FOXG1 spatiotemporally orchestrates subtype fate specification and patch/matrix identity of striatal spiny projection neurons.

Loss of Foxg1 in progenitors causes both dSPNs and iSPNs to adopt an eSPN fate in the striatum.

• Why it matters: Understanding how striatal neuron subtypes are specified is crucial for insights into brain development and related disorders, especially for the recently identified eSPNs whose origins are unclear.
• What they did: Using single-cell RNA sequencing and loss-of-function approaches, the study shows Foxg1 promotes dSPN and iSPN fates while suppressing eSPN fate, and its deletion forces progenitors into an eSPN identity.
• The result: Foxg1 regulates transcriptional programs and molecules involved in cell migration and adhesion, providing mechanisms for subtype specification and patch/matrix patterning in the striatum.