The multiple facets of Cajal-Retzius neurons

ABSTRACT Cajal-Retzius neurons (CRs) are among the first-born in developing cortex of reptiles, birds and mammals, including humans. The peculiarity CRs lies fact they initially embedded into immature neuronal network before being almost completely eliminated by cell death at end cortical development. best known for controlling migration glutamatergic formation layers through secretion glycoprotein reelin. However, have been shown to play numerous additional key roles many steps development, spanning from patterning sizing functional areas synaptogenesis. use genetic lineage tracing has allowed discovery their multiple ontogenetic origins, migratory routes, expression molecular markers dynamics. Nowadays, single-cell technologies enable us appreciate heterogeneity with an unprecedented resolution. In this Review, we discuss morphological, electrophysiological, criteria allowing identification CRs. We further expose various sources, trajectories, developmental functions dynamics Finally, demonstrate how analysis public transcriptomic datasets allows extraction signature throughout transient life consider within across species.