Author: Lori Marino

I’m a neuroscientist and a new paper in the journal Cell has me worried. The paper details the creation of a human/pig chimera by implanting human pluripotent stem cells into a pig embryo.

While the paper describes very preliminary steps towards the development of human/ungulate chimeras, the goal of the research program is to generate pigs and cows with human organs. Since cows and pigs are similar in size to humans, these organs could then be harvested and transplanted into humans as well as used for research on human disease, development and evolution. The key organs targeted in this research are heart, liver, kidney, pancreas, lungs and brains. Pigs and cows would become, essentially, living containers for human organs.

Another expectation of this kind of research is that these chimeras will serve as improved models for testing drug treatments, as well as boosting the availability of tissue for research and providing an unlimited source of organs.

Pigs and cows would become, essentially, living containers for human organs.

This research is part of a larger trend toward increasingly invasive and manipulative practices, from the domestication of animals for food, thousands of years ago, to the current culture of genetically modifying animals of many kinds: monkeys who show symptoms of autism, transgenic mice with altered vocalizations so that they “stutter”, cows who produce “humanized” milk, and mice injected with human brain cells that cause them to learn faster than normal.

The possibilities have many researchers giddy with excitement. But they also raise serious ethical dilemmas regarding the moral status of these part-human animals. The chimera test subjects have to be human enough to serve as effective models for health research, but not so “substantively humanized” that they qualify for protection from this research altogether.

Certainly, we all want to alleviate human suffering. But the need does not dictate the solution. As we continue down the path of this unprecedented manipulation of sentient beings, we simultaneously limit funding for alternative solutions to our health problems, including prevention, consensual human trials, incentives for organ donation, microchip testing, and in vitro research. All too soon, when we look back on the path of chimeric research that we’ve chosen, we may not like what we see. But it will be too late.

A particular area of concern is the creation of chimeras with human brain cells. These organisms may be capable of self-awareness to the extent that they understand their identity and circumstances, which will produce unbearable suffering. Will we know when the phenomenology of such a being has crossed, what for almost all people would be, the generally-accepted line of decency and morality? If we cannot say with certainty that this will never happen, we need to stop right now before we find ourselves in a world where there is no line.

These concerns about chimeric research do not negate the already potent ethical issues associated with mainstream invasive animal research. Tens of millions of animals are sickened, injured, genetically manipulated and killed in biomedical labs every year. And a robust body of scientific literature has shown that other animals are more self-aware, emotionally and cognitively complex than we previously thought, leading to the inescapable conclusion that we have already crossed a number of moral lines. Chimeric research will only exacerbate the suffering of animals and move it into areas of unforeseen consequences for which we are totally unprepared.

Unless we confront these issues now, we will find that our unrestricted efforts to save our bodies from sickness came at an unwelcome cost: the loss of our souls.

On August 4, the National Institutes of Health (NIH) proposed changes to its guidelines governing the funding eligibility of research involving human-nonhuman chimeras. The term chimera, in this context, means nonhuman vertebrates into whom human stem cells or tissues have been introduced at an early stage of embryonic or fetal development. The policy change proposes to end a one-year moratorium on funding this kind of research.

The NIH argues that the changes to the guidelines will open up new research opportunities to address human disease and create a way to respond to the ongoing need for human organ transplants. For example, pigs would be implanted with human stem cells to create hearts, livers, pancreases and kidneys to then “harvest” and place in human beings. The pigs would become, essentially, living growth chambers for human organs. Moreover, human brain cells would be implanted in other animals, such as monkeys, pigs and sheep, in order to find ways to treat Parkinson’s and Huntington’s disease. As the research develops, the possibilities become endless – and so do the ethical problems. The pigs would become, essentially, living growth chambers for human organs.

This research is part of a larger trend of increasing invasiveness of other animals that started with the domestication of farmed animals thousands of years ago and now includes such creations as genetically modified monkeys who show symptoms of autism, transgenic mice who “stutter” (have altered vocalizations), herds of cows who produce “humanized” milk, and mice injected with human glial (brain) cells who, eerily, end up a bit smarter, i.e., learning faster than normal.

The fact that the NIH is particularly invested in encouraging research that impacts the brains of nonhuman animals is especially worrisome because it has the potential to alter the psychological makeup and experience of these animals. The NIH admits that they do not have a full understanding of how this would affect the phenomenology and wellbeing of these chimeric animals. If mice with human glial cells are any indication, there is every reason to be troubled.

The NIH proposal runs counter to the robust body of scientific literature showing that other animals are more self-aware, emotionally complex, and individual than we previously thought. It is difficult to square the present proposal with those findings in any comfortable way. Public consciousness about the experience and welfare of other animals is growing. As a result of this, we have seen the NIH bringing an end to biomedical research on chimpanzees, along with the work of the Nonhuman Rights Project to gain legal personhood status for chimpanzees and other great apes, the growing public opposition to using wild animals in entertainment, and a growing rejection of diets based on factory-farmed animals.

I understand the desire to end human suffering and disease. Like everyone else, I watch family members and friends deal with conditions that rob them of quality of life and, sometimes, life itself.

However, the need does not dictate the solution. If we continue down this invasive path, we run the risk of limiting serious funding for alternative solutions cialis 20mg to our health problems. These include prevention, consensual human trials, incentives for organ donation, microchip testing, and the many methods of in vitro research, all of which are highly impactful in many areas of biomedical research and disease management.

At some point we will need to confront the choices we are making and, as has been the case for other long-term incremental stochastic processes like climate change, there will come a point in the near future when we will ask: How did we get here?

If you wish to comment on the new NIH proposal, please do so here by Sept 6, 2016.