Friday, February 24, 2012

The Hodgkin and Huxley Macarena

Last week, Oakland University had the honor of hosting James Keener, Distinguished Professor of Mathematics at the University of Utah. He gave a delightful talk as part of our Quantitative Biology lecture series. His book Mathematical Physiology won the 1998 Association of American Publishers award for the Best New Title in Mathematics. Somehow, Russ Hobbie and I failed to cite this book in the 4th edition of Intermediate Physics for Medicine and Biology. We did, however, cite Keener’s work with Sasha Panfilov on the three-dimensional propagation of electrical activity in the heart. You can learn more about Keener's career and research in a Society of Mathematical Biology newsletter.

One of my favorite features of Keener’s website is his instructions on how to do the Hodgkin-Huxley Macarena. A photograph shows a large group of researchers doing this dance at the Cold Spring Harbor Laboratory last summer. To make sense of the H&H Macarena, image that the left arm is the sodium channel “m” gate, and the right arm is the “h” gate, as discussed in chapter 6 of Intermediate Physics for Medicine and Biology. (Note: I assume the picture on Keener's website shows a person facing us, so that her left arm is on my right side). Initially h is open (right arm vertical) and m is closed (left arm horizontal). During an action potential, m opens (step 2 and 3) and then h closes (step 4 and 5) and the "nerve" becomes refractory. Since the h gate is slower than the m gate, perhaps you should imagine having a lead weight wrapped around your right wrist as you do the H&H Macarena. Unfortunately, Keener does not yet have a video posted (with music), but perhaps we can encourage him to make one. If readers of Introductory Physics for Medicine and Biology know only one dance, it should be the Hodgkin-Huxley Macarena (although the ECG dance is a close second).

No comments:

Post a Comment