Figure 5

MCT8 expression in neurons. (A–D) Immunostaining of 10-week-old organoid for SATB2 (upper layer neuron marker) and CTIP2 (deep layer neuron marker) shows that cerebral organoids recapitulate the laminar organization of the CP with early born deep layer neurons populating inner regions of the CP whereas later born upper layer neurons are enriched in peripheral regions. Dashed lines mark the border between VZ, SVZ and CP. (E–G) High magnification views of the boxed regions highlighted in (A). Note that expression of the upper layer marker SATB2 is strong in basally positioned neurons (E), much weaker in deeper CP regions (F) and almost undetectable in newborn neurons within the SVZ (G). (H–K) In 9-week-old organoids, large field columnar views show abundant MCT8 immunostaining throughout the CP including deep regions populated by deep layer neurons (H,I) and peripheral regions populated by upper layer neurons (J,K). (L) Delineation of individual neuronal cell bodies and processes is difficult in the densely populated CP but high magnification views of CP regions confirms MCT8 membrane expression of cortical neurons. Scale bars: 100 µm (A–D,H–K), 20 µm (E–G), 10 µm (L).