Stuart Little, rat with human brain have been developed in US laboratories. Scientists have managed to integrate human brain cells into rat brains.Tiny brain “organoids,” or clusters of neurons grown from human stem cells, have been implanted into rats .
It emerged that scientists are integrating clusters of human brain cells into rodent brains in a bid to treat a number of illnesses from Alzheimers to Zika. The respected MIT Technology Review reported researchers have used contoversial stem cell techniques to grow tiny clumps of human brain called organoids.
These organoids have been almost routinely inserted into rat brains and connected to a blood supply – effectively transplanting the brain of the donor h.uman into a rat. In a scenario straight out of a horror movie some of these organoids have then grown physical connections with the host rat brain – creating a human-rat mutant.
The results, to be announced at the annual meeting of the Society for Neuroscience in Washington, D.C., have been promising so far, Stat reports. Organoids from human stem cells have not only formed connections to the rat brains, but other researchers have managed to connect them to retinal cells and get a response. Harvard University geneticist George Church says that he’s managed to vascularize, or grow blood veins, in brain organoids. All the evidence seems to suggest that the organoids really do work, if not exactly like a human brain, at least well enough to run experiments on.
The success of these experiments, and the prospect of more and bigger human brain cells being transplanted to bigger animals has led to a mass of ethical questions – not least do the organoids have consciousness? And when does a rat stop being a rat and start being a human?
It’s also a chance to peer further into the murky depths of consciousness itself. A rat-human hybrid would certainly blur the line between human and animal consciousness, bringing us that much closer to figuring out what it is that makes us human.
Stanford bioethicist Hank Greely said: “People are talking about connecting three or four but what if you could connect 1,000? “That would be getting close to the number of cells in a mouse brain.“At some future point it could be that what you’ve built is entitled to some kind of respect.”The situation is so acute that at least one laboratory – the joint Havard-MIT George Church synthetic biology lab employs a full-time Bioethicist.
Some ethicists argue that we can no longer perform experiments on them as we have been in recognition of their greater humanity.