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Contribution

Posted by Harrison Friedman on 2009-06-21

Another blog. Blogging was definitely not part of my expectations for research this summer, but oh well.

I can’t say that I have any concrete expectations for my summer research. Concrete expectations after all are almost always confounded by unexpected circumstances, especially in research, in which unexpected results and challenges seem to be the norm. In general, I hope that I can reasonably expect this summer to make some small but substantiated contribution to my lab and to the field (with considerable emphasis on small); this, I think, is the general purpose of any research, even research conducted during the course of a (painfully short) summer internship. Any contribution I could make to my lab is of course much smaller than the great benefits I not only expect, but already know, I’ll get from the internship in education and introduction to new techniques. Already the program has introduced me to a whole new world of systems neuroscience (before the internship I was almost exclusively interested in the molecular and genetic areas of the field) and a number of really cool techniques (two-photon microscopy is awesome).


HF
 

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3 comments so far

Posted by Reader on 2009-06-27
Me again. Just what is two-photon microscopy? Is that one photon for each eye?
Posted by Harrison Friedman on 2009-07-05
Reader (whoever you are)- HA! One photon for each eye would be a little rough. No, two-photon microscopy is based on the two photon effect-- some obscure phenomenon in quantum mechanics in which certain molecules, when hit simultaneously with two photons at a given wavelength, emit a single photon at a shorter/higher energy wavelength. Most common fluorescent microscopes are "single-photon;" samples are stained with fluorescent dye, which is excited with light at a certain high frequency and emits light at another frequency (on the quantum scale, 1 photon excites the molecule, 1 photon is emitted). This is fine, except that the frequencies of light that most dyes respond to are fairly high. These high light frequencies tend to scatter a lot in biological tissues, leading to somewhat poor image resolution and problems imaging deep in tissue samples, not to mention that tissue can die as a result of exposure to the light. This is no good for live imaging of cortical circuits. Which is where two photon comes in. The two-photon effect allows dyes to be excited at a low frequency (infrared), which doesn't scatter as much in tissue and doesn't kill cells. Light emitted from the dyes is at a high frequency, which we can then see. This all allows us to image live neurons at various depths in living cortex. Pretty cool stuff. Not a very clear or thorough explanation (sorry), but hope it helps!
Posted by Reader on 2009-07-06
Great explanation. The technique is not at all what I expected. It is definitely cool.