INHIBITORY AVOIDANCE-LEARNING ALTERS THE AMYGDALA CALCIUM CALMODULIN-DEPENDENT PROTEIN-KINASE-II ACTIVITY IN RATS/

This study investigated the role of amygdala CaM-kinase II (calcium/ca lmodulin-dependent protein kinase II) in affective learning and memory . In Experiment I, two groups of rats were trained on a one-trial step through inhibitory avoidance learning task. The experimental group re ceived a high intensity foot shock contingent upon the stepping-throug h behavior, whereas the control group received a series of non-conting ent low intensity foot shock during training. The experimental rats sh owed significantly higher retention scores than the control rats. Corr espondingly, rats in the experimental group showed significantly highe r Ca2+-independent activity of a CaM-kinase II than the controls. Intr a-amygdala injection of a specific CaM-kinase II inhibitor, KN-62, bef ore the training trial disrupted affective learning. In comparison wit h the vehicle-injected controls, pretraining injection of KN-62 impair ed the acquisition of affective specific learning. These results, take n together, indicated that the activation of amygdala CaM-kinase LI in the amygdala is associated with the affective learning behavior, and may be one of the neural mechanisms underlying formation of affective memory.