Saccharin drinking rather than open field behaviour predicts initial ethanol acceptance in Wistar rats

Area of Science:

• Neuroscience and behavioral science
• Animal models of substance use

Background:

• Individual differences in fluid intake, particularly sweet solutions, may influence susceptibility to ethanol consumption.
• Open field behavior is often used to assess general activity and anxiety-like behaviors in rodents, but its predictive value for substance intake is debated.

Purpose of the Study:

• To investigate the predictive relationship between saccharin drinking and open field behavior on subsequent ethanol consumption in Wistar rats.
• To determine if saccharin intake can serve as a biomarker for initial ethanol acceptance.

Main Methods:

• Wistar rats were assessed for saccharin intake and open field behavior.
• Ethanol acceptance was measured using two-bottle choice (2-8% v/v ethanol vs water) and later three-bottle choice (8% vs 16% ethanol vs water) paradigms.
• Correlational analyses were performed to link fluid intake and behavioral data with ethanol consumption.

Main Results:

• Both absolute saccharin intake and increased fluid intake with saccharin positively correlated with initial acceptance of low ethanol concentrations (2-8%).
• This correlation between saccharin drinking and ethanol intake diminished in subsequent weeks with higher ethanol concentrations (8-16%).
• No correlation was found between open field test parameters (locomotion, rearing, central entries) and subsequent ethanol consumption.

Conclusions:

• Saccharin drinking, not open field behavior, may predict ethanol intake during initial exposure to low ethanol concentrations.
• The predictive value of saccharin intake for ethanol consumption is transient and dependent on ethanol concentration and exposure duration.
• These findings suggest specific palatability preferences might influence early-stage ethanol acceptance in rats.