How Administration of the Beta-Blocker Propranolol Before Extinction can Prevent
the Return of Fear
#MMPMID26462618
Kroes MC
; Tona KD
; den Ouden HE
; Vogel S
; van Wingen GA
; Fernández G
Neuropsychopharmacology
2016[May]; 41
(6
): 1569-78
PMID26462618
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Combining beta-blockers with exposure therapy has been advocated to reduce fear,
yet experimental studies combining beta-blockers with memory reactivation have
had contradictory results. We explored how beta-blockade might affect the course
of safety learning and the subsequent return of fear in a double-blind
placebo-controlled functional magnetic resonance imaging study in humans (N=46).
A single dose of propranolol before extinction learning caused a loss of
conditioned fear responses, and prevented the subsequent return of fear and
decreased explicit memory for the fearful events in the absence of drug.
Fear-related neural responses were persistently attenuated in the dorsal medial
prefrontal cortex (dmPFC), increased in the hippocampus 24?h later, and
correlated with individual behavioral indices of fear. Prediction error-related
responses in the ventral striatum persisted during beta-blockade. We suggest that
this pattern of results is most consistent with a model where beta-blockade can
prevent the return of fear by (i) reducing retrieval of fear memory, via the
dmPFC and (ii) increasing contextual safety learning, via the hippocampus. Our
findings suggest that retrieval of fear memory and contextual safety learning
form potential mnemonic target mechanisms to optimize exposure-based therapy with
beta-blockers.
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