The effects of noradrenergic blockade on extinction in humans.
Author(s): Bos MG, Beckers T, Kindt M.
Affiliation(s): Department of Clinical Psychology, University of Amsterdam, The Netherlands.
Publication date & source: 2012, Biol Psychol. , 89(3):598-605
The process of reconsolidation has attracted much attention because of its
potential application for the treatment of psychiatric disorders. Here, we
investigate a possible boundary condition of disrupting reconsolidation with the
noradrenergic antagonist propranolol in humans. Reconsolidation can be initiated
by retrieval of an acquired fear memory, which is in procedure equivalent to
extinction training. If memory retrieval promotes the formation of a novel
extinction memory trace, propranolol may interfere with extinction rather than
with reconsolidation. Using a differential fear conditioning paradigm, we
demonstrate that administration of propranolol (double-blind placebo controlled)
prior to repetitive unreinforced CS presentations did not affect extinction at a
physiological level (startle reflex and skin conductance). At a cognitive level,
propranolol directly impaired extinction learning. These findings indicate that
careful selection of timing parameters is essential to ensure that
pharmacological agents interfere with the intended memory process to reduce fear.