The intruder-resident paradigm has been extensively employed in studies of social recognition memory in rodents. Typically, adult rats (residents) are exposed to two 5-min encounters with the same juvenile intruder or with two different juveniles; the interval between the encounters is 30 min. The amount of social behaviors exhibited by the resident rats toward the same intruder juvenile in the second encounter is substantially smaller when compared to both that seen in the first encounter and that seen toward a different juvenile; these results characterize social recognition memory. In this study we discuss recent findings related to behaviors usually included as social and non-social, the influence of the temporal phase on social behavior, the interference of laboratory routines on social recognition memory, sensory modalities usually employed by rodents for processing relevant information in the social memory and additional alternatives to study sociability in these animals.
Intruder-resident paradigm; Social behavior; Rats; Social investigative behaviors; Social agonistic behaviors
