Transcriptomic and sublaminar dynamics of the developing human frontal cortex: A novel approach

Our recent study showed specific molecular and cellular differences in sublaminar dynamics of the dorsal/dorsolateral and orbitobasal part of the prospective human frontal cortex (Kopić et al, 2023). More particularly, during early midfetal development, dorsal part of the prospective frontal cortex showed waves of migratory cells, representing future deep projection neurons (DPN) characterized by diverse molecular markers, while orbitofrontal cortex displays "double" cortical plate pattern shown by DPN markers (TBR1, TLE4, SOX5). Cell-sparse layer in between these “two plates” shows DCX+ cells, suggesting intense neuronal migration. To further explore these early regional and laminar differences we performed NanoString GeoMx™ Digital Spatial Profiler on postmortem human fetal frontal cortical tissue to obtain novel transcriptomic data while maintaining spatial information. Our results showed novel differentially expressed genes between precisely characterized sublayers of the dorsal/dorsolateral and orbitobasal part of the prospective human frontal cortex, and such confirming an early regional patterning and specification of the human frontal cortex. Acknowledgement: This work was supported by the Croatian Science Foundation grant IP-2022-10-5975 (ŽK)