Every once in a while there is something cool and new in the press. Recently I found an item on a technology site about the use of light from light emitting diodes (LEDs) shining on the spine or peripheral nerves to block pain signals. The concept is that light shined on the nerves or spine can affect the activity of neurons.
The information that I have found so far on this subject is very limited. The field is know as optogenetics. Apparently, there are light sensitive proteins in neuronal tissue. By illuminating these proteins, their activity can be modified. The proteins may then affect the ability of a nerve to transmit signals, and of special interest was whether pain signals could be affected by light.
Pain and Light
The initial interest in this field was generated with work on the brain. Light could be directed on various areas of the brain after a portion of the skull was surgically removed. Once light was directed to various structures, related behaviors would change. Originally the work was done with animals, mostly mice. The work has not progressed beyond that level as of yet.
The initial problem was directing a light to a particular area. Light sources were bulky as well as power sources. Fiber optic developments have included extremely fine, skinny fibers that are now flexible. These can then be guided to precise locations to target specific nerve tissue. Doctors can use minute LEDs that are small, low power, and that can be adjusted for maximum effectiveness to impact changes on the proteins and nerve cells. The whole system now has shrunk in size such that the light souce, fiber array to the nerves, and the power is transferred to the light by radiofrequency.
The first prototype device has now been designed and is being tested on a trial basis with mice. The light source was tested in the epidural space and over the sciatic nerve. By activating the light they could induce behaviors that were associated with pain. This the first step in studying the use of light and its ability to affect nerves that transmit pain signals. The concept is fascinating in the fact it is using a totally different process unlike surgery or drugs to control nerves. What will be the future of this technique and how it can be used best is only a guess. Hopefully it will lead to another technique that can help manage pain with fewer consequences like some other treatment methods.