In search of attractors in living cells
In dynamical systems, an attractor is a set of states toward which a system tends to evolve. 99% of the current biological literature describes cellular states which can be classified as “point attractor”, where the system will eventually return to the same steady state after certain perturbation. In contrast, periodic patterns have been widely observed in multicellular systems such as cardiac tissue and slime molds. More recently, oscillatory waves of cortical activity, linked to actin dynamics in many cases, have been documented in a variety of single-cell systems. These works concern a second type of dynamical states, namely “limit cycle attractor”, where all trajectories tend to be trapped in a close loop in phase space. I will describe our work in characterizing cortical oscillations in mast cell, a type of immune cells important for innate immunity. In addition to limit cycle attractor, I will discuss the possible existence of a third type of attractor in cortical state, i.e. “strange attractor”, or commonly known as chaos. Collectively, identification and direct visualization of these attractor states offer unprecedented opportunities to think about the organization and dynamics of living systems, where non-linear networks and paradoxical circuits are prevalent, using the dynamical systems framework.
Hosted by Professor Zheng Shi
~Coffee/tea will be served prior to the lecture~