Transplanted Human Brain Cells Make Mice Smarter: Bioethicists Wring Hands


Too smart for your own good?

A team of tesearchers at the University of Rochester led by biologist Steven Goldman transplanted early stage versions of human brain cells that make up the white matter in our brains into neonatal mice. The human glial cells thrived.

As reports:

Human glia are far more complex than mouse glia, and they help form many, many more connections, called synapses, between neurons. The more synapses, the faster and better the brain works. Tests in lab dishes showed the mouse brains with human cells transmitted signals much more quickly than normal mouse brains.

"So here we have these brains where most of the glia are human. And we know that human glia are different from those of most of other species," Goldman says. "Have their cognitive abilities been enhanced?"

The answer is, yes. The Rochester researchers tested their human/murine chimeras and found that they learned more quickly to avoid electric shocks and how to escape a maze than do normal mice.

The point of the research is not to create super-pests that can more easily evade mouse traps or steal cheese, but to probe the sources of various human nervous system diseases.

Predictably, New York University bioethicist Arthur Caplan issues the preemptory bioethical call for more regulations:

"This experiment is the ethical equivalent of Superstorm Sandy," Caplan says. "It brings together a controversial source of stem cells—obtained from aborted fetuses to create human-animal chimeras which frighten many members of the public and Congress.  The utility of the work for understanding diseases and the development of therapies for them is enormous but it is vitally important that an agreed upon, transparent and enforced set of rules and review processes be instituted to govern further research using stem cells from humans in animal brains or vice versa."

Unfortunately, a number of states—Louisiana, Arizona, Oklahoma—have already transparently agreed to enforce bans on such scientific research.

The plain fact is that people chiefly learn from trial-and-error, not from precautionary wisdom dispensed from on high by bioethical sages sitting in their endowed academic chairs. To the extent that regulations are needed, they should generally be formulated and adopted in response to what researchers, the public, and policymakers learn from scientific investigations, not based on vague fears gendered by icky-sounding experiments.

In this case, human fetal brain cells were used, but future experiments might well use less controversial stem cell sources like induced pluripotent stem cells (iPS) fashioned from mature skin cells.

For background, see my columns, "Brownback's Chimerical Attempt to Curb Science," "Senators Brownback and Landrieu Want to Outlaw Centaurs and Minotaurs," and "Ohio Senate Votes to Ban Minotaurs."