The scientific community is in danger of surpassing (or perhaps already violating) its ethical responsibilities in the rush to study and understand the mysteries of the brain by experimenting with artificially grown substitutes, researchers warn.
Mini-brains, also known as organoids, have in recent years become an extremely important resource in neuroscience and related fields.
But while these analogues grown in stem cell laboratories are not technically considered human or animal organs, they become functionally close enough to warrant serious ethical problems – if not a direct ban on their use, according to some neurologists.
In a presentation this week to the largest meeting of neurologists in the world, a team led by researchers at the Green Neuroscience Laboratory in San Diego asked why there was an "urgent need" for scientists to develop a criteria framework that defines what " reason "so that future research using mini-brains and stem cell cultures can be bound by a developed set of ethical rules.
"Compositional and cause-and-effect features in these cultures are – in design – often very similar to naturally occurring neural substrates," the team explains in its summary.
“Recent developments in organoid studies have also led to the fact that anatomical substrates are already approaching the organization of the local network and larger structures found in living animals. "
There is a lot of evidence to support this. In recent years, scientists have promoted mini-brains as an economical and practical alternative to animal testing, and advances in stem cell cultivation have helped scientists understand how to mimic complex neurons subtypes of human brain tissue.
Cultured mini-brains on plates have allowed researchers to study the differences between humans and chimpanzees, and the rapid pace at which the field is evolving is almost frightening.
In March, scientists brewed date mini-brain – said to be approximately analogous to the complexity of the human fetal brain at 12 to 13 weeks – and in the context of their model experiment, it spontaneously contacted the nearby spinal cord and muscle tissue.
For several months later, in a separate experiment, researchers discovered electrical activity from organoids that looked strikingly similar to human brain waves.
While the scientific teams behind these incredible advances usually rush to notice that the organ is the one we are with. capable of developing today are far from showing the nervous sophistication of human and animal brains, Ohayon's calculating models and his team suggest that we are very close to growing healthy brains on a plate.
"Current organoid studies are dangerously close to the intersection of this ethical Rubicon and may have already been done," the researchers explain.
"Despite the field's understanding that the complexity and diversity of cellular elements in vivo remains unmatched by today's organoids, current cultures are already isomorphic to vital brain structure and activity in critical areas and so may be in able to support viewer activity and behavior. "
The Green Neuroscience Lab is run by Ellen Ohion and Ann Lam, two neurologists who outlined the Roadmap to a New Neuroscience: a set of basic ethical principles for their research designed to rule out" toxic methodologies ", animal experiments and methods that otherwise violate the rights, privacy, and autonomy of the individual.  From their point of view, the state of excellence in current mini-brain research means that we must afford the same kinds of protections to the primitive. or ganoids that may be complex enough to have thoughts and feelings. "
" If the organoid is even likely to be alive, we could cross that line, "Ohayon tells the Guardian ." 19659003] "We don't want people to do research where there is the potential to suffer something."
The Green team aren't the only scientists with such qualities. In a study released this month, University of Pennsylvania neurologists argue why the field needs guidelines that do not currently exist – especially in the context of an experiment nts in which organoid-grown organoids are transplanted into the bodies of host animals.
"The field is evolving rapidly and as we continue along this path, researchers need to contribute to the development of ethical guidelines based on scientific principles that determine how to approach their use before and after transplantation in animals," says neurosurgeon Isaac Chen .
"While today's brain organoids and brain organoid hosts do not come close to reaching any level of self-awareness, there is wisdom in understanding the relevant ethical considerations to avoid potential pitfalls that may arise as this progresses. technology. "
The study was presented at Neuroscience 2019, the annual meeting of the Neuroscience Society held in Chicago this week.