Developmental changes and strain difference of CRHR1 and CRHR2 mRNA at the BBB level in C57 and Avy mice (n = 3/group). *, P < 0.05, **, P < 0.01 when the neonates and adults from the same strain are compared. A, There were significant effects of age and Avy mutation on CRHR1. In both B6 and Avy mice, neonates had higher levels of CRHR1 than adults. The Avy neonates had a lower level of CRHR1 than B6 neonates. B, There was a strain effect (P < 0.05) and only a trend toward an effect of age (P = 0.067) for CRHR2.