LeDoux Lab 2009 SfN Abstracts
 
Program#/Poster#: 479.19/FF120
Title: Stimulation of amygdala beta-adrenergic receptors enhances acquisition of fear conditioning
Location: South Hall A
Presentation Time: Monday, Oct 19, 2009, 3:00 PM - 4:00 PM
Authors: *E. M. CAPAROSA, D. E. A. BUSH, J. E. LEDOUX;
Ctr. for Neural Sci., New York Univ., New York, NY
Abstract: Recent work has demonstrated that blockade of beta-noradrenergic receptors in the lateral amygdala (LA), a region of the brain critical for fear learning, disrupts fear memory acquisition and reconsolidation. The present experiment evaluated whether or not direct stimulation of LA beta-adrenergic receptors with isoproterenol, a beta-adrenergic agonist, can enhance the strength of fear conditioning under conditions that normally support only weak fear learning. In Pavlovian auditory fear conditioning an aversive unconditioned stimulus (US; e.g. footshock) is paired with an initially neutral auditory conditioned stimulus (CS; e.g. a tone), which endows the CS with the capacity to elicit conditioned fear responses. To test the effects of LA beta-adrenergic stimulation on fear conditioning, rats were exposed to a mild fear conditioning protocol, and given pre-conditioning infusions of isoproterenol or vehicle. Results showed that pre-conditioning intra-LA isoproterenol enhanced fear memory acquisition. The results support the hypothesis that fear memory formation is enhanced under conditions of high levels of beta-adrenergic receptor stimulation in the amygdala. Evaluation of the ways in which noradrenergic function can modulate the strength of fear learning provides insight to the potential role of noradrenaline in anxiety disorders, with specific relevance to post-traumatic stress disorder.
Support: R37 MH038774
P50 MH058911
R01 MH046516