Psychophysiology of Delayed Extinction and Reconsolidation in Humans
Final rept. 20 Jan 2011 - 19 Jan 2015
MASSACHUSETTS GENERAL HOSPITAL BOSTON
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Animal research suggests that reactivation retrieval of a consolidated memory can return it to a labile state from which it must be restabilized in order to persist. This stabilization process has been termed reconsolidation, and various behavioral and pharmacological interventions have been found to modify or block it. The aim of this project was to create an experimental assay in the form of an optimal Pavlovian differential fear-conditioning paradigm, within which the relative strengths of various pharmacological and behavioral, reconsolidation-blocking interventions could be tested. We completed testing for two pharmacological interventions and a behavioral intervention. Study of a third pharmacological intervention was initiated. Results from propranolol and behavioral intervention groups demonstrated differential conditioning learning on Day 1, supporting the validity of our modified fear-conditioning paradigm. Propranolol administration and the behavioral intervention at the time of memory reactivation did not decrease the fear memory, as indexed by skin conductance, when assessing renewal and reinstatement. Mifepristone was tested as a second pharmacological intervention. After adjusting for initial differences in conditioned response strength, results suggest that mifepristone did reduce the fear memory. Results from a third pharmacological intervention, oxytocin, tentatively suggest a generalized reduction of the fear memory.