CRHR1 and Anxiety: However, it is unlikely that the increased anxiety-like behavior observed in the F2 PNS males under basal conditions results from differential expression of CRH receptors in the BNST, since intra-BNST administration of specific antagonists for CRHR1 or CRHR2 has no effect on anxiety-like behavior in male rats under non-stress conditions (Sahuque et al., 2006).