Do anesthetics act on a membrane critical point?

Do anesthetics act on a membrane critical point?
Benjamin Machta, Princeton University
Date and time: Thu, Mar 24, 2016 - 11:30am
Location: LGRT 1033
Category: Condensed Matter Seminar
Abstract:
Many small molecules induce general anesthesia in animals ranging from insects to mammals. Although their mechanism of action remains controversial, it is known that a compound’s efficacy as an anesthetic is strongly predicted by both its hydrophobicity and its potency in inhibiting certain ion channels. I will first report on recent experiments in which we have shown that the n-alcohol anesthetics take plasma membrane derived vesicles away from a biologically tuned, two dimensional (2D) liquid-liquid critical point in the Ising Universality class. I will then discuss our ongoing tests of the hypothesis that anesthetics exert at least some of their effects by interfering with native regulation by the nearly critical plasma membrane. I will discuss what proximity to criticality means for membrane bound ion channels, and I will show simulation results from the 2D Ising model that suggest that ion channels could indeed be strongly affected by our measured changes in critical temperatures. In addition I will discuss our recent results showing that several treatments that reverse behavioral measures of anesthesia also raise critical temperatures in vesicles.