CCKBR and Anxiety: Also repetitive intracerebroventricular injections of cortagine, a CRF1 agonist, increases CCK mRNA as well as CCKB protein expression in the mouse amygdala and hippocampus resulting in heightened anxiety behavior as assessed using the elevated plus maze and open field test, an effect reversed by intracerebroventricular injection of the CCKB antagonist, LY225910 (146).