The reinforcement omission effect on behavioral repertoire of rats with lesions in the basolateral complex and central nucleus of the amygdala

Reinforcement omission has been used as a procedure for the evaluation of attentional and motivational processes. Studies show that the activation of some amygdala nuclei may be involved in the modulation of these processes. This study examined the reinforcement omission effects on behavioral repertoire of rats with lesions in the central nucleus and basolateral complex of the amygdala, using classical conditioning and non-contingent reinforcement schemes. Each trial constituted of a 20 second tone, always followed by the delivery of water, in the 19th second. In the sessions involving omission, the water was delivered in half of the trials. The results showed that all groups responded to the omission and only the Basolateral group showed effect in the “Rearing” category, in the period after the omission. These results highlight the need to consider the involvement of a more complex neural network for evaluation of these effects.