Scientists from Vienna have worked for four years and finally come up with a small blob of human brain tissue that has been created from stem cells. These human brain organoids as they are called, are capable of pulsing with electrical activity and also create new nerve cells or neurons. In short, these blobs of tissue that are as small as a single grain or rice are capable of acting like a complete human brain.
The tissues can also develop into the six layers of the brain cells that form the main part of the brain called the cortex. These allow humans to think, judge and provide cognitive abilities.
The problem that arises with these brain tissues that have developed from stem cells is the ethical question. On one hand, these tissues may be a boon for people with dementia, Alzheimer’s disease or other progressive or infective brain diseases. On the other hand, the ethics of developing a brain outside the body that could probably think on its own some day is a muddy issue right now, say experts.
While many believe that this issue needs to be analyzed and discussed so that a middle path that benefits humans without risking our very existence is warranted, others believe that science is advancing too fast for ethics to keep tabs on its progress.
The researchers for example, now are providing the brain tissue that they have developed with a blood supply that can nourish it and help it to grow. Another experiment involves transplanting these brain organoids into mice. Ethics organizations are uncomfortable with the fact that a developing human brain could be transplanted into a mouse.
The implications could be far reaching they fear. This human brain organoid may become fully functional and develop systematically in the rodent. Researchers however believe that growing these brain tissues may help understand diseases such as autism, schizophrenia, epilepsy etc.
At present the National Institutes of Health does not fund projects or allow projects where human stem cells can be developed into embryos. However, they do not have any regulations regarding development of organoids and their transplantation into other vertebrate animals such as these lab mice.
Two papers were presented at the annual meeting of the Society for Neuroscience in Washington, D.C. that said that human brain organoids have been successfully transplanted to lab rodents and in one case they have survived for two months. Fred Gage of the Salk Institute, a neurobiologist led the team that performed these experiments. The organoids were successfully connected to the blood vessels of the mice that helped them grow and develop.
The researchers explain that the mice brain cannot even host a full-grown child’s brain.
So, any fears regarding the developing brain are baseless. These brain organoids would not develop beyond a point but that they are humanoid and some researchers speculate that if these organoids can think for themselves, the question of ethics arises. Deeper thinking on this is necessary.