The neural pathways that is… I’ll explain in a moment.
But first, lets think back to 1991 when scientists from the NIND (National Institute of Neurological Disorders) invented a brand new way of measuring the chemical changes happening within the brains neurotransmitters. Using a tiny, ultra-sensitive electrode they could measure the release of catecholamine’s (A type of hormone) produced by the neurons to observe how specific drugs would affect the release of the hormone (NIND, 1991). While at the time this was seen to be a revolutionary view and a huge advancement in the testing of drugs, it had its draw backs. These electrodes needed to be attached to the neurons in order to measure their output and doing so would kill off the cells rather quickly. This method also only allowed for a single reading, failing to create a spatial map of how the signals would propagate (Harvard University, 2011).
Now let me explain where light comes into this. If you have watched an underwater animal documentary on television then you may have noticed several species of fish and the like which let off a fluorescent glow, deep below the surface water. These animals perform this amazing function by using a protein (Either GFP (Green Fluorescent Protein) or aequorin) and would normally use it as a form of camouflage (Mills, 1999). This protein has successfully been cloned and reproduced for several biochemical studies, but the most recent that we are going to look at is the research led by Loeb at Harvard University.
His research looks at using a gene involved in creating this protein that when exposed to an electrical charge will become fluorescent, allowing researchers to trace the propagation of signals through a brain cell. To achieve this, the protein must first be attached to a genetically modified virus and then attached to a cell; once infected the cell will then begin to create the protein by itself. Once complete the protein will glow in places which there is an electrical charge flowing through it, showing us not only which neurons are being activated, but the paths taken between them. Using this information we can also track changes in the pathways and the creation of new ones, creating a spatial map of operation (Harvard University, 2011).
This type of research will open up the doors to many possibilities, but for the moment the focus would seem to be on testing the efficiency of various drugs on a cell; where before this would have taken a while to observe, only being able to test one or ten compounds at a time, we are now able to test hundreds or even thousands at a time. This will even provide us with the ability to test the same drugs under different conditions and is expected to increase the throughput for the testing of new drugs. It is also expected the it will open up new possibilities in the research of heart disease and depression, as well as numerous other areas; particularly the ability to create genetically identical stem cells and study the difference in the neural pathways between a patient with a genetic predisposition to a particular condition.
Harvard University. (2011, 12 1). Neurons Created That Light Up As They Fire. Retrieved 12 02, 2011, from Medical News Today: http://www.medicalnewstoday.com/releases/238439.php
Mills, C. E. (1999, 01 11). Aquorea. Retrieved 12 02, 2011, from Washington University: http://faculty.washington.edu/cemills/Aequorea.html
NIND. (1991, 06 17). Newly developed electrode records neurotransmitter release from a single cell. Retrieved 02 12, 2011, from National institute of Neurological Disorders and Stroke: http://www.ninds.nih.gov/news_and_events/news_articles/pressrelease_electrode_061791.htm