Brain regional gene expression network analysis identifies unique interactions between chronic ethanol exposure and...

Area of Science:

• Neuroscience
• Genetics
• Pharmacology

Background:

• Progressive increases in ethanol consumption characterize alcohol use disorder (AUD).
• Altered neural signaling, driven by persistent changes in brain gene expression, is hypothesized to cause excessive alcohol consumption in AUD.

Purpose of the Study:

• To identify brain regional gene expression networks associated with progressive ethanol consumption in a mouse model of AUD.
• To investigate the interaction between chronic intermittent ethanol (CIE) exposure and oral ethanol consumption on gene expression patterns.

Main Methods:

• Utilized a C57BL/6J mouse model with chronic intermittent ethanol (CIE) vapor exposure and limited oral ethanol access.
• Performed microarray and scale-free network analysis on gene expression in the medial prefrontal cortex, nucleus accumbens, hippocampus, bed nucleus of the stria terminalis, and central nucleus of the amygdala.
• Conducted bioinformatics studies to analyze ethanol-responsive gene expression, correlation with ethanol consumption, and functional content.

Main Results:

• The most significant gene expression changes occurred in mice exposed to CIE and drinking compared to ethanol-naïve mice.
• The prefrontal cortex exhibited unique gene expression patterns compared to other brain regions.
• Network analysis revealed modules of co-expressed genes in all studied brain regions, with the prefrontal cortex and nucleus accumbens showing the most significant correlation with drinking behavior.
• Modules strongly correlated with drinking behavior were functionally enriched for synaptic transmission and plasticity across brain regions.

Conclusions:

• Gene expression networks in specific brain regions, especially the prefrontal cortex and nucleus accumbens, are significantly altered by chronic intermittent ethanol exposure and drinking.
• These alterations in gene expression are linked to synaptic function and plasticity, potentially underlying the progressive increase in ethanol consumption observed in alcohol use disorder.