Advancements in Cortical Recordings through Nanoscale Sensors

The advent of MRI brought us into a world of intense study and remarkable spatial resolution of virtually all brain functions. The only problem is the temporal resolution that you get with fMRI recordings. Since the magnet has to scan the brain, its temporal spacing is quite distant, so to diagnose the timing and active area concerning certain functions, neuroscientists have been limited to MEG recordings and patients who require invasive brain surgery which can be used to set up electrodes deep within fissures. A collaborative effort however has managed to engineer an extremely thin, flexible film of silicon upon which a multitude of transistors are placed and interconnected (720 to be exact). What makes this device unique lies in its flexibility which allows it to be spread in between sulci or fissures without causing inflammation or tissue damage which is a common issue with the current bulky electrodes. The researchers have been able to connect these 720 transistors into 360 arrays with each row receiving the same input. With this large number of transistors, and reduction in wiring a larger surface area may be monitored with great spatial resolution. The big picture behind this product is to be able to efficiently record brain activity in deeper cortical regions, as well as monitor abnormal electrical activity which may correspond to epileptic seizures. With the hope that one day they could be manipulated to stimulate brain activity and be used in neuroprostheses to revitalize connections that may have been lost due to strokes, etc. The exciting discovery that the research team made was the recording of spiral waves in the brain. I am not going to dive into spiral waves since I am not familiar with them either, but the basics are that these waves propagate abnormally exciting the heart, and are thought to be the underlying cause of cardiac arrhythmia. If it turns out that these spiral waves are connected to epileptic seizures then medical science may be able to suppress seizures in a similar fashion that they inhibit heart arrhythmias. Personally, I am more excited about the potential these thin films offer people who have lost control of limbs or who have lesions localized to certain fasciculus. With the way modern electronics has moved towards nanoscale fabrication it would not be surprising to observe neural networking through semiconducting materials. The complex version of the article can be found on Nature Neuroscience, http://www.nature.com/neuro/journal/vaop/ncurrent/abs/nn.2973.html. And the simpler "I’m not a physics major" friendly version here - http://www.sciencedaily.com/releases/2011/11/111113141405.htm.