Comparison of Parental Behavior and Offspring's Anxiety Behavior Using a Reciprocal F1 Hybrid Model

Abstract

ABSTRACT. Emotional behavior can be characterized by interactions between genes and environments, especially in the developmental period. However, in mice, the effects of paternal care on offspring's emotional development are not well understood even in cases in which the male mice show stable paternal care to the pups. In this study, we used a reciprocal hybrid model of C57BL/6 and BALB/c mice, which show different parental behaviors and emotional responses, and compared the emotional responses in pups in their adulthood by using the elevated plus-maze test. It was found that inbred male mice showed intensive parental behavior toward their pups, especially as parental contact behavior, and that the licking/grooming behavior of males was dependent on the strain of the female they were paired with. Also, BALB/c pairs showed less parental contact behavior than C57BL/6 pairs. In the elevated plus-maze test, BALB/c males and females showed higher anxiety behavior, and reciprocal hybrid offspring showed intermediate values between C57BL/6 and BALB/ c mice. Although no significant difference was found in the parental care that offspring received and anxiety-related behavior between the two reciprocal hybrid strains, BALB/c pairs showed less parental contact behavior toward the pups as compared to C57BL/6 pairs, which would be associated with the higher anxiety-related behavior exhibited in the adulthood of BALB/c strain.KEY WORDS: anxiety, maternal care, mice, paternal care, reciprocal F1 hybrid.J. Vet. Med. Sci. 72(12): 1589-1596, 2010 Social environments during the early stages of life, in addition to genetic variations, have long-lasting influences on the behavioral development of individuals. The motherpup interaction has especially strong influences on the behavioral characteristics of rodent offspring in their adulthood [6,26]. For example, anxiety and maternal behavior are associated with maternal care offspring received in their infant period [8,27]. Another thing is that maternally deprived pups show persistent stress-endocrine response, suggesting deficiencies in their negative feedback system [32]. We have shown that early weaned mice and rats deprived of maternal care in the neonatal period as well as in the postnatal period of day 15 to day 21 display reduced maternal behavior [23] and increased anxiety-related behavior [20,21]. Classic studies in mice kept in semi-natural environments showed bi-parental care and monogamous breeding colonies [9, 31], indicating that not only maternal care, but also paternal care comprises important social stimuli for the developing pups. It is unfortunate that the effects of paternal care on the behavioral development of offspring have not been well documented.The genetic influences on behavioral development have been well demonstrated. Some studies have assessed genomic influences on behavior using hybrid F1 mice. For example, offspring from different genetic strains showed different levels of anxiety even though they received mothering from a mother of the same strain [...

Pairmate-dependent pup retrieval as parental behavior in male mice

“…Although a number of animal models have been used in experimental studies of parental care (Reburn and Wynne-Edwards, 1999; Carter et al, 2009; de Jong et al, 2009; McGraw and Young, 2010; Ozawa et al, 2010; Kuroda et al, 2011; Mogi et al, 2011; Saltzman and Maestripieri, 2011; Lambert et al, 2013; Tachikawa et al, 2013; Yoshida et al, 2013), given its value for genetic studies, a mouse model of paternal behavior may be especially useful (Hager and Johnstone, 2003; Jin et al, 2007; Liu et al, 2013). While some strains of the laboratory mouse Mus musculus become biparental (Wright and Brown, 2000; Chourbaji et al, 2011), a phenomenon called sensitization (Rosenblatt, 1967; Rosenblatt et al, 1996), little information is available regarding the factors that specifically induce male parental behavior (Gubernick and Alberts, 1987, 1989; Lonstein and De Vries, 2000; Kentner et al, 2010; Leuner et al, 2010).…”

Inborn vs. acquired anxiety in cross-breeding and cross-fostering HAB/LAB mice bred for extremes in anxiety-related behavior.

“…Along the same line, chronically stressed pregnant mouse dams showed both increased anxiety and maternal care (Maestripieri, Badiani, & Puglisi-Allegra, 1991), and, in human mothers, a high state anxiety has been related to a high level of child-directed protective behaviors (Coplan, Arbeau, & Armer, 2008; Rubin, Burgess, & Hastings, 2002; Numan & Insel, 2003). Paternal care could also play a role in this context (Ozawa, Kikusui, Takeuchi, & Mori, 2010). Despite limited interspecies comparability, such associations can play a protective role passing on the “knowledge” of parents to their offspring, for instance, fear-related experience (Dias & Ressler, 2014), thus serving for better adaptations to the current environment and giving an opportunity for flexible responses to its changes.…”