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Christopher Bloom, Ph.D.
Providence College
Katharine Phillips, M.D.
Brown University
BDD is characterized by preoccupation with perceived slight or imagined
physical flaws. Phillips & Diaz (1997) reported that in a sample of patients with
BDD, flaws in skin (65%) and hair (55%) were the most common bodily focus for
preoccupation, resulting in abnormal grooming bheaviors. A normally adaptive
behavior, grooming has been shown to become pathological in a number of
species. Additionally, repetitive grooming is exacerbated by environmental
stressors such as social isolation or restraint.
In a gene association study, Phillips & Kaye (2007) reported a significant
enrichment in a mutation in the gabrg2 gene localized on the human
Chromosome 5q. The gene encodes the GABAA-Ɣ2 subunit of the GABAA
receptor, a chloride channel that binds to GABA, the primary inhibitory
neurotransmitter in the brain. Phillips & Kaye (2007) report that the (A) allele was
enriched in BDD subjects when compared to healthy controls. The current study
investigates the impact of suppressed GABAA -2 expression on behavioral
indicators associated with grooming.
Animals were observed in their home cages for a period of 48 hours
utilizing computer vision observation software. This method quantified frequency,
intensity and pattern of grooming behaviors in gabrg2 mice in comparison to wildtype controls.
Our results indicate that grooming behaviors in gabrg2 mice differ
significantly from wild-type controls. Further development of this model may
provide critical translational tool for understanding the neurobiological basis of
this devastating disorder.