Multimodal Single-Cell Analysis Reveals Physiological Maturation in the Developing Human Neocortex

Abstract

In the developing human neocortex, progenitor cells generate diverse cell types prenatally. Progenitor cells and newborn neurons respond to signaling cues, including neurotransmitters. While single-cell RNA sequencing has revealed cellular diversity, physiological heterogeneity has yet to be mapped onto these developing and diverse cell types. By combining measurements of intracellular Ca2+ elevations in response to neurotransmitter receptor agonists and RNA sequencing of the same single cells, we show that Ca2+ responses are cell-type-specific and change dynamically with lineage progression. Physiological response properties predict molecular cell identity and additionally reveal diversitynot captured by single-cell transcriptomics. We find that the serotonin receptor HTR2A selectively activates radial glia cells in the developing human, butnot mouse, neocortex, and inhibiting HTR2A receptorsin human radial glia disrupts the radial glial scaffold. We show highly specific neurotransmittersignaling during neurogenesis in the developing human neocortex and highlight evolutionarilydivergent mechanisms of physiological signaling.