Wa. Falls et al., LESIONS OF THE PERIRHINAL CORTEX INTERFERE WITH CONDITIONED EXCITATION BUT NOT WITH CONDITIONED INHIBITION OF FEAR, Behavioral neuroscience, 111(3), 1997, pp. 476-486
Posttraining lesions of the perirhinal cortex (Prh) have been shown to
interfere with the expression of fear. This study assessed whether Pr
h lesions would also disrupt the inhibition of fear as measured with c
onditioned inhibition of fear-potentiated startle. Following light + s
hock, noise --> light-no shock conditioned-inhibition training, rats w
ere given Prh lesions. The lesions interfered with the expression of f
ear-potentiated startle to the light. To assess whether conditioned in
hibition was affected, the rats were given light + retraining without
additional noise --> light - training. The noise-conditioned inhibitor
retained its ability to inhibit fear-potentiated startle to the retra
ined light. These results suggest that the areas of the Prh that are e
ssential for the initial expression of conditioned fear are not import
ant for the expression of conditioned inhibition of fear.