Tiny Brainstem Switch Triggers Week-Long Anxiety, Study Finds

Researchers pinpoint a small group of autonomic C1 neurons in the brainstem's RVLM that, when overactivated, drive prolonged anxiety via the PAG; brief activation causes acute fear, but sustained firing can keep anxiety alive for days. Blocking C1 neurons after traumatic stress prevented long-term anxiety without affecting immediate autonomic functions, highlighting a potential targeted therapy for anxiety disorders.