Hair barbering in mice: implications for neurobehavioural research.

Barbering (fur/whisker trimming, the Dalila effect) is a behaviour-associated hair and whisker loss frequently seen in laboratory rodents, including mice. Here we analyse barbering behaviour in 129S1, NMRI, C57BL/6 and BALB/c mouse strains and some of their F1 hybrids. Our study shows that barbering in mice, depending on their genotype, is a complex behaviour with several distinct contexts or domains. We observed social (dominant) barbering in NMRI and C57BL/6 mice, sexual over-grooming in 129S1 and C57BL/6 mice, maternal barbering in lactating 129S1 and C57BL/6 mice, and stress-evoked barbering in F1 (NMRIx129S1) hybrids. In contrast, aggressive BALB/c mice and their F1 progeny do not use barbering in their behaviour. We suggest that barbering may be an important complex multi-domain behaviour sensitive to various manipulations, and represent a useful index in neurobehavioural research.