Spectroscopic Profile of Metabolome Dynamics During Rat Cortical Neuronal Differentiation

Neuronal differentiation is a highly dynamic process marked by coordinated biochemical, structural, and metabolic changes. Rat primary cortical neurons are the preferred cell model to study this process as they can maintain their functional attributes, including functional synapses, and simulate the behavior of neuronal cells in vivo. In this study, we employed Fourier transform infrared (FTIR) spectroscopy to monitor the molecular transformations that occur during the differentiation of rat cortical neurons. Partial least squares regression (PLS-R) analysis from the 1800-1500 cm^-1 region further allows the identification of the spectroscopic profile of early and late differentiation stages, highlighting the technique's ability to detect subtle molecular changes. Further peak intensity analysis revealed significant changes in the cells' metabolome during differentiation; it was possible to observe remodeling of protein secondary structures and an increase in protein phosphorylation levels, which can imply activation of signaling pathways essential for neuronal differentiation and maturation. Concomitantly, lipid-associated spectral regions demonstrated increased levels of total lipids, lipid esters, and longer acyl chains and decreased unsaturation levels, alterations that can be linked to membrane expansion throughout neuronal differentiation. These findings underscore FTIR spectroscopy as a valuable tool for studying neuronal differentiation, offering insights into the conformational and metabolic shifts underlying the formation of mature neuronal phenotypes.