Anhedonic behavior and ?-amino butyric acid during a sensitive period in female rats exposed to early adversity.

ABSTRACT: Early life adversity increases depressive behavior that emerges during adolescence. Sensitive periods have been associated with fewer GABAergic interneurons, especially parvalbumin (PV), brain derived growth factor, and its receptor, TrkB. Here, maternal separation (MS) and social isolation (ISO) were used to establish a sensitive period for anhedonic depression using the learned helplessness (LH) paradigm. Female Sprague-Dawley rat pups underwent MS for 4-h/day or received typical care (CON) between postnatal days 2-20; for the ISO condition, separate cohorts were individually housed between days 20-40 or served as controls (CON2). Anhedonia was defined by dichotomizing subjects into two groups based on one standard deviation of the mean number of escapes for the CON group (<14). This approach categorized 22% of CON subjects and 44% of MS subjects as anhedonic (p?13 escapes). The number of escapes in MS subjects significantly correlated with PV and TrkB levels (PFC: r?=?0.93 and 0.91 and amygdala: r?=?0.63 and 0.81, respectively; n?=?9), but not in CON/ISO/CON2 subjects. Calretinin, but not calbindin, was elevated in the amygdala of MS subjects. These data suggest that low levels of PV and TrkB double the risk for anhedonia in females with an MS history compared to normal adolescent females.

SUBMITTER: Lukkes JL 

PROVIDER: S-EPMC6295145 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature