Comparison between low doses of TMT and cat odor exposure in anxiety- and fear-related behaviors in mice

Few comparisons were made between cat odor and synthetic fox odor (TMT) to study fear and anxiety in rodents. TMT is frequently used are at high concentration while the stimulus should be as possible closer to natural conditions. The aim of this work was to compare behavioral responses of mice exposed to cat odor and low doses of TMT (i.e. 10 μl of a solution containing 1%, 0.1% or 0.01% TMT). Behavioral parameters were recorded in elevated plus-maze and in open field. Results showed that 1% TMT and 0.1% TMT induced similar responses to cat odor, contrary to water and 0.01% TMT which failed to elicit fear or anxiety-related behaviors. Additionally, behavioral changes were more marked in EPM – e.g. time spent in open arms – than in open field – e.g. freezing. These findings are discussed in terms of a possible continuum of mild anxiety-like behaviors to strong fear-like behaviors linked to predator odor intensity.

► Behavioral responses to predator odor are strongly different from one work to another.
► Fear and anxiety related behaviors are often jointly considered.
► Low doses of TMT like cat odor induce anxiety rather than fear related behaviors.
► These findings suggest a fear/anxiety dissociation linked to predator odor concentration.