Mice with human brain cells offer a tool to study disease. Ethicists ask: What's next?

Neuroscientists have made a major advance in modeling the human brain in mice, offering a new way to study conditions like cerebral palsy. Ethicists ask if it changes how these mice should be treated.

<img src='https://npr.brightspotcdn.com/dims3/default/strip/false/crop/3609x2733+0+0/resize/3609x2733!/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2Fa9%2F3d%2F35c831fd4f07b32ff9fbdfc6dfbf%2Fmouse-brain-crop.jpg' alt='This side view of a lab mouse brain shows nerve fibers extending from the human graft (colored with green and red fluorescent proteins) through the mouse brain (colored with blue). Scale bar = 1 mm.'/><p>Neuroscientists have made a major advance in modeling the human brain in mice, offering a new way to study conditions like cerebral palsy. Ethicists ask if it changes how these mice should be treated.</p><p>(Image credit: S. Pașca lab)</p><img src='https://media.npr.org/include/images/tracking/npr-rss-pixel.png?story=nx-s1-5968873' />