Episodic memory and reproductive condition could independently influence the pair bond maintenance in the male prairie vole (Microtus ochrogaster): Ecological implications and translational relevance in the study of sub-clinical manifestations of schizophrenia

Investigations on mating tactics of the prairie vole (Microtus ochrogaster, a socially monogamous rodent) have suggested that reproductive pair bonding and monogamy in this species are associated with increased capacity for social-spatial memory. In the present study, we tested this possibility in male voles that had been co-housed for an extended period with a female, by applying a behavioral test designed to assess familiarity recollection (FR) and novelty detection (ND) components of social, object, social-spatial, and object-spatial memory. We also assessed each male vole’s preference to display affiliative behavior toward his mate, relative to an unfamiliar female, as well as the reproductive success of the pair. We found that ND of social-spatial stimuli and reproductive success were independent positive predictors of the male’s affiliative preference for his partner female. ND of social, object, and object-spatial stimuli were not associated with male affiliative preference, nor were FR responses to any of these stimuli. Reproductive success was associated with both object-spatial and social-spatial ND. Taken together, the present results indicate that pair bond maintenance in the prairie vole is importantly associated with increased detection of and/or attention to alterations in associations between individual conspecifics and their spatial location. Independently, reproductive success appears to favor detection of object-spatial and social-spatial novelty. These results are discussed in relation to vole natural history, as well as in the context of their possible significance for elucidating relationships between episodic memory deficits and dysfunctional social behavior in pathological conditions such as schizophrenia.