Researchers at the Seattle Brain Research Institute (Allen Institute for Brain Science) conducted an experiment to grow a human mini-brain in the body of rats and mice.
Christof Koch and his colleagues have developed a technique for creating such organelles from stem cells. A mini-brain is a miniature version of a full-fledged brain - it can only partially function as a full-fledged brain.
Organoids grown in this way, the researchers implanted in the brain of rats and mice, connecting mini-organs with blood vessels. Organoids took root well: in one case, a mini-brain, transmitting nerve signals, worked for two months.
Of course, such organs cannot be called fully functional - their structure is much simpler than that of a real brain. Researchers, however, believe that implanting a mini-brain in a rodent's brain will help develop the organoid and increase its functionality.
While there can be no question of testing this technique on humans - such experiments are fraught with serious ethical problems. No one knows how the integration of a mini-organ into the brain will affect intelligence, consciousness, and other functions.
Noticing that in some cases, mini-organelles were very closely integrated into the rodent's brain, forming connections with the cerebral hemispheres, scientists began to wonder whether such a procedure could further endow animals with consciousness or other features characteristic only for humans.
Cultivation of mini-organs usually takes place under laboratory conditions in a Petri dish, and their integration into a living organism occurs much less frequently. Organoids are already being used to study the effects of new drugs or to model various diseases.