English: "Advances in 3D cell culturing provide the foundation for systems to explore organoid intelligence. (A) 3D neural cell cultures have important advantages for biological learning, compared with conventional 2D monolayers – namely a far greater density of cells, enhanced synaptogenesis, high levels of myelination, and enrichment by cell types essential to learning. (B) Brain organoid differentiation over time from 4 to 15 weeks, showing neurons (microtubule associated protein 2 [MAP2]; pink), oligodendrocytes (oligodendrocyte transcription factor [OLIG2]; red), and astrocytes (glial fibrillary acidic protein [GFAP]; green). Nuclei are stained with Hoechst 33342 (blue). Images were taken with an LCM 880 confocal microscope with 20x and 63x magnification. Scale bars are 100 μm and 20 μm, respectively. The images show the presence of MAP2-positive neurons as early as 4 weeks, while glial cells emerge at 8 weeks and there is a continuous increase in the number of astrocytes over time."