Subsecond Ensemble Dynamics of Orexin Neurons Link Sensation and Action

Hypothalamic hypocretin/orexin neurons have been initially conceptualized as slow, modulatory controllers of behavior. Furthermore, their behavioral effects assumed to be a secondary consequence impact on arousal. However, cellular-resolution calcium imaging and optogenetic studies show that orexin regulate self-generated sensory-evoked movement rapid, subsecond timescales. Orexin cell activity rapidly transiently peaks before during movements. Optogenetic prevention this activation reduces the probability locomotion initiation, mimicry causes locomotion. Neural ensemble experiments reveal same cells whose underlies initiation display subsecond-latency responses diverse sensory stimuli. These findings establish rapid strong sensorimotor are in many ways operationally similar classic subcortical controllers, such midbrain dopamine neurons. While scientific definition “arousal” is still lacking, subsecond-scale control by could viewed reminiscent motor rather than an arousal system.