Early experience affects the traits of monogamy in a sexually dimorphic manner

Abstract

The goal of this study was to examine the effects of early life experiences on the subsequent expression of traits characteristic of social monogamy in prairie voles (Microtus ochrogaster). During cage changes parents and their offspring were either transferred between cages in a cup (zero manipulation, MAN0) or with a gloved hand (one manipulation, MAN1). Following weaning the offspring were tested for alloparental behavior. In adulthood they were tested for the capacity to form partner preferences, behavior in an elevated plus-maze (EPM), and corticosterone levels. MAN0 males (but not females) showed lower levels of alloparental behavior than MAN1 males. MAN0 females (but not males) were less likely to form pair bonds than MAN1 females. MAN0 animals of both sexes were less exploratory in the EPM than MAN1 counterparts. These experiments support the hypothesis that behaviors used to characterize monogamy are vulnerable in a sex-specific manner to early experience.

Paternal Care in Biparental Rodents: Intra- and Inter-individual Variation

“…Bales et al (2007) found that males who, along with their families, were manually removed from their cage during routine cage-changing in the first two postnatal days were more likely to perform alloparental behavior, and engaged in higher levels of alloparenting, when tested with an unrelated pup during the juvenile period, compared to males that, with their families, were removed from the cage in a plastic cup rather than by hand. Notably, pups were not touched directly in either handling paradigm: pups in the "manual" condition dangled from their mothers' nipples while the mother was lifted and moved to a new cage, and those in the "cup" condition were scooped into the cup before being transferred to a new cage.…”

“…In contrast, early handling did not significantly alter AVP expression or AVP binding to V1a receptors in any of the five brain regions studied. Importantly, both mothers and fathers increased their pup-directed behaviors immediately after the handling manipulation on postnatal Day 1, suggesting that effects of handling on pups' behavioral and neuroendocrine development might have been mediated by effects on the parental care that they received (Bales et al 2007(Bales et al , 2011.…”

Oxytocin has dose-dependent developmental effects on pair-bonding and alloparental care in female prairie voles

“…In voles, behavior in the EPM is responsive to changes in state. For instance, mating experience , treatment with AVP (Dharmadhikari et al, 1997) and neonatal handling (Bales et al, 2007a) are associated with increased time spent in the open arm of the EPM in prairie voles. Auto-grooming, which may also be indicative of anxiety, also was quantified during the EPM test.…”

Consequences of Early Experiences and Exposure to Oxytocin and Vasopressin Are Sexually Dimorphic

“…3) groups were tested for alloparental behavior following weaning they often failed to attend to the pups and in some cases attacked the pups. Female prairie voles are less likely to be spontaneously alloparental and females from these various rearing groups did not differ in alloparenting, although MAN0 females were less likely than MAN1 females to form pair bonds, even after extended periods of cohabitation with a partner [Bales et al, 2007a].…”

“…In prairie voles, behavioral manipulations, created by different methods of handling the parents or offspring in the postnatal period, had life-long consequences for behavior and physiology [Bales et al, 2007a] ( table 1 ). In a series of experiments, we have examined the effects of differential neonatal behavioral treatments of infants and family on later behavioral and neuroendocrine responses.…”