A MeA Tac1 neural circuit mediates anxiety-like behaviors in mice.

Anxiety is an emotion characterized by worried thoughts and feelings of unease, often accompanied by physical symptoms such as sweating and dizziness. Unlike other negative emotions, the neural circuits underlying anxiety are not well understood. Here we report that Tachykinin Precursor 1 (Tac1)-expressing neurons in the medial amygdala (MeA) respond to the transition from high anxiety to low anxiety states. The MeATac1 neurons regulate anxiety-like behaviors in mice bidirectionally. We also show that GABAergic neurons in the ventral tegmental area (VTA)→MeA→ventrolateral part of the ventromedial hypothalamic nucleus (VMHvl) circuit contribute to anxiety-like behavior in mice. Our findings reveal a circuit of Tac1 neurons in the MeA that mediates anxiety-like behaviors in mice.