CRHR2 and Anxiety: The study also found that mice with repeated exposure to a series of traumatic electric shocks showing PTSD-like phenotypes had long-term and continuous up-regulation of CRF2R mRNA in BNST, while CRF2R gene knockout in the posteromedial BNST prevented the development of PTSD-like features, which confirmed the bidirectional nature of CRF1R and CRF2R responses in anxiety and pain perception models.