ABOVE: Brain organoid
NATIONAL INSTITUTES OF HEALTH/ VACCARINO LAB, YALE UNIVERSITY
Tens of millions of Americans suffer each year from neurological and psychiatric disorders. While scientists’ understanding of the human brain continues to advance, effective treatments remain hobbled by the models researchers use to study neurological diseases.
A report, released April 8 by the National Academies of Sciences, Engineering, and Medicine, considers the ethical considerations of three emerging models for studying the human brain: human neural organoids, cell transplants, and chimeras. Neural organoids are in-vitro, three-dimensional collections of human brain cells that mimic many features of the fetal brain. Both transplants and chimeras involve the introduction of human brain cells into nonhumans animals, but while transplants can be done during many phases of development, chimeras are created when human stem cells are injected into an animal very early in its development, such that they integrate more fully and grow in parallel ...