Life in a petri dish

Brain Imaging

Ebony Garlett, Reporter

What makes us human?

Is it our brain, or our body? American TV thriller Westworld season 1 says it’s our memories. Scientists and philosophers are asking questions about consciousness, as researchers race to find the cure for disorders.

In a bid to learn more about disorders such as Parkinson’s disease and schizophrenia, researchers have gained the ability to create, grow and use mini human brains and integrate human cells in animal brains to see how they react.

Such experiments could be enormously valuable, “Yet the closer the proxy gets to a functioning human brain, the more ethically problematic it becomes,” said Nita Farahany.

Nita Farahany, Henry Greely, and 15 other co-authors have written a scientific paper to pose questions about issues that must be understood to guide this research along. Questions such as is it even possible for researchers to assess sentient capabilities of the brain surrogates and understanding what this means for things such as life and death? (Sentient meaning being able to perceive or feel things).

Specifically, the researchers are growing miniaturized, simplified versions of human brain tissue from stem cells, where they can push cells to act as particular brain regions. These different brain regions can be combined in limited ways and are called organoids.

These Organoids are becoming increasingly complex; last year, a lab at Harvard recorded neural activity from an organoid after shining light on a region where cells of the retina had formed together with cells of the brain, demonstrating that the organoid can respond to an external stimulus. This is clearly not the same as feeling distressed but it’s a significant advance.

Other researchers have transplanted human brain cells into mice and some studies have removed brain tissue from patients during surgery.

Another key point is that chimera have also been created. Chimera means something that is a blend of two different kind of organisms. In this context, they’re animals (usually mice) into which human brain cells have been implanted. The implanted cells are derived from pluripotent stem cells, like those used to make the brain organoids. This is done to provide a more physiologically relevant mode to study diseases like Parkinson’s.

When human glial cells (a type of brain cell) were transplanted into mice, the mice performed better on some learning tasks. The researchers said that though the mice seem smarter, the shape of their skull restricted the brain from growing further. Very ‘Pinky and the brain’ my eyes.

The authors wrote, “We believe that decisions about which kinds of chimera are permitted or about whether certain human organs grown in animals make animals ‘too human-like’ should ultimately be made on a case-by-case basis — taking into account the risks, benefits, and people’s diverse sensitivities.” This human-likeness that the authors fear is called ‘human–animal blurring’.

Researchers have already produced mice with rat pancreases by injecting rat pluripotent stem cells into mouse embryos. The same approach could one day enable the production of human organs in other animals.

Farahany and the fellow authors said “To ensure the success and social acceptance of this research long term, an ethical framework must be forged now.” The authors concluded by saying that the experimental models of the human brain could help to unlock mysteries about psychiatric and neurological illnesses that have long remained unknown.

The main question being asked is does that tissue deserve any of the protections routinely given to human or animal research subjects?

Consciousness is defined in it’s smallest form as ‘the state of being aware of and responsive to one’s surroundings’. So in relations to the incident at Harvard, would this organoid be deemed as conscious/sentient?

But it’s much more than this, it’s about also being receptive to the cold or twitching when being touched. Will these miniature organs need affection and care like most newly forming creatures? Will this affect the personality part of the brain?

Will it need love? Could it end the debate between nature vs. nurture? The article poses more questions then it answers but an open discussion is the only democratic way to move forward.