Effects of isolation during development on reactivity and home-cage agonistic behavior in rats

Abstract

This experiment was designed to determine whether isolation during two developmental periods would contribute to differences in home‐cage agonistic behavior and whether altered reactivity was a mediating variable. While early isolation (16–41 days) was shown to have a significant and sustained impact on agonistic behavior, isolation during a later developmental period (41–68 days) did not result in altered occurrences of agonistic behavior. While isolation did result in increased reactivity to both footshock and dorsal tactile stimuli, the pattern of these data suggested that hyperreactivity to tactile stimulation was not a satisfactory account of the increased agonistic behavior of rats raised in isolation.

Play fighting versus serious fighting in golden hamsters (Mesocricetus auratus)

“…Five of the studies suggest that early social deprivation reduces aggression toward intruders (Allen & Boyce, 1976;Blanchard & Blanchard, 1980;Flannelly, Flannelly, & Blanchard, 1984;Luciano & Lore, 1975;Price, 1978), although the effect was significant in only two of them. In contrast, Wahlstrand, Knutson, and Viken (1983) found more fighting. And, finally, Takahashi (1986) and Potegal and Einon (1989) did not find any effect on later intraspecific aggression.…”

“…The encounters were videotaped with a VHS Bosch video camera for subsequent detailed quantitative data analysis . The occurrence of fighting can vary as a function of time elapsed since the onset of an observation session (Wahlstrand et al, 1983), so treatment conditions were equated for the number of observations conducted within each of the successive lO-min experimental periods.…”

Important Hints in Behavioural Teratology of Rodents

“…individually housed) for some weeks. The effects of the isolation are markedly age-dependent in mice [227] and rats [228]. In the latter, isolation during a later developmental stage (day 41-68) does not result in consistent alteration in aggressive behaviour.…”

Appropriate end points for the characterization of behavioral changes in developmental toxicology.

“…Very recently, Terranova et al (75) characterized a complete mouse ethogram aimed at evaluating both normal maturation profiles and long-lasting effects upon developmental drug exposure (76). The effects of social isolation are highly age dependent in both species (77)(78)(79). The onset of sexual behavior depends on various factors, including social cues (80)(81)(82).…”