Alcohol Dependence Modifies Brain Networks Activated During Withdrawal and Reaccess: A c-Fos-Based Analysis in Mice

Area of Science:

• Neuroscience
• Addiction Research
• Systems Neuroscience

Background:

• High-level alcohol consumption induces neuroplasticity, contributing to pathological drinking.
• Existing research has identified specific brain circuits and cell types affected, but broader adaptation patterns remain unexplored.

Purpose of the Study:

• To investigate whole-brain neuronal activity patterns during alcohol withdrawal and reaccess.
• To identify network changes associated with high-drinking behavior in a mouse model of alcohol dependence.

Main Methods:

• Utilized whole-brain c-Fos mapping and network analysis in mice undergoing chronic intermittent ethanol exposure.
• Assessed neuronal activity 24 hours post-withdrawal and immediately after alcohol reaccess.
• Employed graph theory to analyze network properties and classified mice as high or low drinkers.

Main Results:

• Widespread increased neuronal activity (c-Fos expression) was observed during withdrawal, which was reversed by alcohol reaccess.
• High-drinking mice showed increased network modularity after reaccess compared to withdrawal.
• The cortical amygdala exhibited increased coactivation during withdrawal in high-drinking mice, and its silencing reduced drinking behavior.

Conclusions:

• Alcohol withdrawal alters brain network organization in dependent mice, with reaccess drinking attenuating these changes.
• Olfactory brain regions, particularly the cortical amygdala, are implicated in driving these alcohol-induced adaptations.
• The cortical amygdala may play a significant, underappreciated role in the neurobiology of alcohol dependence.