Individual differences in ethanol drinking meal structure are shaped by social environments.

Area of Science:

• Neuroscience
• Behavioral Science
• Pharmacology

Background:

• Alcohol use disorder (AUD) exhibits significant heterogeneity in drinking patterns and health outcomes.
• Preclinical models are crucial for understanding interindividual variability in AUD.
• Existing methods may not fully capture the nuances of drinking behavior.

Purpose of the Study:

• To analyze high-resolution mouse ethanol intake data using capacitive lickometers (LIQ PARTI and LIQ HD).
• To quantify behavioral variability in ethanol consumption across different housing conditions (group vs. single) and sexes.
• To identify distinct drinking phenotypes and their relationship with social behaviors.

Main Methods:

• Utilized open-source capacitive lickometer systems for continuous, high-resolution monitoring of mouse fluid intake.
• Developed a fluid "meal" pattern analysis integrating ethanol and water consumption to define discrete drinking episodes.
• Applied principal component analysis (PCA) to meal variables and conducted a tube test dominance assay to assess social hierarchy.

Main Results:

• Substantial individual differences in alcohol intake were observed, varying by sex and housing status.
• Fluid meal pattern analysis revealed sex- and housing-dependent drinking structures, with group-housed males showing fewer but faster meals.
• PCA identified a "distributed meal" phenotype (increased meal number, reduced size, earlier onset, higher ethanol preference) associated with male offensive dominance behavior.

Conclusions:

• High-resolution, longitudinal analysis of ethanol drinking reveals distinct behavioral phenotypes.
• These phenotypes are linked to key components of social behaviors, particularly in males.
• This approach provides a framework for understanding heterogeneity in AUD-related drinking patterns.