Format

Send to

Choose Destination
Psychopharmacology (Berl). 2005 Aug;180(4):670-9. Epub 2005 Sep 14.

Individual differences in threat sensitivity predict serotonergic modulation of amygdala response to fearful faces.

Author information

1
MRC Behavioural and Clinical Neuroscience Centre. roshanco@berkeley.edu

Abstract

RATIONALE:

In this study we used functional magnetic resonance imaging (fMRI) to examine the effects of acute tryptophan depletion (ATD), a well-recognised method for inducing transient cerebral serotonin depletion, on brain activation to fearful faces.

OBJECTIVES:

We predicted that ATD would increase the responsiveness of the amygdala to fearful faces as a function of individual variation in threat sensitivity.

METHODS:

Twelve healthy male volunteers received a tryptophan depleting drink or a tryptophan balancing amino acid drink (placebo) in a double-blind crossover design. Five hours after drink ingestion participants were scanned whilst viewing fearful, happy and neutral faces.

RESULTS:

Consistent with previous findings, fearful faces induced significant signal change in the bilateral amygdala/hippocampus as well as the fusiform face area and the right dorsolateral prefrontal cortex. Furthermore, ATD modulated amygdala/hippocampus activation in response to fearful relative to happy faces as a function of self-reported threat sensitivity (as measured with the Behavioral Inhibition Scale; Carver CS, White TL (1994) Behavioral inhibition, behavioral activation, and affective responses to impending reward and punishment: the BIS/BAS scales. J Pers Soc Psychol 67:319-333).

CONCLUSION:

The data support the hypothesis that individual variation in threat sensitivity interacts with manipulation of 5-HT function to bias the processing of amygdala-dependent threat-relevant stimuli.

PMID:
15772862
DOI:
10.1007/s00213-005-2215-5
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center