14 DAY TRIAL // A collaboration of investigators from the Harvard University and the Massachusetts Institute of Technology (MIT) say that specific waves of electrical activity develop in the human brain according to the different states the brain is in at any given time.
By analyzing these wave patterns, investigators say that it may be possible to gain some new insight into how the brain behaves during comatose or other quiescent states. A model of neuro-electric activity could come in very handy to medical investigators in the near future.
Thus far, scientists have identified the large-scale patterns the brain displays when it is alert, relaxed or asleep. These data are clearly visible on electroencephalogram (EEG) scans, and can be studied primarily because scientists have numerous points of reference.
What is interesting to discover is how these patterns change when the brain enters less-common states, such as for example those recorded during general anesthesia and comas. The reason why the changes occur is also of great interest to researchers.
During the new investigation, the MIT/Harvard group was able to figure out how a neural state called burst suppression occurs. When this state occurs, the brain literally goes into sleep mode, since EEG scanners cannot detect any activity for up to several seconds.
This interval is dotted by very brief bursts of neural activity. The state can be seen in patients whose comas were inducted by doctors to control seizures, and in people who just suffered from heart attacks.
Details of the new investigation were published in the February 6 issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS). The study was led by expert Emery Brown.
He holds an appointment as an anesthesiologist at the Massachusetts General Hospital, and is also a professor of brain and cognitive sciences, and health sciences and technology, at MIT. His interest was discovering the fundamental mechanism through which burst suppression patterns arises.
“You might be able to develop a much more principled way to guide therapy for using burst suppression in cases of medical coma. The question is, how do you know that patients are sufficiently brain-protected? Should they have one burst every second? Or one every five seconds?” he asks.
The research group was able to create a new model of how burst suppression arises. The simulation was based on describing how channels controlling the flow of potassium and sodium ions in each neuron function together.
Brown Lab postdoctoral researcher ShiNung Ching compiled the model, which uses math to model the neural flow of ions in individual neurons. By simulating multiple nerve cells at the same time, he managed to create a model of the large-scale behavior of the brain.