Short duration of retroactive facilitation of social recognition in rats

Adult rats spent less time investigating the same juvenile during a second dyadic encounter session. This decrease served as an index for social recognition. Social recognition was not influenced by isolating the juveniles for 7 days prior to experimentation. Retroactive facilitation of social recognition was observed when the two rats were confronted for a longer period of time on a given day by multiple testing. However, this facilitation was not observed after a 24-h interexposure interval between encounter sessions, even when different housing conditions during that time were taken into account, and animals were tested during 5 consecutive days. It is suggested that social recognition may be a form of short-term memory.