title: Impaired social recognition memory in recombination activating gene 1-deficient mice.
abstract: The recombination activating genes (RAGs) encode two enzymes that play key roles in the adaptive immune system. RAG1 and RAG2 mediate VDJ recombination, a process necessary for the maturation of B- and T-cells. Interestingly, RAG1 is also expressed in the brain, particularly in areas of high neural density such as the hippocampus, although its function is unknown. We tested evidence that RAG1 plays a role in brain function using a social recognition memory task, an assessment of the acquisition and retention of conspecific identity. In a first experiment, we found that RAG1-deficient mice show impaired social recognition memory compared to mice wildtype for the RAG1 allele. In a second experiment, by breeding to homogenize background genotype, we found that RAG1-deficient mice show impaired social recognition memory relative to heterozygous or RAG2-deficient littermates. Because RAG1 and RAG2 null mice are both immunodeficient, the results suggest that the memory impairment is not an indirect effect of immunological dysfunction. RAG1-deficient mice show normal habituation to non-socially derived odors and habituation to an open-field, indicating that the observed effect is not likely a result of a general deficit in habituation to novelty. These data trace the origin of the impairment in social recognition memory in RAG1-deficient mice to the RAG1 gene locus and implicate RAG1 in memory formation.
authors.affiliation: Department of Psychology and Neuroscience, Duke University, Durham, NC 27708, USA. patrick.mcgowan@utoronto.ca
authors.forename: Patrick O
authors.initials: PO
authors.lastname: McGowan
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Hope
authors.forename: Warren H
authors.initials: WH
authors.lastname: Meck
authors.forename: Garnett
authors.initials: G
authors.lastname: Kelsoe
authors.forename: Christina L
authors.initials: CL
authors.lastname: Williams
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D016654:Genes, RAG-1 / Q000235:genetics*; D007398:Interpersonal Relations; D008568:Memory / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D021641:Recognition, Psychology / Q000502:physiology*