Central Amygdala Somatostatin Neurons Gate Passive and Active Defensive Behaviors.

The ability to develop adaptive behavioral responses to threat is fundamental for survival. Recent studies indicate that the central lateral amygdala (CeL), in particular its somatostatin-expressing neurons, is crucial for both learning and the expression of defensive response. However, how exactly these neurons participate in such processes remains unclear. Here we show for the first time in behaving mice that the somatostatin-expressing neurons in the CeL acquire learning-dependent responsiveness to sensory cues predicting a threat. Furthermore, our results indicate that these neurons gate the behavioral output of an animal: whereas high activity in these neurons biases toward passive defensive responses, low activity in these neurons allows the expression of active defensive responses.