title: Abnormal behavioral organization of grooming in mice lacking the vitamin D receptor gene.
abstract: Vitamin D is a steroid hormone with several important functions in the nervous system. Numerous human and animal data link alterations in the vitamin D system to various behavioral disorders. Grooming is an important element of rodent behavior with a general pattern of cephalocaudal progression (paw licking - nose/face wash - body wash - tail/genitals wash). Here we studied whether genetic ablation of vitamin D nuclear receptors (VDR) in mice may be associated with altered behavioral sequencing of grooming. Overall, VDR null mutant mice showed abnormal grooming, including a higher percentage of "incorrect" transitions and longer duration of "incorrect" grooming (contrary to the cephalocaudal progression); a higher percentage of interrupted grooming bouts; and the atypical regional distribution of grooming (more leg grooming, less body and tail/genitals grooming), compared to their wild-type controls. Grooming of heterozygous mice was similar to the wild-type group, indicating that abnormal grooming patterning is inherited as a recessive. In contrast, behavioral sequencing of another complex behavior (mating with a female) was unaltered in all three genotypes, suggesting grooming-specific abnormal sequencing in these mutant mice. Our results suggest that a neurosteroid vitamin D and VDR may play an important role in controlling sequencing of grooming in mice, and further confirm the important role of the vitamin D system and VDR in the regulation of behavior.
authors.affiliation: Department of Anatomy, Medical School, University of Tampere, Tampere, Finland. avkalueff@inbox.ru
authors.forename: Allan V
authors.initials: AV
authors.lastname: Kalueff
authors.forename: Yan Ru
authors.initials: YR
authors.lastname: Lou
authors.forename: Ilkka
authors.initials: I
authors.lastname: Laaksi
authors.forename: Pentti
authors.initials: P
authors.lastname: Tuohimaa
mesh_terms: D000818:Animals; D005260:Female; D006120:Grooming / Q000502:physiology*; D006579:Heterozygote; D006720:Homozygote; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D018167:Receptors, Calcitriol / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology
chemical_list: D018167:Receptors, Calcitriol