Phenotyping and genetics of rodent grooming and barbering: Utility for experimental neuroscience research

Summary Grooming and barbering (behavior-associated hair loss) are complex, ethologically rich behaviors. They are commonly observed in different animal species, and represent important phenotypes to study in experimental models utilizing rodent research. Due to sensitivity to alterations in activity and microstructure, grooming analysis has utility in the assessment of stress in individual animals, the testing of psychotropic drugs, phenotyping mutant or transgenic animals, as well as the selection of proper strains for experimental modeling of affective disorders. Similarly, barbering shows context- and strain-specific variations, and may serve as an indicator of social dominance or behavioral perseveration. While little is known about the genetics of barbering phenotypes, evaluation of this behavior has implications in neurophysiology and biological psychiatry, providing insight into trichotillomania, obsessive–compulsive disorder (OCD), aggression-related and other human brain disorders. Here, we discuss ethologically based approaches to the assessment of animal grooming and barbering activity. Additionally, we present examples of genetic variation leading to altered grooming and barbering phenotypes in rodents, and summarize the growing value of these two phenotypes for translational neurobehavioral research. Introduction Grooming is an innate behavior shared across many animal species with remarkable homology (Fentress 1988; Sachs 1988; Spruijt et al. 1992). Common in laboratory and wild rodents, grooming occupies a substantial portion of their waking time, thereby representing an important phenotype to study (Bolles 1960; Hyman 2007; Kalueff et al. 2007a; Kalueff and Tuohimaa 2004a, 2005a).