Effects of noradrenergic system on contextual memory specificity
Memories for emotionally arousing experiences are more remembered when compared to memories for emotionally neutral events. Epinephrine released as a response to sympathetic nervous system activation during stressful events plays an important role in modulating the consolidation of episodic memories. The increased in peripheral levels of epinephrine induce an enhancement in norepinephrine (NE) levels in forebrain structures. Several evidences suggest that the activation of β-adrenergic receptors in these structures is one of the main mechanisms for modulation of memory consolidation. Although several studies have investigated the effects of noradrenergic system in memory consolidation, little is known about its effects in contextual memory specificity. The present research project aims to investigate how the noradrenergic system activation and blockade, through systemic administration of yohimbine (α2 receptor antagonist) and propranolol (β-adrenergic antagonist), respectively, modulates both the strength and accuracy of contextual memories. The results of the present project will be relevant for the understanding of psychiatric disorders such as posttraumatic stress disorder, which presents symptoms as generalized fear responses, in which it has been suggested an involvement of the noradrenergic system and, more specifically, of β-adrenergic receptors.