I am interested in the device approach to biology that views biological systems as a system of devices, each with inputs and outputs using power supplies to implement an input-output relation that is well defined and reasonably robust. The device approach to biology is very similar to the approach that engineers take to a technological system that they have been asked to identify and control.
The device approach
The device approach was used by the English school of physiology before the word engineering was commonly used and is a most productive way to initiate investigation of biological systems, no matter how complex. The device approach emphasizes the goal. The goal is to understand enough detail to establish and control the device equation, but no more.
Experiments (from macroscopic measurements of function to atomic scale measurements of structure) are focused on the goal. Preparations are chosen so they make it easy to discover the input-output relation and to learn to control it. Much of the progress of biology arises from the judicious and productive choice of preparations, whether microbial genetics, squid nerve fibers or the retina of the eye.
The device approach emphasizes the types of models that are most useful in dealing with biology and biological experiments: they must have well-defined inputs and outputs, which necessarily occur at different places; thus, spatially uniform models are inherently awkward, to say the least. The device approach emphasizes the need for power to maintain a well-defined, reasonably robust input-output relation. Models at equilibrium where no power is available are limited in their utility.
Personal history
I have been interested in how physical things work as long as I can remember, and in how living things work nearly as long. It began from the day my father (a physician and then psychiatrist) showed me that was the best way to mold my interests to his approval.
At Harvard, John Edsall was my tutor. He did, in fact, tutor me, biweekly at first and then (nearly) weekly, nominally in biology, but really in the wisdom of science. John Edsall was the son of a Dean of Harvard Medical School, and was a fulcrum for the pivotal change from macroscopic to molecular biology at Harvard and elsewhere. He trained Bruce Alberts, David Eisenberg and Jared Diamond, among many other distinguished scientists.
My coursework was in physics, chemistry, applied mathematics and electrical engineering but, if my memory serves me correctly, not in biology. (I actually love evolutionary and descriptive biology as I love collecting classical CDs but those loves are hobbies more than anything else.) My undergraduate thesis solved the cable equation of physiology (i.e., the transmission line equations of engineering) with a Green’s function, reproducing in an elegant but useless way what I had learned from Morse and Feshbach about heat equations.
I completed my graduate work, which was experimental, at University College London, where my department chairperson, Bernard Katz, was to win the Nobel Prize a few years later. Fortunately, the chairperson of physiology, Andrew Huxley — who also won the Nobel Prize with Alan Hodgkin in 1964 — had solved the cable equations the way I had. But he had done so much earlier and much more originally and insightfully than me. Huxley was happy to spend many hours teaching me, on the side, as if he didn’t have enough else to do. My experimental work measured the spread of current in crab muscle fibers over a range of frequencies, using impedance spectroscopy, as it is now named rather pretentiously.
My many decades of experimental work focused on analyzing the flow of current in muscle fibers and then the lens of the eye.
I became a department chairperson at Rush Medical College in Chicago in 1976: The temptation of an endowed chair was enough to make a 34-year-old move from the perpetual spring of Brentwood (Los Angeles) to the recurrent vagaries of Midwestern weather. In the 1980s, I started thinking about the theoretical problem of describing ion movement through the water-filled tunnels of charge, or what we call ionic channels.
The ionic channel is where we still are. But gazing through this narrow hole has proven to be rather like looking through a keyhole in a door. The closer you get to it, the further you can see, even glimpsing the horizon (of knowledge) occasionally, even seeing a star or two, when all else seems dark.
In this installment of the American Physiological Society (APS) Living History of Physiology series, Robert S. Eisenberg, PhD, discusses how he became interested in science, his most significant contributions to physiology and his most influential career mentors. He also offers advice to students starting out in science today. Dr. Eisenberg was interviewed by Martin Frank, PhD, at Rush Medical College in Chicago.
Scientific publications
Recent work
Catacuzzeno, L., L. Sforna, F. Franciolini, and R. Eisenberg (2020). Why are voltage gated Na channels faster than K channels?: one multi-scale hierarchical model. Preprint available on the bioRxiv as document bioRxiv:2020.2005.2011.088559 [PDF]
Eisenberg, Robert S. (2020). Electrodynamics Correlates Knock-on and Knock-off: Current is Spatially Uniform in Ion Channels.
