Abstract
Chronic stress during the developmental period of adolescence increases susceptibility to many neuropsychiatric diseases in adulthood, including anxiety, affective, and alcohol/substance use disorders. Preclinical rodent models of adolescent stress have produced varying results that are species, strain, sex, and laboratory-dependent. However, adolescent social isolation is a potent stressor in humans that has been reliably modeled in male rats, increasing adult anxiety-like and alcohol drinking behaviors, among others. In this study, we examined the generalizability and sex-dependence of this model in C57BL/6J mice, the most commonly used rodent strain in neuroscience research. We also performed a parallel study using social isolation in adulthood to understand the impact of adult social isolation on basal behavioral phenotypes. We found that 6 weeks of social isolation with minimal handling in adolescence through early adulthood [postnatal day (PD) 28–70] produced a hypersocial phenotype in both male and female mice and an anxiolytic phenotype in the elevated plus-maze in female mice. However, it had no effects in other assays for avoidance behavior or on fear conditioning, alcohol drinking, reward or aversion sensitivity, or novel object exploration in either sex. In contrast, 6 weeks of social isolation in adulthood beginning at PD77 produced an anxiogenic phenotype in the light/dark box but had no effects on any other assays. Altogether, our results suggest that: (1) adolescence is a critical period for social stress in C57BL/6J mice, producing aberrant social behavior in a sex-independent manner; and (2) chronic individual housing in adulthood does not alter basal behavioral phenotypes that may confound interpretation of behavior following other laboratory manipulations.
Highlights
Adolescence is a critical developmental period marked by increased reward-seeking and impulsivity and the establishment of apposite social behaviors (Spear, 2004; Steinberg, 2004, 2010; Romer, 2010; Leshem, 2016)
These results suggest that extended single housing beginning in adulthood does not robustly impact the basal behavioral state of C57BL/6J mice and that adolescence is a sensitive period for the effects of chronic social stress in this strain
Social isolation during adulthood did not alter anxiety-like behavior on the elevated plus maze (EPM) (Figure 2B)
Summary
Adolescence is a critical developmental period marked by increased reward-seeking and impulsivity and the establishment of apposite social behaviors (Spear, 2004; Steinberg, 2004, 2010; Romer, 2010; Leshem, 2016). As peer interactions are especially important during adolescence (Steinberg, 2004; Jager et al, 2015), exposure to social stress may have deleterious consequences on brain development and behavior (Casey et al, 2010; Platt et al, 2013; Burke et al, 2017) This increased stress sensitivity may partly explain why substance use disorders and many other psychiatric conditions frequently emerge during adolescence (Turner and Lloyd, 2004; Kessler et al, 2005, 2007; Ernst and Fudge, 2009; Casey and Jones, 2010; Blakemore and Robbins, 2012). Understanding how adolescent social stress alters neurophysiology and behavior may prove crucial to treating stress-related disorders in adolescence and throughout later life
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
