Evaluation of two automated metrics for analyzing partner preference tests

Abstract

The partner preference test (PPT) is commonly used to examine sexual and social preferences in rodents. The test offers experimental subjects a choice between two stimulus animals, and time spent with each is used to calculate a preference score. In monogamous prairie voles (Microtus ochrogaster), the PPT has been paramount to the study of pair bonding. Although powerful, use of the PPT in voles has depended primarily on human manual scoring. Manual scoring is timeconsuming and is susceptible to bias and fatigue, limiting the use of the PPT in high-throughput studies. Here we compared manual scoring (real-time and 16x) and two automated scoring metrics: "social proximity" and "immobile social proximity" We hypothesized that "immobile social contact" would provide data most comparable to manually scored "huddling", and thus be the most sensitive measure of partner preference in prairie voles. Each automated metric produced data that highly correlated with manual scoring (R > 0.90); however, "immobile social contact" more closely reflected manually scored huddling (R = 0.99; P < 0.001). "Social proximity" and "immobile social contact" were then used to detect group partner preferences in four data sets that varied by cohabitation length and sex. "Immobile social contact" revealed a significant partner preference in each data set; "social proximity" detected partner preferences in only three of the four. Our results demonstrate the utility of automated systems in high-throughput PPTs, and further confirm that automated systems capable of scoring "immobile social contact" yield results indistinguishable from manual scoring.

RNAi knockdown of oxytocin receptor in the nucleus accumbens inhibits social attachment and parental care in monogamous female prairie voles

“…The latency and frequency to approach or attack the pups, as well as the duration of licking, carrying, huddling and retrieving the pups was recorded and scored by an observer blind to the experimental condition using Stopwatch (http://www.cbn-atl.org/research/stopwatch.shtml) as previously described (Ahern et al, 2009). Females were considered “alloparental” if they spent >30s huddling over the pups and >5s licking the pups without attacking as previously described (Olazábal and Young, 2005).…”

Activation of μ-Opioid Receptors in the Dorsal Striatum is Necessary for Adult Social Attachment in Monogamous Prairie Voles

“…After 24 h of cohabitation, all subjects were tested for partner preference using a modified partner preference apparatus as described previously (Ahern et al, 2009). During the PPT, 'social immobility' or huddling was defined by the CleverSys SocialScan software (CleverSys, VA) using an algorithm in which time spent in social contact while relatively immobile was counted.…”

Pair-bonding behaviour of the sister species Microtus lusitanicus and M. duodecimcostatus

“…We adapted original procedures, because M. lusitanicus and M. duodecimcostatus are very sensitive to constraining devices (personal observations), for example being tethered in separate boxes, in contrast with other Microtus voles (Williams et al 1992;Berteaux et al 1999;Aragona and Wang 2004;Ahern et al 2009). Tests were conducted from 11:00 to 17:00, when both species are active (Madureira 1984), in a separate room with similar temperature and photoperiod conditions as the colony room.…”