Preprint on the physics arXiv at https://arxiv.org/abs/2002.09012v3 [PDF]
Eisenberg, Robert S. (2020). Maxwell Equations Without a Polarization Field, Using a Paradigm from Biophysics. DOI: 10.20944/preprints202008.0555.v2 Preprint available on the physics arXiv at https://arxiv.org/pdf/2009.07088.pdf [PDF]
Liu, Jinn Liang and Bob Eisenberg (2020). Molecular Mean-Field Theory of Ionic Solutions: a Poisson-Nernst-Planck-Bikerman Model. Entropy, 22, 550; doi:10.3390/e22050550 [PDF]. Preprint available on the physics arXiv at https://arxiv.org/pdf/2004.10300.pdf [PDF]
Wang, Yiwei; Liu, Chun; Liu, Pei; and Bob Eisenberg (2020). Field Theory of Reaction-Diffusion: Mass Action with an Energetic Variational Approach. Preprint available on the physics arXiv at https://arxiv.org/abs/2001.10149 [PDF]
Eisenberg, Robert S. (2019). Dielectric Dilemma. Available on the physics arXiv at https://arxiv.org/abs/1901.10805 [PDF]
Eisenberg, Robert S. (2019). Kirchhoff’s Law Can be Exact. Preprint available on the physics arXiv at https://arxiv.org/abs/1905.13574 [PDF]
Eisenberg, Robert S. (2019). Updating Maxwell with Electrons, Charge and More Realistic Polarization. Preprint available on the physics arXiv at https://arxiv.org/abs/1904.09695v7 [PDF]
Horng, Tzyy-Leng, Eisenberg, Robert S., Liu, Chun, Bezanilla, Francisco (2019). Continuum gating current models computed with consistent interactions. Biophysical Journal, 116, 270-282 [PDF] Posted in 2017 at https://arxiv.org as preprint arXiv:1707.02566. [PDF]
Zhu, Yi, Shixin Xu, R.S. Eisenberg, and Huaxiong Huang (2019). A Bidomain Model for Lens Microcirculation. Biophysical Journal, 116, 1171-1184 [PDF] https://doi.org/10.1016/j.bpj.2019.02.007. Preprint available on the physics arXiv at https://arxiv.org/abs/1810.04162 [PDF]
Eisenberg, Bob (2018). Asking Biological Questions of Physical Systems: the Device Approach to Emergent Properties. Journal of Molecular Liquids 270: 212 https://doi.org/10.1016/j.molliq.2018.01.088, [PDF]. Preprint available on arXiv as https://arxiv.org/abs/1801.05452 [PDF]
Eisenberg, Bob, Gold, Nathan, Song, Zilong, and Huaxiong Huang (2018). What current flows through a resistor? Available on arXiv as https://arxiv.org/abs/1805.04814 [PDF]
Gavish, Nir, Liu, Chun, and Robert Eisenberg (2018). Do Bi-Stable Steric Poisson-Nernst-Planck Models Describe Single Channel Gating? J. Phys. Chem. B 2018, 122, 5183−5192 (DOI: 10.1021/acs.jpcb.8b00854). [PDF] available on arXiv as https://arxiv.org/abs/1805.06851
Liu, Jinn-Liang, and Bob Eisenberg (2018). Poisson-Fermi Modeling of Ion Activities in Aqueous Single and Mixed Electrolyte Solutions at Variable Temperature. Journal of Chemical Physics 148: 054501, DOI: 10.1063/1.5021508. [PDF]
Available on arXiv in 2017 as https://arxiv.org/abs/1801.03470 [PDF]
Additional publications
A complete publication list with live links to almost all publications is contained in my curriculum vitae.
Publications for general reader
Eisenberg, B. (2008). Grappling With the Cosmic Questions. Letter to Editor. New York Times. May 15, p A30.
Eisenberg, R.S. (2007). Look at Biological Systems Through an Engineer’s Eyes. Nature. Vol 447, p. 376.
Eisenberg, Bob. (2010). CSO Deserves Immense Credit. Letter to the Editor, Chicago Tribune. June 4.
Eisenberg, Bob. (2014). Shouldn’t We Make Biochemistry an Exact Science? ASBMB Today. 13: 36-38.
Eisenberg, Bob (2006). The Value of Einstein’s Mistakes. Einstein Should Be Allowed his Mistakes … Physics Today. (Letter to the Editor) 59 (4) p.12.
Eisenberg, R. (2015). Single Ion Channels. In Discoveries in Modern Science: Exploration, Invention, Technology. J. Trefil, editor. Farmington Hills, Mich.: Macmillan Reference USA. 1006-1010
Eisenberg, Bob. (2013). Ionic Interactions Are Everywhere. Physiology. 28: 28-38.
Eisenberg, B. (2016). Mass Action and Conservation of Current. HJIC: Hungarian Journal of Industry and Chemistry.
Eisenberg, Bob. (2012). Living Devices. The Physiological Point of View.
Eisenberg, Bob. (2012). Life’s Solutions. Mathematical Challenge.
Eisenberg, Bob. (2012). A Leading Role for Mathematics in the Study of Ionic Solutions. SIAM News, Vol. 45, Number 9 (November), p. 12-11.
Eisenberg, Bob. (2012). Ions in Fluctuating Channels: Transistors Alive. Fluctuation and Noise Letters. 11: 76-96.
Eisenberg, R.S. (1996). Atomic Biology, Electrostatics and Ionic Channels. In New Developments and Theoretical Studies of Proteins. Ch. 5, p. 269-357, Edited by Ron ElberWorld. Philadelphia: Scientific.
Eisenberg, R.S. (1996b). Computing the Field in Proteins and Channels. J. Membrane Biol. 150: 1-25.
Eisenberg, R.S. (1990). Channels as Enzymes. J. Membrane Biology. 115, 1-12 (1990) PMID: 1692343
Eisenberg, R.S. (1983). Impedance Measurement of the Electrical Structure of Skeletal Muscle. In Handbook of Physiology, Section 10: Skeletal Muscle, Editor: L. Peachey, American Physiological Society, pp. 301-323
Peskoff, A. and Eisenberg, R.S. (1973). Interpretation of Some Microelectrode Measurements of Electrical Properties of Cells. Ann. Rev. Biophysics. and Bioeng. 2: 65-79.
Contact
Robert Eisenberg, PhD
Professor
Rush University
Department of Physiology & Biophysics
Jelke Building
1750 W. Harrison St., Room 1519
Chicago, IL 60612
Phone: (312) 942-6454
Email: bob_eisenberg@rush.edu