Fear conditioning in mouse lines genetically selected for binge-like ethanol drinking

Area of Science:

• Neuroscience
• Addiction Research
• Psychiatry

Background:

• Comorbidity of substance use disorders (AUD) and psychiatric conditions like PTSD is common.
• Binge drinking is a critical factor in addiction development, often used for self-medication by PTSD patients.
• High Drinking in the Dark (HDID) mice were developed for high blood ethanol concentrations (BECs) to model binge-like drinking.

Purpose of the Study:

• To assess if HDID mice, bred for binge-like alcohol consumption, exhibit altered conditioned fear learning.
• To determine the suitability of HDID mice for studying the interplay between PTSD-like behaviors and alcohol binge drinking.

Main Methods:

• Two mouse lines (HDID-1, HDID-2) and control HS/Npt mice were used.
• A standard conditioned fear protocol involving context and cue conditioning, extinction, and renewal was employed.
• Fear responses (freezing behavior) were measured in response to context and cues.

Main Results:

• All mouse genotypes acquired, generalized, and extinguished conditioned fear responses similarly.
• Context paired with shock elicited freezing, while unpaired cues did not, confirming typical fear learning.
• Fear learning was not influenced by genes predisposing to binge drinking.

Conclusions:

• Genes influencing binge drinking predisposition do not appear to affect fear learning mechanisms.
• HDID mice are a valid model for investigating the specific role of conditioned fear in binge-like alcohol consumption.
• This research provides a foundation for studying the neural mechanisms underlying the comorbidity of PTSD and alcohol use disorder.