Scientists have implanted human brain tissue into fetal mice, and the result is mice with brains that are more like the human brain.
How do we define humanity? Or mouse-ity, for that matter? When we create chimeras, when we blend the essence of humans, human tissue or human DNA, with the essence of another creature, then how do we determine the rights to which the resulting creature is entitled?
Please follow me down the orange rabbit hole. I'd love to hear your thoughts.
It is our brain which makes is who we are, that gives us our understanding of our world, gives us our sense of right and wrong, gives us a personality with emphasis on “person”. And, so, I was given pause when I read the news today. Researchers have transplanted brain cells into the brain of mice, and found it made them more intelligent, more like a human.
researchers … implanted human cells called glial progenitor cells into the brains of newborn mice.So, we have a creature that is a mix of animal tissue and human tissue, whose brain contains human tissue and whose brain operates less like the animal and more like the human. We can transplant pig heart valves into a human, and we still call the result a human. Now, when we have transplanted human brain cells into a mouse, we are still calling it a mouse.
…By the time the mice were 6 months old, the human cells had pushed out the mouse progenitor cells and replaced many of the mouse astrocytes with human astrocytes
…It took normal mice and mice with mouse cell transplants several tries to pick up on the association between the sound and the shock. Mice with human astrocytes “pretty much picked up the association immediately and got more fearful,” Goldman says.
It raises troubling questions. How much human brain tissue must be in a creature, how much like a person’s brain must a creature’s brain be, in order for the creature to gain “person” status, and be granted the inalienable rights with which all persons are endowed? Is it the form of a human that qualifies a creature for personhood? Is it the possession of a brain which is composed all or in part from human brain tissue? If so, then how much brain tissue or brain function is required to qualify for personhood? Or, is it the extent to which the creature can think and feel in the manner that is associated with humans? Is it "all of the above"?
These mice, with functional human brain tissue, brains which perform better than mice and more like humans, are experimental animals with relatively no legal protection. According to the research, they "...pretty much picked up the association immediately and got more fearful...”. I'd get more fearful, too, if realized I was being shocked on cue.
Theoretically, one could use a similar process to implant human brain tissue in a different type of animal, a larger animal which has dexterous hands like a raccoon or a chimpanzee, thus improving their intelligence and creating a race of slaves, with near or total human understanding and experience, and animal bodies which have no human rights. It is an extreme vision of a possible future, not likely in the near term (the changes were not germ level and would not be passed down through reproduction) but seemingly becoming more of a possibility every day.
I am particularly interested in brain research. I have hopes that research into how the brain functions might someday provide an answer for my own disabled child. I understand the need for research involving animals, or fetal stem cells, etc, and how much human suffering can be alleviated by the products of such research.
Still, when, as a result of our research, we blend so much of the human and the animal, I wonder about the suffering of the creature, and whether it can, at some point, be termed "human" suffering. At what point, does the extent of the human portion of that creature becomes sufficient to claim human rights?
What do you think?