Specificity in Sociality: Mice and Prairie Voles Exhibit Different Patterns of Peer Affiliation

Abstract

Social behavior is often described as a unified concept, but highly social (group-living) species exhibit distinct social structures and may make different social decisions. Prairie voles (Microtus ochrogaster) are socially monogamous rodents that often reside in extended family groups, and exhibit robust preferences for familiar social partners (same- and opposite-sex) during extended choice tests, although short-term preferences are not known. Mice (Mus musculus) are gregarious and colonial, but in brief laboratory tests of social preference they typically prefer social novelty. This preference for novel vs. familiar peers may represent a species-specific difference in social decision-making between mice and prairie voles. However, the tests used to measure preferences in each species differ markedly in duration and degree of contact, such that the behaviors cannot be directly compared. We assessed whether social preferences for novelty or familiarity differed between mice and prairie voles of both sexes when assessed with matching protocols: the sociability/social preference test (SPT) typically used in mice (short, no direct contact), and the partner preference test (PPT) used in voles (long, direct contact). A subset of voles also underwent a PPT using barriers (long, no direct contact). In the short SPT, behavior did not differ between species. In the longer test, pronounced partner preferences emerged in prairie voles, but mice exhibited no social preferences and rarely huddled. No sex differences were evident in either test. Direct physical contact was required for partner preferences in huddling time in voles, but preference for the partner chamber was evident with or without contact. Both prairie voles and mice are social, but they exhibit important differences in the specificity and extent of their social behavior. While mice are often used to study social approach and other behaviors, voles are a more suitable species for the study of selective social relationships. Consideration of these differences will be important for studies examining the neural mechanisms supporting different kinds of peer social behavior.

Inclusion of females does not increase variability in rodent research studies

“…Larger samples always provide better potential for analysis, and many have called for fewer studies performed on more individuals, particularly in neuroscience[36]. Sub-division of this sample into males and females and use of factorial designs is an effective method of analysis both in theory and in practice[37]. …”

Brain functional connectivity modulates social bonding in monogamous voles

“…In other words, baseline functional connectivity predicts how quickly subjects would begin affiliative huddling with an opposite sex conspecific. Huddling is a measurable affiliative behavior in prairie voles and a useful indicator of social receptiveness (Beery et al, 2018; Salo et al, 1993). The larger network included four nodes, related as follows: ACC-NAcc-BLA-DG (Figure 5), while the other two only included two nodes: MeA-VP and VTA-RSC.…”

What’s in a Moment: What Can Be Learned About Pair Bonding From Studying Moment-To-Moment Behavioral Synchrony Between Partners?

“…There is growing evidence that the neurobiological mechanisms supporting pair bonds change over time, particularly between formation and maintenance ( Aragona et al, 2006 ; Prior and Soma, 2015 ; Resendez et al, 2016 ; Scribner et al, 2019 ). More broadly, the neurobiology of social bonds also varies by relationship type ( Beery et al, 2008 , 2009 , 2018 ). Behaviorally, both within and across species, pair bonds vary in many dimensions including duration and apparent strength of the bond ( Black and Hulme, 1996 ; Tecot et al, 2016 ).…”