Early-life adversity induces metabolic alterations in a rodent model of depression: a differential stress response perspective

OBJECTIVE: Investigating metabolic differences between pre-pubertal Flinders sensitive (FSL) and resistant (FRL) line rats and determine the impact of early-life adversity on these differences. METHODS: Untargeted metabolomic profiling of whole-brain tissue from postnatal day 25 Flinders line rats, exposed to maternal separation with early weaning (MSEW), or not, was done by using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). RESULTS: Irrespective of MSEW, FSL rats had higher urea and lower glutamine, norvaline and valine concentrations than age-matched FRL controls. Across strains, MSEW reduced gamma-aminobutyric acid (GABA), glutamate, glutamine, lactate, phenylalanine, norvaline and valine concentrations, whist elevating 2-keto-3-methylbutyric acid, glycerophosphate, and urea. This effect was most pronounced in FRL rats. CONCLUSION: Pre-pubertal FSL rats displayed distinct metabolic signatures associated with altered energy and amino acid metabolism. Early-life stress further disrupts these pathways, highlighting key metabolites as potential targets in the expansion of the biological constructs underlying the pre-pubertal FSL/FRL model.