Investigating peripubertal stress and exogenous corticosterone as endogenous stimulators of brain metabolism

Substantial research on the association between early-life stress and its long-lasting impact on lifetime mental health has been performed revealing that early-life environmental adversity strongly regulates brain function. Alterations of gene expression and behavior in the off-springs of paternally stressed rats were also revealed. However, the precise mechanisms underlying these changes remain poorly understood. Here, an improved characterization of these processes from investigations of the functional metabolism of animal models exposed to peripubertal stress (PS) is proposed. The ultimate goal of this study was to bring forward functional Magnetic Resonance Spectroscopy (fMRS) as a technique of interest for a better understanding of brain areas by endogenous stimulators such as stress. The present study evaluated, compared and classified effects of individual PS (iPS) and paternal PS (pPS) under corticosterone (CORT) challenge in the septal areas of adult rats. Acute stress was simulated by injection of CORT and metabolic concentration changes were analyzed as a function of time. Evaluation of Glucose and Lactate concentration changes allowed the classification of groups of rats using a Glc to Lac index. Moreover, metabolic responses of control rats (CC) and of pPS x iPS rats (SS) were similar while responses in pPS (SC) and iPS (CS) differed, revealing differential adaption of energetic metabolism and of glutamatergic neurotransmission. Findings have crucial interest for understanding the metabolic mechanisms underlying altered functional connectivity and neuronal plasticity in septal areas inducing increased aggressivity in early-life stressed rats.