Mapping neurons without glial cells ~ SNP genotyping w/o whole sequencing?

Nature’s Journal Club column is usually a good & always a short read providing exciting angles on scientific topics/papers from good researchers. Recently ‘neuroscientist’ Dave Featherstone argued for a broader approach to brain mapping by not restricting it only to the connectome between neurons. Neurons are making up less than 10% of the human brain while most brains cells are glia neglected by scientists making the wiring diagram of a ‘complete’ human brain.

For example, consider the recent study of adenosine and sleep led by Philip Haydon and Marcos Frank at the University of Pennsylvania in Philadelphia (M. M. Halassa et al. Neuron 61, 213–219; 2009). Adenosine binds to receptors on neurons, thereby regulating neuronal signalling. Interestingly, adenosine seems to represent ‘sleepiness’: it accumulates during wakefulness and dissipates during sleep. Where does it come from? It is generated from adenosine triphosphate (ATP), which is secreted by astrocytes — a major type of glia.
Therefore, if we want to map the functional brain connections controlling sleep, we need to include glia and the extracellular space between glia and neurons. If we’re going to understand brain function by mapping the brain, we need to include most of the brain in our map.

I tried to draw an analogy between the situation in brain mapping and personal genomics on FriendFeed:


Update: it seems Dave Featherstone had something similar in mind as an analogy, he answered my email the following way:

Yeah, that’s a good analogy. The original version of my column said the connectome would be like if the human genome had only sequenced exons. But that sentence was cut for space considerations.

Nature Insight: The complex trait of quantitative genetics

Nature’s newest issue has a Quantitative genetics supplement with 3 free access pieces included out which I find this review the most interesting: Reverse engineering the genotype–phenotype map with natural genetic variation by Matthew V. Rockman. There’s a lot information to digest and many patterns to understand in this background field in order to approach the future of (personal) genetics/genomics.


Nature Personal Genomics Very Special

The newest Nature issue concentrates on personal genomics and its consequences via many types of articles some of them with free access.

I only read 1 piece so far by Erika Check Hayden, who has the exclusive freedom at Nature to always pick the best stories and write on any of them, but being a heavy 23andMe user I was instantly reminded again on the program Promethease with which I can extend the interpretation of my data with an approximately 2 hour run.

According to two commercial gene-testing services — 23andMe and deCODEme — US Army medic Timothy Richard Gall of Fort Belvoir, Virginia, has a higher-than-average risk of basal cell carcinoma, type 2 diabetes and psoriasis. But much more enlightening than these results, which cost Gall more than $1,400, was a free online program called Promethease that he used to further analyse the data. By offering more in-depth information and interpreting of more of his genetic variants, Promethease “gives a much more realistic view of the usefulness of the information”, Gall says. Start-ups and services such as Promethease are now developing ways to improve the limited value of information provided by personal genomics companies for consumers and scientists alike.


“ v1 is live” and beyond

A new, completely rewritten, integrated website has been launched by the Natureplex people – informed his Twitter pals Euan Adie:

Also, v1 is live! Tequila and donuts all round. Early n’ often release v2 coming on the 18th so get any bug reports in now.


Suggest good science blogs that are not listed on the Nature Blogroll yet.

Compare scientific websites with a new Google Trends layer!

I always had the feeling that the Natureplex (the web division of the Nature Publishing Group headed by Timo Hannay) is ahead of most scientific journal publishing conglomerate’s similar departments. Now with the help of a new Google Trends layer that compares websites in terms of traffic this impression was confirmed again without strict numbers. I hope that more and more scientific journals gain incentives finally to experiment with new web technologies. Also a quick look to the Regions comparison on the bottom left helps you give up the history based conclusion that Science is the number 1 on the web in the US compared to Nature while Nature is so UK and Europe centric.

“Today, we add a new layer to Trends with Google Trends for Websites, a fun tool that gives you a view of how popular your favorite websites are, including your own! It also compares and ranks site visitation across geographies, and related websites and searches”

Source: Official Google Webmaster Central Blog via Webmonkey

The same comparison with Alexa: Continue reading

What path would you follow: Shumway or Barnard?

Monya Baker has an excellent Q&A with the authors of the recent Nature Insight: Regenerative Medicine over at The Niche blog. Ken Chien, the author of Regenerative medicine and human models of human disease – see earlier postrecalls the paradigmatic story of heart transplantation and the 2 main surgeons behind, Norman Shumway and Christiaan Barnard, who are perfect representatives of the different paths of pioneering clinicians:

Sometimes in looking forward it’s good to look back. In cardiac regenerative medicine, probably the only clear success to date is heart transplantation. From the initial grant that Norman Shumway received in 1958 [to study the possibility of heart transplantation] it took more than two decades before the procedure became routine.

Shumway was a careful, thoughtful man. He not only didn’t do the first heart transplant; he didn’t do the second. He was slowed down in the United States because of the regulatory barriers and ethical concerns. Christiaan Barnard, on the other hand, went back to South Africa and decided to just go for it. Sounds familiar?

We realized very quickly that this was not working, that the science was not there. In 1968, a year after his first attempt, Barnard gave up on the procedure and considered it a failure. Everyone gave up, except Shumway. He went back to the lab and spent the next ten years figuring it out. He realized that the issue was rejection. Continue reading