Organoids and neuron transplants give new ways to study the brain

STUDYING THEAAAS human brain is hard. Other animals’ brains provide clues. But they cannot reveal the special essence that makes human brains different. Nor, often, do they make good models for neurological conditions that affect human beings.Recently, however, two halfway-house approaches have been developed. One is to grow so-called brain organoids from human tissue. The other is to create animals with human-derived neurons in their bodies. As the heard, both approaches are yielding results. But they also raise ethical questions of their own.