Oxytocin attenuates nucleus accumbens-connectivity during alcohol cue presentation: Evidence from a recent randomized cross-over study

Introduction The brainʼs oxytocin system is involved in a variety of addictive behaviors. In animal studies, the application of oxytocin led to a permanent decrease in the preference for alcoholic beverages and to a reduction in alcohol consumption. The effects of oxytocin have been linked to the modulation of neurotransmission and functional connectivity in the brainʼs reward system, the striatum and the nucleus accumbens (NAc). First human studies were able to demonstrate an effect of oxytocin on subjective alcohol cravings and neural cue-reactivity. However, the effects of oxytocin on functional connectivity during the presentation of alcohol-related stimuli have not been investigated in human studies.

Methods We investigated the effects of oxytocin on functional brain activation in a randomized cross-over trial in N = 15 participants with high alcohol consumption using functional magnetic resonance imaging (fMRI). 24 IU oxytocin vs. placebo (intranasal) were applied 40 minutes prior to the assessment of functional brain connectivity during the presentation of alcohol and neutral stimuli.

Results The fMRI results show a significant modulation of functional connectivity in the NAc, thalamus, and paracingular gyrus by oxytocin during the presentation of alcohol-related stimuli (all p_FDR < 0.05). This effect was specific to the alcohol condition and was not seen during the presentation of neutral images. The results also indicated a significant correlation between NAc-connectivity and subjective desire for alcohol (r = 0.538, p = 0.024).

Conclusion The results of the current study provide first evidence of a condition-specific and significant attenuation of NAc-connectivity by oxytocin, which was associated with a lower subjective alcohol craving. The oxytocin-induced modulation of NAc-connectivity was specific for the processing of alcohol stimuli and could reflect a reduction in the stimulus salience of alcohol stimuli by oxytocin.