Alcohol-seeking associations with resting state functional connectivity of the amygdala

Prolonged alcohol use is associated with neuroadaptations that may contribute to continued alcohol consumption, even in the presence of adverse consequences. Although well studied in preclinical models, the neural mechanisms of aversion-resistant alcohol-seeking in humans are understudied.

The goal of this study was to examine whether altered amygdala resting state functional connectivity (rsFC) is a mechanism for how lifetime drinking history and alcohol use disorder symptoms relate with objectively measured neutral and aversion-resistant alcohol-seeking in the human laboratory.

A sample of 55 adults (age 21-55, mean=32.18 years, 56.4 % female, 60.0 % White) completed two counterbalanced intravenous alcohol progressive-ratio self-administration sessions (pairing alcohol-seeking with aversive or neutral stimuli) and a resting state fMRI scan. Two bilateral a priori amygdala seed regions were selected.

rsFC strength of the left basolateral amygdala and dorsal anterior cingulate cortex mediated the relationships between both lifetime alcohol use and alcohol use disorder symptom severity with alcohol-seeking in the aversive session. rsFC between the right centromedial amygdala and occipital regions was associated with, but not specific to, alcohol-seeking during the neutral session; this connectivity mediated the association with alcohol use disorder symptom severity, but not the association with lifetime alcohol use.

This study provides evidence linking the basolateral amygdala to human aversion-resistant alcohol-seeking. Identification of brain mechanisms underlying aversion-resistant alcohol-seeking can facilitate translational research and identify physiological mechanisms of alcohol use disorder progression.