Opioid receptors in the nucleus accumbens regulate attentional learning in the blocking paradigm.

ABSTRACT: Fear learning depends on prediction error, or the discrepancy between the actual and expected outcome of a conditioning trial. These experiments used blocking and unblocking designs to study the role of opioid receptors in the nucleus accumbens (Acb) in predictive fear learning. Previous fear conditioning to a context blocked later fear conditioning to a conditioned stimulus (CS) in that context. Fear learning proceeded normally (i.e., unblocking occurred) if the CS signaled a more intense footshock than was used during previous context conditioning. Blocking and unblocking were mediated by Acb opioid receptors. Acb microinjections of a nonselective opioid receptor agonist prevented blocking, whereas a nonselective antagonist prevented unblocking. Examination of the associative mechanism f

SUBMITTER: Iordanova MD 

PROVIDER: S-EPMC6673876 | biostudies-literature | 2006 Apr

REPOSITORIES: biostudies-literature