Mice with human glial cells are smarter | Hacker News Reader

Mice with human glial cells are smarter

newscientist.com

48 pointslettergram13 comments

The glial-neuron relationship is an interesting one, and far from fully understood at this time. New things turn up on a regular basis, such as this fascinating insight regarding cooperative mitochondrial disposal:

http://www.the-scientist.com/?articles.view/articleNo/41275/...

Glial cells may turn out to be a good source of new neurons. Since they are generated at a fairly fast past, one approach to increasing neural plasticity is to reprogram glia into neurons rather than try to boost neurogenesis directly. This is just one of several groups I've seen of late working on that:

http://www.sciencedaily.com/releases/2014/11/141120123136.ht...

I also find it interesting. Specially in history. In his book: "The Root of Thought" (http://www.scientificamerican.com/article/the-root-of-though...) Dr. Andrew Koob, talks about the importance of Glial cells and the possibility of it being responsible for consciousness.

I think with the new technological innovations in the field of Neuroscience we might get a better understanding of what these cells actually do in the human brain, other than "glue" things together.

Based on the paper's abstract, they look at both wild mice and "shiverer" mutant mice, which have a lot of neural problems (see this: http://jaxmice.jax.org/strain/001428.html ). I can't access the paper from here, but I wonder if the intelligence results in the New Scientist article are just about the shiverer mice. Here is the abstract:

Neonatally transplanted human glial progenitor cells (hGPCs) densely engraft and myelinate the hypomyelinated shiverer mouse. We found that, in hGPC-xenografted mice, the human donor cells continue to expand throughout the forebrain, systematically replacing the host murine glia. The differentiation of the donor cells is influenced by the host environment, such that more donor cells differentiated as oligodendrocytes in the hypomyelinated shiverer brain than in myelin wild-types, in which hGPCs were more likely to remain as progenitors. Yet in each recipient, both the number and relative proportion of mouse GPCs fell as a function of time, concomitant with the mitotic expansion and spread of donor hGPCs. By a year after neonatal xenograft, the forebrain GPC populations of implanted mice were largely, and often entirely, of human origin. Thus, neonatally implanted hGPCs outcompeted and ultimately replaced the host population of mouse GPCs, ultimately generating mice with a humanized glial progenitor population. These human glial chimeric mice should permit us to define the specific contributions of glia to a broad variety of neurological disorders, using human cells in vivo.

Are there any animal species with higher glial cell efficiency than we humans have?

Elephants, I believe

> > Are there any animal species with higher glial cell efficiency than we humans have?

> Elephants, I believe

I tried to find some info on this then realized I wasn't sure what GP meant by "glial cell efficiency." I did find a claim that "the human brain has about 90%; and the elephant brain consists of some 97% glia." [1]

Is the percentage of glial cells what you mean by "glial cell efficiency"?

[1] http://www.nature.com/nature/journal/v457/n7230/full/457675a...

I guess what I was getting at is, it would be very interesting if there was an animal whose glial cels had similar effects when injected into developing human brains as our cels had on the mouse brains in the article.

We the human race need to get past some of our squeamishness. These precursors to glial cells absolutely need to be injected into chimps. We need to understand what happens. Real lives are at stake, and real quality of life for real people is at stake.

Caution and ethics are a good thing, and I'm glad we're not ignoring them like barbarians. But we are too cautious at times, as if we don't fully acknowledge the truth that real people are dying who could benefit.

>In one test that measures ability to remember a sound associated with a mild electric shock, for example, the humanised mice froze for four times as long as other mice when they heard the sound

If that's their best example of raised intelligence it's not that impressive. It could just be that the humanised mice stayed scared longer. Something like learning a maze quicker would be much more convincing.

And their conclusion was that "if these mouse stayed frozen for 4 times longer, that means their memory was at least 4 times better". Isn't that a bit strange assumption? If both mice froze, means both remembered it. How can one mouse memory be better just because it acted differently after recalling something?

This poses some interesting questions. Brushing away a lot of (critical) detail...

- What is the range of efficiency across the glial cells of different humans?

- Assuming meaningful variance, can we perhaps transplant "better" glial cells to humans with "lesser" glial cells?

We are going to need to build an even better mousetrap.

The big question, what else changes?

Perhaps humans with mouse glial cells would be happier.

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