Preadaptation to the feeding schedule does not eliminate activity-based anorexia in rats

Area of Science:

• Behavioral Neuroscience
• Animal Models
• Physiology

Background:

• Activity-based anorexia (ABA) is a complex condition observed in animal models.
• The role of adaptation to feeding schedules in the development of ABA is not fully understood.

Purpose of the Study:

• To investigate if activity-based anorexia (ABA) develops in rats pre-adapted to a restricted feeding schedule.
• To examine the impact of wheel running on feeding behavior and body weight following feeding schedule adaptation.

Main Methods:

• Twenty rats were adapted to a daily 90-minute meal schedule until stable body weight.
• Rats were then divided into two groups: a wheel group (running wheels except during meals) and a cage group (no running wheels).
• Food intake and body weight were monitored during the ABA training phase.

Main Results:

• Wheel running significantly suppressed feeding behavior compared to the cage group.
• Rats in the wheel group exhibited weight loss, while the cage group maintained stable body weight.
• Wheel running activity levels increased over the experimental days.

Conclusions:

• Activity-based anorexia (ABA) can manifest even after rats are fully adapted to a restricted feeding schedule.
• Suppression of feeding due to wheel running appears to be a critical factor in triggering the ABA cycle.
• These findings challenge the hypothesis that interference with adaptation to feeding schedules is the primary cause of ABA.