Abstract

BACKGROUND
Oxytocin, classically involved in social and reproductive activities, is increasingly recognized as an antinociceptive and anxiolytic agent, effects which may be mediated via oxytocin's interactions with the dopamine system. Thus, genetic variation within the oxytocin gene (OXT) is likely to explain variability in dopamine-related stress responses. As such, we examined how OXT variation is associated with stress-induced dopaminergic neurotransmission in a healthy human sample.
METHODS
Fifty-five young healthy volunteers were scanned using [¹¹C]raclopride positron emission tomography while they underwent a standardized physical and emotional stressor that consisted of moderate levels of experimental sustained deep muscle pain, and a baseline, control state. Four haplotype tagging single nucleotide polymorphisms located in regions near OXT were genotyped. Measures of pain, affect, anxiety, well-being and interpersonal attachment were also assessed.
RESULTS
Female rs4813625 C allele carriers demonstrated greater stress-induced dopamine release, measured as reductions in receptor availability from baseline to the pain-stress condition relative to female GG homozygotes. No significant differences were detected among males. We also observed that female rs4813625 C allele carriers exhibited higher attachment anxiety, higher trait anxiety and lower emotional well-being scores. In addition, greater stress-induced dopamine release was associated with lower emotional well-being scores in female rs4813625 C allele carriers.
CONCLUSIONS
Our results suggest that variability within the oxytocin gene appear to explain interindividual differences in dopaminergic responses to stress, which are shown to be associated with anxiety traits, including those linked to attachment style, as well as emotional well-being in women.

Links

Publisher Full Text

Authors

Love TM, Enoch MA, Hodgkinson CA, Peciña M, Mickey B, Koeppe RA, Stohler CS, Goldman D, Zubieta JK

Institution

Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan 48109-0720, USA. tiflove@umich.edu

Source

Biological psychiatry 72:3 2012 Aug 1 pg 198-206

MeSH

Adult
Alleles
Anxiety
Dopamine
Emotions
Female
Genotype
Humans
Image Processing, Computer-Assisted
Linkage Disequilibrium
Magnetic Resonance Imaging
Male
Object Attachment
Oxytocin
Pain
Polymorphism, Genetic
Polymorphism, Single Nucleotide
Positron-Emission Tomography
Receptors, Dopamine D2
Receptors, Dopamine D3
Sex Characteristics
Stress, Psychological
Synaptic Transmission

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, N.I.H., Intramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22418012