Optogenetic and pharmacological interventions link hypocretin neurons to impulsivity in mice

Neurons in the lateral hypothalamus expressing the neuropeptide Hypocretin, also known as orexin, are known critical modulators of arousal stability. However, their role in the different components of the arousal construct such as attention and decision making is poorly understood. Here we studied Hypocretin neuronal circuit dynamics during stop action impulsivity in a Go NoGo task in mice. We show that Hypocretin neuronal activity correlates with anticipation of reward. We assessed the causal role of Hypocretin neuronal activity using optogenetics in a Go/No Go task. We show that stimulation of Hypocretin neurons during the cue period dramatically increased the number of premature responses. These effects were mimicked by amphetamine, reduced by atomoxetine, a norepinephrine uptake inhibitor, and blocked by a Hypocretin receptor 1 selective antagonist. We conclude that Hypocretin neurons have a key role in the integration of salient stimuli during wakefulness to produce appropriate and timely responses to rewarding and aversive cues.