest that an excitatory projection from mPFC to NAc enables one to stop a prepotent behavior in response to environmental cues. We are using DREADDS to manipulate dopaminergic targets in mPFC in the control of impulsive action.