Stanford researchers replace large portion of mouse brain with human brain organoid cells
A Stanford University team genetically wiped out a large portion of a mouse brain and replaced it with human brain organoid cells, a possible way to study brain organoids in a more natural context, Ars Technica reports.
The approach is intended to address a limitation in organoid research. In recent years, organoids have drawn excitement as models for human disease. These small patches of tissue are formed using stem cells, and they appear to produce many of the same cell types and at least some of the structures normally formed in actual organs. That makes them a better model for diseases that rely on the sometimes complex interactions among multiple specialized cell types that are a feature of the human body.
But even the most sophisticated organoids lack a lot of the features of a real human body. Brain organoids are especially limited. They do not form any of the connections with specialized brain structures needed to behave "normally."
The Stanford group's method places human brain organoid cells into a mouse brain after a large portion of the mouse brain has been genetically wiped out. Organoids provide a much better model for an intact tissue than simply having a bunch of disassociated cells lying flat on a culture dish, because they adopt a three-dimensional tissue structure and consist of various specialized cells.
The limitations remain. Organoids are not hooked up to a circulatory system that allows the liver to process chemicals the organoid produces. They also do not have immune cells moving through them, Ars Technica reported.