Isolation distress in two-week-old rats: influence of home cage, social companions, and prior experience with littermates.
Behavioral and autonomic manifestations of acute isolation distress were studied in 2-week-old rats under novel and home-cage conditions. Levels of ultrasonic vocalization, heart rate, self-grooming, and rises were higher in novel surroundings, while locomotion and digging were more frequent in home cages. Next, we found that a group of 8 unanesthetized agemate pups was just as effective as an anesthetized dam in reducing (by 80-90%) all behaviors of isolated pups in novel surroundings. Finally, singletons reared without littermates during postnatal days 7-14 showed normal isolation responses, and these were as effectively alleviated by littermates as those of normally reared pups. Thus, isolation distress in rats this age is a complex response, modulated over time by aspects of the pups' environment and virtually prevented by the presence of cues common to both mother and littermates.
D000818:Animals; D001522:Behavior, Animal; D004777:Environment; D006339:Heart Rate; D009035:Mothers; D051381:Rats; D011919:Rats, Inbred Strains; D012801:Sibling Relations; D012934:Social Isolation; D014828:Vocalization, Animal