Whisker nuisance test: a valuable tool to assess tactile hypersensitivity in mice

Abnormal response to tactile stimulation, described as both hyper- and hypo-reactivity, is a common sensory impairment in multiple neuropsychiatric disorders. The neural bases of tactile sensitivity remain so far unknown. In the last years, animal studies have proven to be useful for shedding light on the cellular and molecular mechanism underlying sensory impairments. However, few behavioral tests have been developed in mice for assessing tactile perception abnormalities (e.g., the whisker nuisance [WN] test and the tactile prepulse inhibition assay). Here we provide a modified version of the WN test, which is based on the previously developed method by McNamara et al. (2010). The WN test permits to specifically detect tactile hypo/hyper-sensitivity relative to whisker stimulation in mice. The test starts with a habituation phase in which the mouse familiarizes itself with the experimental cage and the researcher/experimenter. After a sham session, the experimental session begins, consisting of bilateral whisker stimulation with a wooden stick. The advantages of using this protocol are many: it is relatively simple to set with no particular or expensive equipment needed, it is easily reproducible, it allows researchers to assess a variety of behavioral responses to a whisker-specific tactile perception in mice (i.e., fearful behavior, stance, hyperventilation, aggressive behavior and evasiveness) and provides important translational opportunities.