Rats do not consider all unfamiliar strains to be equivalent

Area of Science:

• Animal behavior
• Social cognition
• Neuroscience

Background:

• Social similarity influences human behavior, but its role in non-human animals is less understood.
• Wistar rats exhibit stress mitigation in the presence of familiar Wistar rats, indicating social similarity's importance.
• Previous findings suggest Wistar rats' stress responses are buffered by unfamiliar Sprague-Dawley (SD) and Long-Evans (LE) rats, but not Fischer 344 (F344) rats.

Purpose of the Study:

• To investigate if Wistar rats can categorize unfamiliar rats based on strain.
• To determine if Wistar rats exhibit social preferences among different rat strains.
• To explore the role of social similarity in Wistar rat stress responses and social interactions.

Main Methods:

• Behavioral experiments presenting Wistar subject rats with unfamiliar rats of different strains (Wistar, SD, LE, F344).
• Observation and quantification of subject rats' social proximity and interaction preferences.
• Stress response assessment in Wistar rats exposed to different unfamiliar rat strains.

Main Results:

• Wistar rats demonstrated the ability to categorize unfamiliar rats by strain.
• Wistar subjects showed a preference for unfamiliar Wistar, SD, and LE rats over F344 rats.
• No significant preference was observed among Wistar, SD, and LE rats, and no aversion to F344 rats was detected.

Conclusions:

• Wistar rats recognize social similarity to specific unfamiliar rat strains (Wistar, SD, LE).
• Strain categorization influences social preferences and potentially stress-buffering mechanisms in rats.
• These findings highlight the capacity for social categorization and preference based on social similarity in rodents.