Dorsal Periaqueductal gray ensembles represent approach and avoidance states

Animals must balance needs to approach threats for risk-assessment and to
avoid danger. The dorsal periaqueductal gray (dPAG) controls defensive
behaviors, but it is unknown how it represents states associated with
threat approach and avoidance. We identified a dPAG threat-avoidance
ensemble in mice (Mus musculus) that showed higher activity far from
threats such as the open arms of the elevated plus maze and a live
predator. These cells were also more active during threat-avoidance
behaviors such as escape and freezing, even though these behaviors have
antagonistic motor output. Conversely, the threat-approach ensemble was
more active during risk-assessment behaviors and near threats.
Furthermore, unsupervised methods showed approach/avoidance states were
encoded with shared activity patterns across threats. Lastly, the relative
number of cells in each ensemble predicted threat-avoidance across mice.
Thus, dPAG ensembles dynamically encode threat approach and avoidance
states, providing a flexible mechanism to balance risk-assessment and
danger avoidance.