A longitudinal analysis of maternal aggression in Rockland‐Swiss albino mice

Abstract

Female Rockland-Swiss albino mice were treated for aggression during 6 successive pregnancies and lactation periods or until they ceased to re-mate. Fighting behavior was limited only to the lactation phase of each reproductive cycle. Although most animals exhibited fighting during every lactation period they completed, some exhibited fighting in some lactation periods but not in others. The intensity of aggression, as measured by the time spent fighting, was highest during the beginning of each lactation period and declined by the end of each period. Moreover, the intensity of aggression increased across the first 3 lactation periods and then declined on later lactation periods to a point below initial levels. Finally, the fighting behavior exhibited by multiparous animals was not due simply to previous fighting experience in that some multiparous mice exhibited postpartum aggression on the 6th lactation period in the absence of fighting experience during earlier lactation periods.

GABA enhancement of maternal defense in mice: Possible neural correlates

“…Mice-Females with one previous maternal experience were used. Dams with second litters show aggression that is either consistent or elevated from the levels during the first litter (Svare and Gandelman, 1976).…”

Differential Effects of Short- and Long-Term Early Maternal Separation on Subsequent Maternal Behavior in Rats

“…Rats with prior pregnancy and parturition experience also displayed decreased latency to respond to pups when tested 25 days after last pup exposure (Bridges, 1975), and maternal experience, either via pup exposure or parity, allowed for retention of maternal behaviors up to 80 days after initial pup experience (Scanlan, Byrnes, & Bridges, 2006). In mice, parity appears to influence postpartum aggression, with aggression increasing across the first three lactation periods and then declining (Svare & Gandelman, 1976). These variations in levels of maternal aggression may be due, in part, to changes in postpartum hormones (Svare & Gandelman, 1976), and it is has been suggested that parity may alter neural and/or endocrinological responsiveness to pup-related cues (Kinsley, Mann, & Bridges, 1989;Scanlan et al, 2006).…”

Reproductive Experience may Positively Adjust the Trajectory of Senescence

“…Svare and Gandelman (1976) reported that, in Rockland-Swiss albino mice, postpartum aggression continued to increase in intensity, through parity experiences five or six. The animals displayed more aggression with more pregnancies and lactations, as if the combination of pregnancy, hormone exposure, and pup sensory stimulation built a foundation upon which substrate, subsequent pregnancies acted, like stories in a high-rise building.…”