Caloric restriction in grouped rats: aggregate influence on behavioural and hormonal data

Area of Science:

• Gerontology
• Animal Behavior
• Endocrinology

Background:

• Caloric restriction (CR) studies often use single-housed animals, posing logistical challenges.
• Understanding CR effects in group-housed settings is crucial for translational research.
• Previous research highlights CR's impact on aging, oxidative stress, and cognition, but group-housing effects are less explored.

Purpose of the Study:

• To assess weight and social behavior differences in ad libitum versus CR (70%) fed rats.
• To investigate weight and social behavior variations in sibling versus non-sibling rats under CR.
• To compare serum corticosterone levels as a stress biomarker between ad libitum and CR conditions.

Main Methods:

• Group-housed rats were subjected to either ad libitum feeding or 70% caloric restriction.
• Weight proportions and social behaviors (feeder time, 'pushes') were recorded.
• Serum corticosterone concentrations were measured to assess stress levels.

Main Results:

• Caloric restriction was effective across all tested groups, irrespective of sibling status.
• No significant adverse weight changes were observed in CR rats.
• Sibling rats displayed increased time at the feeder and more 'pushes' compared to non-siblings, but corticosterone levels remained comparable across groups.

Conclusions:

• Group-housing rats during long-term caloric restriction is a viable experimental model.
• Caloric restriction effectively modulates physiological parameters without inducing extreme weight loss or elevated stress in group-housed rats.
• Sibling relationships may influence specific social behaviors under CR, but do not impact stress hormone levels.