Pain and reward circuits antagonistically modulate alcohol expectancy to regulate drinking.

Area of Science:

• Neuroscience
• Addiction Research
• Neuroimaging

Background:

• Excessive alcohol consumption is linked to the expectation of physical and social pleasure (PSP).
• This suggests a potential imbalance between reward and pain processing in alcohol-seeking behavior.
• Understanding these competing neural circuits is crucial for addressing problem drinking.

Purpose of the Study:

• To investigate the opposing roles of brain reward and pain circuits in physical and social pleasure (PSP) expectancy.
• To examine how these circuits influence problem drinking severity in humans.
• To elucidate the neural mechanisms underlying the interplay between reward, pain, and alcohol use.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) data from 180 participants at rest and 71 during alcohol cue exposure.
• Analyzed functional connectivity between the medial orbitofrontal cortex (mOFC, reward) and periaqueductal gray (PAG, pain).
• Employed mediation and path models to assess the interaction of mOFC and PAG connectivities on PSP expectancy and drinking severity.

Main Results:

• During rest, mOFC connectivity positively correlated with PSP scores, while PAG connectivity negatively correlated, converging in the precentral gyrus (PrCG).
• Stronger PAG-PrCG relative to mOFC-PrCG connectivity predicted lower PSP expectancy.
• During alcohol cue exposure, net PAG vs. mOFC connectivity with the occipital cortex negatively predicted PSP expectancy.

Conclusions:

• The reward (mOFC) and pain (PAG) circuits exhibit functional antagonism in the context of alcohol use.
• mOFC connectivity enhances the expectation of drinking pleasure, whereas PAG connectivity counteracts this effect.
• These opposing neural influences on expectancy and craving indirectly modulate problem drinking.