Scientists Develop Brain Organoids with Optic Cups

Article: Brain organoids develop optic cups that respond to light
Source: Cell Press, via EurekAlert
Published: August 17, 2021
Article: Scientists Grew Stem Cell 'Mini Brains'. Then, The Brains Sort-of Developed Eyes
Source: ScienceAlert
Published: August 17, 2021
Article: Human Brain Organoids Develop Optic Vesicles, Respond to Light
Source: Genetic Engineering & Biotechnology News
Published: August 18, 2021

Brain organoids with optic cups

Organoids are miniature organs grown from induced pluripotent stem cells (iPSCs) that share enough characteristics with the source organ to serve as models to study tissue and embryonic development, disease pathophysiology, and personalized therapies/therapeutics. Researchers studying the connection between the eyes and the brain have grown brain organoids that developed bilateral optic cups, the rudimentary structures that later become the eyes. Previous studies by other research teams had used human embryonic stem cells or alternatively iPSCs (which are derived from adult cells that have been genetically reprogrammed back into an embryonic-like pluripotent state) to generate the optic cup; these studies focused on generating only the retina. The present research instead seeks to study the interorgan interaction of optic cups as they are functionally integrated into brain organoids. Using cells from four iPSC donors, they developed 16 independent batches and generated 314 brain organoids, 72% of which formed optic cups (showing that the method is reproducible). Their lab protocol, such as adding retinol acetate to the culture medium to encourage eye development, produced brain organoids that formed optic cups as early as 30 days, with more mature visible structures appearing within 60 days, a time frame that parallels retinal development in human embryos. The optic cups matured enough to contain primitive corneal epithelial and lens-like cells, as well as retinal pigment epithelia, retinal progenitor cells, synapsin-1, CTIP-positive myelinated cortical neurons, microglia, and axon-like projections that formed electrically active neuronal networks. Furthermore, these organoids exhibited photosensitive response to various light intensities and connectivity to brain regions. Because the formation of optic cups within brain organoids is novel, the researchers report this being the first time observing nerve fibers of retinal ganglion cells reach out to connect with their brain targets in an in vitro system. The team is working on strategies to extend the viability of the organoids and hopes that these organoids will aid in the study of retinopathies, neurodevelopmental disorders, and tissue transplantation.

My rating of this study: ⭐⭐

Gabriel E, Albanna W, Pasquini G, et al. "Human brain organoids assemble functionally integrated bilateral optic vesicles." Cell Stem Cell.  17 August 2021. https://doi.org/10.1016/j.stem.2021.07.010