Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Pharmacol Biochem Behav. 2009 Sep;93(3):291-9. doi: 10.1016/j.pbb.2009.02.008. Epub 2009 Feb 28.

Now or Later? An fMRI study of the effects of endogenous opioid blockade on a decision-making network.

Author information

  • 1Department of Psychology, Biomedical Research Imaging Center, University of North Carolina, Chapel Hill 27599-3270, United States. cab@unc.edu

Abstract

Previously, we found that distinct brain areas predict individual selection bias in decisions between small immediate ("Now") and larger delayed rewards ("Later"). Furthermore, such selection bias can be manipulated by endogenous opioid blockade. To test whether blocking endogenous opioids with naltrexone (NTX) alters brain activity during decision-making in areas predicting individual bias, we compared fMRI BOLD signal correlated with Now versus Later decision-making after acute administration of NTX (50 mg) or placebo. We tested abstinent alcoholics and control subjects in a double-blind two-session design. We defined regions of interest (ROIs) centered on activation peaks predicting Now versus Later selection bias. NTX administration significantly increased BOLD signal during decision-making in the right lateral orbital gyrus ROI, an area where enhanced activity during decision-making predicts Later bias. Exploratory analyses identified additional loci where BOLD signal during decision-making was enhanced (left orbitofrontal cortex, left inferior temporal gyrus, and cerebellum) or reduced (right superior temporal pole) by NTX. Additional analyses identified sites, including the right lateral orbital gyrus, in which NTX effects on BOLD signal predicted NTX effects on selection bias. These data agree with opioid receptor expression in human frontal and temporal cortices, and suggest possible mechanisms of NTX's therapeutic effects.

PMID:
19258022
[PubMed - indexed for MEDLINE]
PMCID:
PMC2729462
Free PMC Article

Images from this publication.See all images (5)Free text

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk