Neuroscientists have come a step closer to artificially producing humans and may have even crossed ethical lines by growing lumps of the human brain in the lab, researchers argue.
The creation of mini-brains or brain "organoids", and in some cases transplanting the tissue into animals, has become one of the hottest fields in neuroscience, researchers said, with some of the blobs of tissue, which are only pea-sized and made of stem cells, even developing spontaneous brain waves similar to those seen in premature babies.
According to scientists, the development of organoids has the potential to transform medicine by allowing them to probe the living brain like never before but as much controversy because it is unclear where it may cross the line into human experimentation.
"If there's even a possibility of the organoid being sentient, we could be crossing that line. We don't want people to do research where there is potential for something to suffer," The Guardian quoted Elan Ohayon, the director of the Green Neuroscience Laboratory in San Diego, as saying.
The difficulty in studying live human brains may be overcome through organoids, which can help investigate schizophrenia and autism, and why some babies develop small brains when infected with Zika virus. The organoids will not only be used to study brain disorders such as Alzheimer's and Parkinson's, and eye conditions such as age-related macular degeneration, but will even be sent to space to study how the human brain developed in zero-G.
Ohayon and his colleagues Ann Lam and Paul Tsang will, however, argue in their presentation to the Society for Neuroscience meeting in Chicago that checks must be in place to ensure that these organoids do not experience suffering.
Harvard researchers in a recent study showed that brain organoids developed a rich diversity of tissues such as cerebral cortex neurons and retinal cells. If they are grown for eight months these organoids developed their own neuronal networks that responded when a light shone on them.
Another study led by Fred Gage at the Salk Institute in San Diego saw transplantation of human brain organoids into mouse brains to investigate whether they connect to the animal's blood supply and sprouted fresh connections.
Ohayon, however, argued that studies aimed to put human brain organoids into animals must be frozen as there was a reasonable chance of organoids becoming able to perceive or feel things.
Scientists, philosophers, and authors including Hank Greely, director of the Center for Law and the Biosciences at Stanford University in California, in an ethical debate last year said organoids were not yet sophisticated enough to raise immediate concerns but added that it was time to start discussing guidelines.
Referring to the character in Franz Kafka's "The Metamorphosis", who wakes up to find he is a giant insect, Greely continued the "potential to perceive or to react to things" seemed likely to him, and believed the concerns were serious if organoids perceived and reacted to stimuli that caused pain.