Inelastic demand for alcohol in rats

Area of Science:

• Behavioral neuroscience
• Animal models of addiction
• Neurobiology of substance use

Background:

• Investigating alcohol preference determinants requires concurrent access to alcohol and isocaloric food.
• Traditional animal models show sucrose reduces alcohol intake.
• Sweetened alcohol intake is defended by rats even with competing food options.

Purpose of the Study:

• To determine if rats defend alcohol consumption levels when competing with an isocaloric preferred food.
• To assess if rats decrease food intake and increase effort to maintain alcohol consumption.

Main Methods:

• Rats chose between a 10% alcohol/0.25% saccharin solution and an isocaloric 14.8% Polycose solution.
• Response requirements (variable-ratio) for each solution increased progressively (5 to 30 responses).

Main Results:

• Initially, rats consumed more Polycose than alcohol.
• As response requirements increased, Polycose consumption decreased.
• Sweetened alcohol consumption remained stable or increased, except at the highest response requirement (variable-ratio 30).

Conclusions:

• Rats defended their intake of sweetened alcohol but not the preferred food.
• Alcohol and food consumption can be independently regulated.
• Rodent models of alcohol-regulated preference may inform human alcohol consumption mechanisms.