Poster abstracts
Poster number 54 submitted by Chloe Page
Adolescent stress disrupts the maturation of anxiety-related behaviors and alters the developmental trajectory of the prefrontal cortex in a sex- and age-specific manner
Chloe E. Page (Neuroscience Graduate Program), Laurence Coutellier (Ohio State University, Departments of Neuroscience and Psychology)
Abstract:
The prefrontal cortex (PFC) undergoes significant developmental changes during the adolescent period. Specifically, there is functional maturation of the GABAergic system, including increased parvalbumin (PV) expression and density of perineuronal nets (PNNs), which contribute to a shift in prefrontal excitatory/inhibitory (E/I) balance in favor of increased inhibition and stability. These developmental changes correlate with the maturation of PFC-dependent functions, including emotional regulation and cognitive abilities. Chronic stress during adolescence is a major risk factor for affective disorders such as anxiety and depression, possibly by disrupting GABAergic development and the maturation of cognitive and emotional functions. However, the impact of adolescent stress on GABAergic maturation is not well understood, nor are the possible mediating effects of sex differences. Additionally, it is unknown whether adolescent stress differentially perturbs prefrontal E/I balance in the short-term (adolescence) compared to the long-term (adulthood). Here we test the hypothesis that adolescent stress disrupts the developmental trajectory of the PFC in a sex- and age-specific manner. To this end, we exposed male and female mice to two weeks of unpredictable chronic mild stress during adolescence (post-natal day [PND] 28-42). One cohort was tested for emotional and cognitive behaviors and molecular changes in the PFC 24 hours following the cessation of stress (starting PND 43); a separate cohort was tested in adulthood (starting PND 60). We observed that anxiety-related behaviors declined with age in control animals, while animals stressed in adolescence showed persistently elevated anxiety-like behaviors. Cognitive function was also impaired in adult males stressed in adolescence, with no effect on females. Male mice also showed decreased PV cell counts and altered expression of the N-methyl-D-aspartic acid (NMDA) receptor subunits NR2B and NR2A in adulthood. By contrast, female mice showed increased PNN coverage of PV cells in adolescence and no changes in NR2 subunit expression. The findings presented here provide evidence for sex- and age-specific effects of adolescent stress on emotional and cognitive behaviors and on the maturational processes that affect prefrontal E/I balance.
References:
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Keywords: parvalbumin, perineuronal nets, chronic stress