(a) Effect of clonidine on CRF-induced increases in startle in Block 1. Clonidine reversed the startle increase in oCRF treated mice (*p<0.05, oCRF/Veh versus all other groups, post-hoc test). (Inset) Effect of clonidine on CRF-induced increases in startle across the test session. oCRF-induced increases in startle during Blocks 1 and 2 was significantly blocked by clonidine treatment (*p<0.05, oCRF/Veh versus all other groups, post-hoc test). (b) Effect of prazosin on CRF-induced increases in startle in Block 1. Prazosin reversed the startle increase in oCRF treated mice (*p<0.05, oCRF/Veh versus. all other groups, post-hoc test). (Inset) Effect of prazosin on CRF-induced increases in startle across the test session. oCRF-induced increases in startle were significantly blocked by prazosin in Blocks 1 and 2 (*p<0.05, oCRF/Veh versus all other groups, post-hoc test. Startle magnitude in the oCRF/Veh group remained significantly higher compared to Veh/Veh and Veh/Prazosin during Block 5 (+p<0.05, oCRF/Veh versus Veh/Veh, Veh/Prazosin, post-hoc test). (c) Effect of propranolol on CRF-induced increases in startle in Block 1 (*p<0.05, main effect of oCRF). (Inset) Effect of propranolol on CRF-induced increases in startle across the test session. Although oCRF increased startle magnitude, this effect was not reversed by propranolol during any block (*p<0.05, main effects of oCRF, see text for details).