Wheel running, voluntary ethanol consumption, and hedonic substitution

Area of Science:

• Neuroscience
• Behavioral Science

Background:

• Natural and drug rewards activate similar brain pathways.
• However, behavioral evidence suggests differences in perceived value between natural rewards (e.g., food) and drugs like ethanol.
• Limited research exists on the interplay between natural behaviors and ethanol consumption.

Purpose of the Study:

• To investigate the relationship between natural reinforcing stimuli and ethanol consumption in ethanol-preferring C57BL/6J mice.
• To determine if environmental enrichment and wheel running influence ethanol intake.
• To assess if ethanol access affects wheel running behavior.

Main Methods:

• Utilized a high-resolution volumetric drinking monitor and wheel running monitor in female C57BL/6J mice.
• Manipulated environmental conditions: standard vs. enhanced environment, wheel access vs. no access, and presence vs. absence of ethanol.
• Evaluated effects of alternating wheel running access on ethanol behaviors and vice versa.

Main Results:

• Ethanol consumption remained stable despite alternating periods of wheel running access.
• Wheel running behavior increased significantly when ethanol was unavailable and decreased upon its reintroduction.
• An alcohol deprivation effect was observed when ethanol was reintroduced after a period of absence.

Conclusions:

• Findings support hedonic substitution theories, indicating that natural rewards may substitute for drug rewards.
• Female C57BL/6J mice exhibit ethanol-seeking and craving behaviors under the studied conditions.
• Environmental enrichment and physical activity can modulate, but not eliminate, ethanol consumption patterns.