Risk reshapes amygdala representation of choice

Modifying behavior in response to changing environmental conditions is a crucial adaptive function. This capacity is evident when animals curtail the pursuit of a valued outcome that risks being punished, but the mediating brain mechanisms remain poorly understood. Here, using in vivo cellular-resolution calcium (Ca²⁺) imaging, optogenetics, and chemogenetics, we show that punishment risk dramatically alters choice between a large/risky and small/safe reward and produces novel, causally necessary patterns of activity in basolateral amygdala (BLA) neurons of male mice. We find that punishment generates a BLA representation that is reactivated when mice execute or abort the choice of a large/risky reward option. Additionally, we show that risk leads to the incorporation of newly encoding BLA neurons into the pre-choice representation and that this modification predicts avoidance of the large/risky option. Collectively, these findings reveal how dynamic reshaping of choice-related BLA representations underpins behavioral flexibility in the face of risk.