Genome-wide scan for quantitative trait loci influencing spatial navigation and social recognition memory in Dahl rats

1 Section of Molecular Medicine, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 2 Center for Behavioral Development and Mental Retardation, Boston University School of Medicine, Boston, Massachusetts The genetic determinants of learning and memory have been difficult to unravel because of the complex inheritance of these forms of cognitive behavior encompassing multiple genetic and environmental factors. Indeed, genes that can account for strain and individual variations in learning and memory are largely unknown. Here we report a genome-wide scan for quantitative trait loci (QTLs) affecting spatial learning and memory and social recognition memory in an F 2 population derived from Dahl rats. We detected five QTLs on chromosomes 1, 8, 11, 17, and 20 affecting spatial acquisition performance and five QTLs on chromosomes 2, 3, 9, and 20 influencing spatial accuracy (once information about the target location had been acquired). None of these QTLs overlap, indicating the existence of independent genetic determinants for these two distinct behavioral components of spatial navigation. Moreover, five QTLs affecting social recognition memory were detected, two on chromosome 9 and three on chromosome X. The chromosomal regions linked to social recognition memory performance in the rat are syntenic to regions that have been linked to autism in humans. Thus our results could have paradigmatic value in guiding the experimental investigation of similar pathways in genetic susceptibility to this disorder, which results in profound impairments in social behavior. genetics; Morris water maze; acquisition; spatial accuracy