Using light to remotely activate drugs could be the next big thing in treating pain, depression, epilepsy and other neurological disorders. Researchers at Washington University in St. Louis have demonstrated the technology in mice in research funded by the National Institute on Drug Abuse, the National Institute of Mental Health, the National Institute of Neurological Disorders and Stroke and the Common Fund of the National Institutes of Health. Their work on optogenetics, a technology that makes individual brain cells sensitive to light and then activates those targeted populations of cells with flashes of light, was published in Cell and reported by Jim Dryden in Futurity (http://feedly.com/i/subscription/feed/http://www.futurity.org/feed/).
According to an article in Scientific American, optogenetics combines genetics and optics to control well-defined events within specific cells of living tissue. It includes "the discovery and insertion into cells of genes that confer light responsiveness; the associated technologies for delivering light deep into organisms as complex as freely moving mammals, for targeting light-sensitivity to cells of interest, and for assessing specific readouts, or effects, of this optical control." Optogenetics has the potential for control over defined events within defined cell types at defined times, a level of precision that is most likely crucial to biological understanding even beyond neuroscience. It enables scientist to understand the significance of any event in a cell in the context of the other events occurring around it in the rest of the tissue, the whole organism or even the larger environment (http://www.scientificamerican.com/article.cfm?id=optogenetics-controlling).)
As explained by co-principal investigator Michael R. Bruchas, associate professor of anesthesiology and neurobiology at Washington University in St. Louis, "In the future, it should be possible to manufacture therapeutic drugs that could be activated with light. With one of these tiny devices implanted, we could theoretically deliver a drug to a specific brain region and activate that drug with light as needed. This approach potentially could deliver therapies that are much more targeted but have fewer side effects."
While prior attempts to deliver drugs or other substances to experimental animals have necessitated tethering the animals to pumps and tubes, the new devices have four chambers to carry drugs directly into the brain. In the process of activating brain cells with drugs and light, the scientists can see the inner workings of the brain.
John A. Rogers, the study's other co-principal investigator and professor of materials science and engineering at the University of Illinois, summarizes, "We've successfully produced and demonstrated an implantable, cellular-scale microfluidic and micro-optical interface to biology, with application opportunities not only in the brain but in other parts of the nervous system and other organs as well."
