Electrodes, translational work, and human subjects. There is said it…as far as I am concerned these are the things that are holding back the advancement of neuroscience. Don’t get me wrong, neuroscience is certainly moving forward but at a snail pace relative to the leaps and bounds seen in physics at the turn of the century, or in biologics in the past thirty years. As with most fields of study, neuroscience was helped greatly by advancements in physics, which made it possible to image some of the biomechanics of the neuron, but also by math and statistics which gave rise to computational neuroscience and many insights to how networks of neurons made “decisions” by classifying inputs, and biology as well, where the surferdude Kary Mullis’s discovery of the Polymerase Chain Reaction (PCR) has provided us with many avenues to more easily inspect the traits of brain cells.
Electrodes are used to record and to stimulate neurons in the brain. In essence they are artificial dendrites and axons. Here is the problem: every neuron has anywhere from a few hundred inbound synapses to tens of thousands (an order of magnitude more than that in some cells of the cerebellum). Each of those synapses is doing something different at any point in time. By stimulating the same cell with a single electrode we are imposing on the cell a non-distributed input of a single type and source. And for that matter, because the electrode is floating in the medium next to the cell, there are hundreds of thousands of nearby cells that are forced to receive the same non-specialized input. The most advanced electrodes are what are called Multi-Electrode Arrays (MEA’s) and have up to a few hundred individual electrodes. That is fine, but we are a long ways away from reaching the resolution of a natural neural input.
2. Translational Work
At first glance you might think I am talking about language barriers (also a problem but not as big as you might think); in this case, I am specifically referring to work to develop translational technologies that would make neuroscientific discoveries valuable to the mass market in the form of a product or service. You might wonder how this could help increase the pace of innovation in the field of neuroscience well money has a way of inspiring creativity…even if the influx of cash alone didnt inspire creativity among existing neuroscientists it would certainly help by attracting a new cadre of smart young contributors.
3. Human Subjects
Other disciplines have the convenience of developing what is called a model to help them study pathology. Interestingly, and unfortunately, many human brain pathologies are unique to us because of the crucial evolutionary characteristics of our brains. Specifically disorders of a cortical nature may have no real analog in other animals. Another serious limitation specific to brains is that many of the traits we wish to study are difficult to characterize without the subject being able to express their own experience through speech…being the only animals on the planet capable of advanced speech you can see how this could severely limit the access to test subjects. As a third dynamic (though one not specific to brain science), HIPAA (health information protection legislation) and the FDA (Food and Drug Administration) put stringent controls on who, how, when, and under what conditions tests can be performed. These factors add up to make securing human subjects for neurological studies incredibly difficult.
So with all of the progress we have made why is it that I chose to latch onto these three problems in particular? It is interesting to notice that only one of them is technical in nature…You might think that one or more of these problems is easy and should be simple to solve. Between human ethical considerations and even more human creative limitations we are forced to inch our way along as always; breakthroughs are, more often than not, the result to many years of very hard work instead of simple genius or a stroke of good luck.
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Clayton S. Bingham is a Biomedical Engineer working at the Center for Neural Engineering at University of Souther California. Under the direction of Drs. Theodore Berger and Dong Song, Clayton builds large-scale computational models of neurological systems. Currently, the emphasis is on the modeling of Hippocampal tissue in response to electrical stimulation with the goal of optimizing the placement of stimulating electrodes in regions of the brain that are dysfunctional. These therapies can be used for a broad range of pathologies including Alzheimer’s, various motor disorders, depression, and Epilepsy.
If you have any interest in writing here or would like to hear more about the work done by Clayton in the USC Center for Neural Engineering he can be reached at: clayton dot bingham at gmail dot com.