Summary: Alcohol consumption affects amygdala oscillations differently in male and female mice, especially after repeated exposure.
Alcohol alters synchronized brain activity in the amygdala of mice, but differently for male and female mice, according to new research published in eNeuro.
Alcohol misuse often goes hand-in-hand with anxiety and depression, and a brain region called the amygdala is involved in both.
Changes in synchronized brain activity, called oscillations, between areas like the amygdala and prefrontal cortex can influence anxious and fearful behaviors in both rodents and humans. Yet how alcohol may impact the amygdala network to change behavior is not known.
DiLeo et al. administered alcohol to mice and measured corresponding changes in oscillatory states in the amygdala.
Alcohol affected amygdala oscillations differently in male and female mice, especially after repeated alcohol administration. In fact, the oscillatory state of females did not change at all after repeated alcohol administration.
The researchers repeated the experiment in mice without a subunit of a receptor linked to alcohol use and anxiety, which induced traits of the female network activity in males.
These results indicate alcohol can trigger the amygdala to switch activity states, which may drive changes in anxious and fearful behavior.
About this alcohol and neuroscience research news
Author: Press Office Source: SfN Contact: Press Office – SfN Image: The image is credited to DiLeo et al., eNeuro 2022
Sex differences in the alcohol-mediated modulation of BLA network states
Alcohol use, reported by 85% of adults in the United States, is highly comorbid with mood disorders, like generalized anxiety disorder and major depression.
The basolateral amygdala (BLA) is an area of the brain that is heavily implicated in both mood disorders and alcohol use disorder. Importantly, modulation of BLA network/oscillatory states via parvalbumin-positive (PV) GABAergic interneurons has been shown to control the behavioral expression of fear and anxiety.
Further, PV interneurons express a high density of δ-subunit-containing GABAA receptors (GABAARs), which are sensitive to low concentrations of alcohol. Therefore, we hypothesized that the effects of alcohol may modulate BLA network states that have been associated with fear and anxiety behaviors via δ-GABAARs on PV interneurons in the BLA.
Given the impact of ovarian hormones on the expression of δ-GABAARs, we also examined the ability of alcohol to modulate local field potentials (LFPs) in the BLA from male and female C57BL/6J and Gabrd-/- mice after acute and repeated exposure to alcohol.
Here, we demonstrate that acute and repeated alcohol can differentially modulate oscillatory states in male and female C57BL/6J mice, a process which involves δ-GABAARs.
This is the first study to demonstrate that alcohol is capable of altering network states implicated in both anxiety and alcohol use disorders.