Fig. 1.
(A.) Effect of s.c. formalin or saline (administered 1 h after conditioning) on freezing in a test of conditioned fear to the conditioning contextual cues (CX) or to the tone conditioned stimulus (CS) when tested in a different context. Pre-CS refers to freezing prior to the CS being switched on in the CS test. (B) Effect of s.c. formalin when administered 0.5, 2, 8, or 32 h after conditioning on freezing in a test of conditioned fear to the conditioning contextual cues (CX) or to the tone conditioned stimulus (CS) when tested in a different context. Pre-CS refers to freezing prior to the CS being switched on in the CS test.