| LeDoux Lab 2010 SfN Abstracts |
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| Program#/Poster#: | 914.25/MMM41 |
| Title: | The effects of corticotropin releasing factor infused into lateral amygdala on reconsolidation and extinction of fear conditioning |
| Location: | Halls B-H |
| Presentation Time: | Wednesday, Nov 17, 2010, 1:00 PM - 2:00 PM |
| Authors: | *K. ISOGAWA1,
D. E. A. BUSH1, Z. A. EVANS1, J. E. LEDOUX1,2; 1New York Univ., NEW YORK, NY; 2Emotional Brain Inst. at the Nathan S. Kline Inst. for Psychiatry Res., Orangburg, NY |
| Abstract: | The amygdala is known to be a primary component of the neural circuitry underlying Pavlovian fear conditioning, an emotional learning paradigm that involves forming an association between an initially neutral conditioned stimulus (CS; e.g. a tone) and an innately aversive unconditioned stimulus (US; usually footshock). The lateral nucleus of the amygdala (LA) is an initial site of convergence for CS and US information in the brain. Corticotropin-releasing-factor (CRF) is a neuropeptide implicated in the control of both behavioral and endocrine responses to stress, and the LA contains high levels of CRF-1 receptors. However, the role of LA CRF receptors in fear conditioning is not well understood. We have previously examined the effects of CRF infusions into the LA on both formation and expression of fear conditioning. Rats given pre-training CRF showed dose-dependent suppression of freezing. Rats given immediate post-training CRF also showed suppression of freezing. Rats given pre-testing CRF showed facilitation of freezing. Here we assessed the effect of CRF infusions into the LA on reconsolidation and extinction of fear conditioning. Rats given pre-reconsolidation phase CRF (30 ng / 0.25 µl / side) showed facilitation of freezing. Rats given extinction phase CRF (30 ng / 0.25 µl / side) showed delayed extinction of freezing. These findings may have important implications for understanding the mechanisms underlying contributions of CRF to fear-related disorders. In major depressive disorder (MDD) patients and posttraumatic stress disorder (PTSD) patients, CRF in cerebrospinal fluid is higher than control subjects. These patients readily retrieve and reconsolidate past aversive emotional memories but form with difficulty new aversive emotional memories and extinguish with difficulty past aversive emotional memories. CRF effect in LA may contribute to symptoms of MDD and PTSD. |
| Support: | R37 MH 038774 P50 MH 058911 R01 MH 046516 |