Alcohol attenuates amygdala–frontal connectivity during processing social signals in heavy social drinkers

Abstract

Rationale Convergent evidence shows that alcohol exerts its effects on social behavior via modulation of amygdala reactivity to affective stimuli. Given that affective processing involves dynamic interactions between the amygdala and the prefrontal cortex (PFC), alcohol's effects are likely to extend beyond regional changes in brain activity to changes that manifest on a broader functional circuit level. Objective The current study examines alcohol's effects on functional connectivity (i.e., ‘coupling’) between the amygdala and the PFC during the processing of socio-emotional stimuli using functional magnetic resonance imaging (fMRI). Methods In a randomized, double blind, placebo-controlled, within-subjects cross-over design, twelve heavy, social drinkers performed an fMRI task designed to probe amygdala response to socio-emotional stimuli (angry, fearful, and happy faces) following acute ingestion of alcohol or placebo. Functional connectivity between the amygdala and PFC was examined and compared between alcohol and placebo sessions using a conventional generalized psychophysiological interaction (gPPI) analysis. Results Relative to placebo, alcohol reduced functional coupling between the amygdala and the right orbitofrontal cortex (OFC) during processing of both angry and fearful faces. Alcohol also reduced functional coupling between the amygdala and left OFC during processing of happy faces. Conclusions These preliminary findings suggest that alcohol's effects on social behavior may be mediated by alternations in functional connectivity between the amygdala and OFC during processing of emotional faces.

Acute Effects of Alcohol on Encoding and Consolidation of Memory for Emotional Stimuli

“…Participants were told that the study was investigating the effects of drugs and pictures on mood, and to minimize drug expectancies they were told they could receive one of the following: stimulant, sedative, alcohol, or placebo (Conrad et al, 2012;Gorka et al, 2013;King et al, 2014). They were instructed to consume their normal amounts of caffeine and nicotine but to abstain from drugs, including alcohol, for 24 hours before each session, and to not consume any food after 9 A.M.…”

Neural and Behavioral Correlates of Alcohol-Induced Aggression Under Provocation

“…Aggressive behavior has also been linked to PFC hypo-activation, especially in the dorsal (d) ACC (Sterzer et al, 2005;Meyer-Lindenberg et al, 2006;Aharoni et al, 2013), and to increased activation of the amygdala, in particular for impulsive aggression triggered by provocation or threat, also referred to as reactive aggression (Meyer-Lindenberg et al, 2006;Coccaro et al, 2007). Reduced functional PFC-amygdala coupling under alcohol (Gorka et al, 2013) further suggests that alcohol-induced aggression might be mediated by impaired PFC functioning under alcohol, which might indirectly increase activation of the amygdala (Heinz et al, 2011).…”

Prefrontal Limbic-Striatal Circuits and Alcohol Addiction in Humans

“…In an fMRI study examining the acute effect of alcohol in 12 heavy but non-dependent social drinkers (greater than or equal to 10 alcoholic drinks per week and one to five weekly binge-drinking episodes), participants displayed reduced amygdalar activity to fearful and angry faces after the ingestion of alcoholic beverages compared with the placebo session (Sripada et al, 2011). Using the same data set, this group additionally found that the functional connectivity of the amygdala was decreased in the right OFC during the viewing of angry and fearful faces and in the left OFC during the viewing of happy faces following the acute ingestion of alcohol (Gorka et al, 2013). This result is consistent with a previous report that an intravenous injection of alcohol decreases limbic brain response to fearful faces in healthy individuals (Gilman et al, 2008).…”

“…Several fMRI studies have reported that alcohol attenuates emotional response to aversive or threat-related stimuli via its influence on limbic regions (Gilman et al, 2008;Gorka, Fitzgerald, King, & Phan, 2013;Sripada et al, 2011). In an fMRI study examining the acute effect of alcohol in 12 heavy but non-dependent social drinkers (greater than or equal to 10 alcoholic drinks per week and one to five weekly binge-drinking episodes), participants displayed reduced amygdalar activity to fearful and angry faces after the ingestion of alcoholic beverages compared with the placebo session (Sripada et al, 2011).…”