Multiplexed Metabolic Labeling of Glycoconjugates in Polarized Primary Cerebral Cortical Neurons.

The spatial distribution of cell-surface glycoconjugates in the brain changes continuously, reflecting neurophysiology especially in the developing phase, but their functions and fates mostly remain unexplored. Their spatiotemporal distribution is particularly important in polarized neuronal cells, such as cerebral cortical neurons composed of a soma and neurites. In this work, we dually labeled sialic acid (Sia5Ac) and N-acetylgalactosamine/glucosamine (GalNAc/GlcNAc) by a neurocompatible strategy of metabolic glycan labeling, metabolism-by-tissues (MbT), and obtained the multiplexed information on their spatiotemporal distribution on polarized cortical neurons. The analyses showed the preferentially distinct distribution of each saccharide set at the late developmental stage after randomized, heterogeneous distribution at the early stage, suggesting that Sia5Ac and GalNAc/GlcNAc are translocated anisotropically during neuronal development.