Developmental emergence of first- and higher-order thalamic neuron molecular identities.

The thalamus is organized into nuclei that have distinct input and output connectivities with the cortex. Whereas first-order (FO) nuclei - also called core nuclei - relay input from sensory organs on the body surface and project to primary cortical sensory areas, higher-order (HO) nuclei - matrix nuclei - instead receive their driver input from the cortex and project to secondary and associative areas within cortico-thalamo-cortical loops. Input-dependent processes have been shown to play a crucial role in the emergence of FO thalamic neuron identity from a ground-state HO neuron identity, yet how this identity emerges during development remains unknown.

Single-cell transcriptional logic of cell-fate specification and axon guidance in early-born retinal neurons.

Retinal ganglion cells (RGCs), cone photoreceptors (cones), horizontal cells and amacrine cells are the first classes of neurons produced in the retina. However, an important question is how this diversity of cell states is transcriptionally produced. Here, we profiled 6067 single retinal cells to provide a comprehensive transcriptomic atlas showing the diversity of the early developing mouse retina.

Transcriptional Dysregulation in Postnatal Glutamatergic Progenitors Contributes to Closure of the Cortical Neurogenic Period.

Progenitors of cortical glutamatergic neurons (Glu progenitors) are usually thought to switch fate before birth to produce astrocytes. We used fate-mapping approaches to show that a large fraction of Glu progenitors persist in the postnatal forebrain after closure of the cortical neurogenesis period. Postnatal Glu progenitors do not accumulate during embryonal development but are produced by embryonal radial glial cells that persist after birth in the dorsal subventricular zone and continue to give rise to cortical neurons, although with low efficiency.