Maternal influences on adult stress and anxiety‐like behavior in C57BL/6J and BALB/CJ mice: A cross‐fostering study

Abstract

The quality of maternal care during early life has a dramatic impact on later stress reactivity and anxiety. Two inbred mouse strains, C57BL/6J and BALB/cJ, differ in levels of maternal care, stress reactivity, and anxiety-like behavior in adulthood. However, the relative contribution of early environmental factors and genetic predisposition to differences in these strains is not known. Maternal care, plasma corticosterone levels, emotionality, and hippocampal and paraventricular nucleus (PVN) glucocorticoid receptor mRNA levels were measured in adult C57BL/6J and BALB/cJ mice. Litters were then cross-fostered and anxiety-like behavior and stress reactivity was assessed in adulthood. Significantly less maternal care and elevated stress-induced corticosterone and emotionality was observed in BALB/cJ compared to C57BL/6J mice. Yet, no strain differences were found in hippocampal or paraventricular nucleus glucocorticoid receptor mRNA levels. Cross-fostering did alter anxiety-like behavior and basal corticosterone levels, which suggests that while genetic differences account for some of the variations between these two strains early rearing conditions also contribute. ß 2005 Wiley Periodicals, Inc. Dev Psychobiol 48: 95-96, 2006.

Differential gene body methylation and reduced expression of cell adhesion and neurotransmitter receptor genes in adverse maternal environment

“…Although many genetic tools are available for the mouse, establishing early life adversity paradigms with robust and reproducible behavioral outcomes is challenging in this species. 5, 6 We have recently developed a mouse model of maternal adversity, which is based on a deficit in the maternal 5-HT 1A receptor (R) and which causes innate anxiety, increased stress reactivity and impaired vocal communication in the offspring. 7, 8 This model has construct validity because reduced binding of 5-HT 1A R has been found in depression, including peri/postpartum depression, a condition that can represent early life adversity for the offspring.…”

Early life stress increases anxiety-like behavior in Balbc mice despite a compensatory increase in levels of postnatal maternal care

“…The availability of transgenic animals and commercial platforms for conducting unbiased genomic and proteomic screens make the mouse an attractive model organism to study this problem rigorously. However, the establishment of ELS paradigms that are associated with robust and reproducible behavioral outcome in the mouse has proven to be a challenging task (Priebe et al, 2005; Millstein and Holmes, 2007), explaining the paucity of studies that have used transgenic animals or genomic tools to study this problem [for a rare example see (Carola et al, 2007)]. We hypothesized that careful monitoring of postnatal maternal care, appropriate selection of genetic background, the identification of reliable developmental markers modified by ELS, and appropriate sample size were necessary to establish a robust ELS paradigm in the mouse.…”

Effects of brief stress exposure during early postnatal development in balb/CByJ mice: I. Behavioral characterization

“…This suggest, that LMC mice may experience some level of stress as well, perhaps as consequence of nest disruption and/or maternal care changes. Previous research has given ample evidence that maternal care behavior is a significant regulator of pup behavior in correlation to HPA programming by adulthood and neonatal stress effects have been argued to result from changes in maternal care behavior, following extended separation from the pups (Kaffman & Meaney, 2007; Levine 2005; Meaney, 2001; Priebe et al 2006; Weaver, Cervoni, Champagne, D’Alessio, Sharma, Seckl, Dymov, Szyf, & Meaney, 2004, Zaharia, et al 1996). It has been generally assumed that maternal behavior, if altered, would affect the entire litter equally.…”

“…To insure, nevertheless, a sufficient stress effect in our mice, we have combined maternal separation with short exposures to cold stress, which has previously shown to be a very effective stressor (Avishai-Eliner, Yi, Newth, & Baram, 1995; Odeon, Salatino, Rodriguez, Scolari, & Acosta 2010; Yi & Baram, 1994). We chose Balb/CByJ mice for this paradigm because of their high stress responsiveness (Brinks, van der Mark, de Kloet, & Oitzl, 2007; Ducottet & Belzung, 2004; Shanks & Anisman, 1988) as well as high potential for developmental plasticity (Chapillon, Manneche, Belzung, & Caston, 1999; Priebe, Brake, Romeo, Sisti, Mueller, McEwen, & Francis, 2006; Zaharia, Kulczycki, Shanks, Meaney, & Anisman, 1996). We have chosen to include a within-litter control group (LMC) by subjecting only half of each litter to maternal separation/temperature stress while the other half of the pups remained with the dam.…”