Friday, July 17, 2009

Synesthesia: the neurological disorder you wish you had

Lately I’ve been thinking1 about synethesia. Synethesia is a neurological condition in which there is a mix-up between the senses, whereby the person will experience things described as “tasting colour” or “feeling sound” (i.e. when they experience a taste, a colourful aura specific to the taste will appear in front of their eyes).  I’ve included a couple videos here which give an idea what this condition is like. The first video is a snappy overview of what synethesia is all about. Personally I think the condition is exemplified best at the end of the clip when it shows a guy eating chicken with vanilla ice cream and orange sauce on it with a big smile on his face as a whole bunch of blue colours come up in front of his eyes.  The second video is a TED talk from superstar neurologist VS Ramachandran talking about a whole bunch of things which are all very cool, but he starts talking about synethesia around 17:45, if you only want to hear about that. He brings up a cool point right near the end about how we all have synethesia to a certain extent. Please enjoy:

Synethesia is one of things which makes neuroscience really interesting to me, because it leads to so many questions. Questions such as, if these people can live essentially normal lives with the condition, what is the evolutionary advantage to not having synethesia? Is it really only a result of a faulty gene, or a couple of faulty genes, and if so, could we engineer synethesia genes and demonstrate them in an animal model? Is it something that we all have lying dormant in our brains, and can we somehow “tap in” to it? And lastly, why not me? 

Dr. Richard Cytowic (the author of the book that I got) argues that synethesia is actually a normal brain function that we all have, but only a small percentage of people are actually conscious of it. He gives a few examples where “normal” people can/may experience synethesia-like effects, including deep meditation, LSD induced hallucinations and also he mentions a case where a guy had a tumor of the left medial temporal lobe, who would see colours when hearing certain frequencies. Upon removing the tumor he could no longer experience any sort of synethetic effects.

So if synethesia is potentially lingering in all of our brains, can we train ourselves to become synethetic? Beats me. But I did have an idea to test it out. I think it would be interesting to create a keyboard with a big screen right in front of it, which would display auras of colours on it, each colour representing a different note. For example, E could be yellow, and an E major chord could be predominantly yellow with the other colours for G# and B subtlety mixed in.  If you were to start from childhood and learn to play the piano like this, I wonder if the association of colour and sound would become cemented in the brain, and whether or not this association would be transferred to listening to music on a CD or in a concert or even just ambient noise?

Synethesia is an interesting case of what the human brain can be capable of, and one of the many cases where I wonder why the mass of neurons in my head can’t do it, while the neurons in someone else’s head can. Perhaps someday we will have a better understanding of how the brain works, and how synethetic experiences arise. Until then however, the rest of us will just have to stick to LSD.


1 and by thinking I mean I got a book out of the library about synethesia and put it on my desk.

Saturday, July 4, 2009

Viruses and Life

Recently it has come to my attention that viruses are really cool.

In terms of biomass (and numbers for that matter), they are by far a much more abundant organism on the earth then humans. They can infect essentially every living species from bacteria to plants to mammals, and can, in some cases, be notoriously hard to beat. In the oceans, viruses play important roles in geochemical cycles and carbon turnover. They kill approximately 20% of all microbial biomass every day, which has a major impact on nutrient and energy cycles.

This new found interest in viruses also is a result of the current projects I am working on. Viruses work by floating around in your system until they find a cell in your body that they are capable of latching on to. Once they`ve done this, they inject their DNA into the cell, and basically ``hijack`` the cell and use it to create more viruses. We can exploit this system in the lab. By taking out the genes in the virus that cause the cell to create new virus particles, and replacing them with genes who`s products we are interested in, we can use the virus as an efficient delivery system to insert new genes into cells. In my case, I have a plate of cells which I bombard with literally millions of virus particles. The virus particles will then dock on the cells (mouse embryonic cells in the case) and insert the gene for Cre recombinase , which will then act to cut out a different gene out of tGFP cellshe cell genome... though that part is a different story. You can just as easily have the virus inject green fluorescent  protein, which will cause the cells to glow a neon green in certain light.

Despite all this, there is still an ongoing debate as to whether or not viruses can be considered “alive”. I recently just read an article entitled “Ten reasons to exclude viruses from the tree of life” (Moreira, D. et al. Nat. Rev. Microbiol 7, 306-311 (2009).) which, as you can probably deduce, argued the negative. The main idea that this article was getting at was that essentially viruses can not reproduce, evolve or pretty much even survive unless it makes use of another cell.  They go as far as to say that if you were to take all of the world’s viruses and dump them onto a new, sterile planet, eventually they would all eventually die and decay. In contrast, they argue, if you were to do the same with all the different bacteria species on the Earth, it is likely that at least some of them would thrive.  The authors bring up a number of other points as well, such as the fact that it is impossible to trace a virus lineage back to a common ancestor (i.e. not a single gene is shared between all viruses) and that viruses only “steal” genes from cells, and do not develop them on their own.

While I can agree with most of the points that the authors make, I still feel unsatisfied accepting the view that viruses are not alive, and I think (for me at least) what it comes down to is the operational definition of life that is being used. This definition, which we all learned in grade 9 science class, basically sets down a check list of things that you need to be considered alive such as the ability to produce energy, waste, the ability to reproduce and adapt to surroundings… etc. This definition though, seems almost too stringent. To me, a much more fitting (though perhaps a too broad) definition would be this: life is the ability of a bit matter to actively work to persist its information throughout time. For example, how is it that the atoms that make up a virus “know” to seek out similar atoms and organize them into a similar form as itself before they fall apart? Where did this intrinsic “desire” to pass on this information come from? What makes some particular organization of matter more able to pass on this information while other random organizations just float around? To me this idea represents the very essence of what it means to be alive. You can even think of it on a larger scale. When we die, we lose the ability to maintain our organization of matter, and we decompose. During the time we are alive though, we take in atoms and molecules from our food and the air, and use those molecules as building blocks for our cells. When I think about it, it is a sobering thought. What would the world be like today if matter could not organize itself into reproducible forms? Probably pretty boring, I’d wager.