Predator Odor-induced Freezing Test for Mice.

The innate fear response is an emotional response that does not require any previously acquired conditioning. One of the standard methods to analyze the innate fear response is a 2,4,5-trimethylthiazoline (TMT)-induced freezing test. TMT is an odor originally isolated from anal secretion of the red fox. Acute TMT exposure has been shown to induce robust freezing behavior in rats and mice (Wallace and Rosen, 2000; Galliot et al., 2012 ). Here, I show how to expose mice to TMT and how to analyze their freezing behavior.