Menard, Janet
Exposure to Stress During Adolescence Alters Safety Learning and Emotional Behaviours that Persist into Adulthood
Stress during adolescence has profound effects on psychological, behavioral, and neurobiological outcomes in adulthood. This study investigates the impact of adolescent stress on safety learning, anxiety- and depressive-like behaviors, and associated neurocircuitry using a rat model. Adolescent male Long Evans rats underwent an unpredictable intermittent stress regimen, followed by behavioral testing and immunohistological analyses in adulthood. It was confirmed that stress impaired safety learning and increased fear generalization. Behavioral assays revealed heightened anxiety- and depressive-like phenotypes in stressed rats, evidenced by reduced open-arm exploration in the elevated plus maze and increased immobility in the forced swim test, although limited changes in sucrose preference were noted during habituation. Immunohistological findings showed reductions in hippocampal neurogenesis (DCX+ cells) and disruptions in GABAergic interneuron plasticity (PV+/PNN+ populations) within the medial prefrontal cortex. These alterations suggest that adolescent stress leads to long-term changes in brain regions associated with emotional regulation and stress resilience.
Author Keywords: Adolescencent Stress, Anxiety-like Behaviour, Hippocampus, Medial Prefrontal Cortex, Neuroplasticity, Safety Learning