 A molecular explanation for the difference between flurothyl and iso-flurothyl was provided by electrophysiology studies that showed flurothyl was an antagonist (blocker) of neuronal GABAA receptors and had no effect on neuronal glycine receptors.This receptor selectivity resembles that of the well-characterized GABAA receptor antagonist picrotoxin.Studies using recombinant GABAA and glycine receptors confirmed this activity profile and further showed that iso-flurothyl behaved similar to other ether anesthetics in acting as a positive allosteric modulator of GABAA and glycine receptors.