Physics Club: Ben Machta, Yale University, “Criticality and Dynamical Bifurcations in Cellular Sensing”

Event time: 
Monday, April 18, 2022 - 4:00pm to 5:00pm
Sloane Physics Laboratory (SPL), Room 59 See map
217 Prospect Street
New Haven, CT 06511
Event description: 

Critical points are special places in parameter space where macroscopic system behavior is particularly sensitive to small changes in molecular details. In this talk I will explore a mechanism through which cells could use a critical point or related bifurcation to sensitively amplify and integrate small signals. I will argue that this general scheme could be used to solve a ubiquitous problem; integrating information from many individual noisy molecular sensors. My talk will specifically focus on a recent interest of ours; the pit organ of certain snakes which forms a low resolution infrared image used for hunting prey. For this organ to be functional, individual neurons innervating the pit must be able to respond to local heating <1mk, at least 1000x more sensitive than the thermo-TRP ion channels which evidence suggests are the molecular receptors for heat. I will present our model for how this remarkable sensitivity can be achieved. In our model individual ion channels are electrically coupled. Simple feedback self-tunes the neurons they reside in to a bifurcation which separates a state with low electrical activity from one with high electrical activity. Near this bifurcation the electrical activity becomes a very sharp function of temperature. I will also put our model into the context of other biological systems across scales which may use mathematically similar - though not evolutionarily homologous – strategies to tackle related engineering problems.
Host: Simon Mochrie (
The Colloquium series of the Yale Physics Department is called the Physics Club. The name dates to the late 1890s, the era of J Willard Gibbs, who influenced the intellectual life at Yale through a number of “graduate clubs”. He was one of the founders of the Mathematics Club which originated in 1877; he served as its executive officer for ten years. The Physics Club first met on the evening of Oct. 31, 1899, with 13 in attendance. Ever since, Physics Club has met regularly through each academic year, though in a break with tradition, we do not meet on the evening of Halloween. (Reference: Suha Gürsey, The History of Physics at Yale 1701-1970 (c) 2000.)
Physics Club is a weekly colloquium of general interest to the Department of Physics, Applied Physics, Astronomy, and Mathematics. The series is aimed at graduate students, postdoctoral researchers, research staff and faculty. For more information, or to request a Zoom link to attend, please send an E-mail with your name and institutional affiliation to Stacey Bonet, Chair’s Assistant