Dysregulated hippocampal fatty acid metabolism following intermittent hypoxemia-induced neonatal brain injury is rescued by treatment with acetate

The brain is a lipid-rich organ that experiences rapid growth and development after birth in a period hallmarked by extensive lipid synthesis. We still lack a fundamental understanding of lipid metabolism during this critical time of brain development and how these dynamics occur in infants born extremely preterm (<28 weeks of gestation) suffering from brain injuries. Using an established model of neonatal brain injury due to intermittent hypoxemia, we recapitulate hippocampal-dependent cognitive impairments and examine the extent of changes in the brain's lipid profile. Our results show changes in hippocampal lipid composition and abnormal fatty acid profile. Furthermore, we provide evidence of an increase in mitochondrial fatty acid β-oxidation, a process that is not classically thought of occurring in the developing brain. We find that a specific alternative fuel, acetate, spares fatty acids from mitochondrial β-oxidation. Here, we show that treatment with acetate in vivo in the form of glycerol-triacetate promotes functional recovery and restores hippocampal fatty acid profile after neonatal brain injury.