Special Ingredient
Allow me to introduce you to the most famous cell you’ve
never met. Traditionally, when we think of brain cells, we think of neurons --
up until today, I was blissfully unaware that there were even any other types of
cells up there. Glial cells are similar to neurons, but they are to neurons as
I am to my older sister -- overshadowed. A recent story
from NPR noted on the role of glial cells and the ethics of an experiment with
very interesting results.
When Steve Goldman, MD, PhD, a neuroscientist at the
University Rochester, teamed up with his wife, Maiken Nedergaard, MD, DMSc, to
run some tests on glial cells, the outcome led to some intriguing results. Certain
types of human glial cells, called astrocytes, where injected into the brains
of baby mice. According to the article, the cells grew with the mice and,
structurally, remained the same as human glial cells, but revealed a curious
side effect. As the mice grew up, they were “measurably” more intelligent.
The article went on to note that the experimental mice
proved better in standard maze testing, taking as few as two tries to come up
with the right route, compared to an average of four or five in the normal mice
-- and better at recognizing potential threats. The latter of which became a
factor for Robert Streiffer, PhD, a bioethicist from the University of
Wisconsin-Madison, as he posed a question about the mice. As “perception of
fear” of one of the criteria to be taken into consideration when it comes to
animal testing, is it still ethical to experiment on these mice given their mixed
nature and increased intelligence?
“Maybe bioethicists have been a little bit too cavalier
assuming that a mouse with some human brain cells in it is just your normal old
mouse,” he said. “Well, it’s not going to be human, but that doesn’t mean it’s
a normal old mouse either.”
While questions like these hadn’t been taken into
consideration at the start, the results of the experiment have forced them. As
the article asks, “will these human-animal hybrids eventually get close enough
to humanity that we would feel uncomfortable performing experiments on them?”
Despite the moral dilemma, these tests beg a number of different questions. As
genetic research becomes clearer, what role will glial cells play -- both in
the laboratory and in practice?