Expansion of Olfactory-Based Social Recognition Memory Research: The Roles of Vasopressin and Oxytocin in Social Recognition Memory

Abstract

This chapter discusses the roles of vasopressin (VP) and oxytocin (OT) in rodent olfactory-based social recognition memory (SRM). The conventional paradigm used to test SRM in rats and mice is the social recognition test (SRT). A significant reduction in the duration of social investigatory behavior of a stranger juvenile, when it is reintroduced in a second five-min exposure period after a designated interexposure interval (IEI), is operationally defined as SRM. Control test sessions in which a novel juvenile is presented after the IEI are generally included to ensure that any reduced investigative behavior of the same juvenile by the subject is not merely the result of satiation, fatigue, or nonspecific drug effects. The social discrimination test (SDT) is used as an alternative paradigm for testing this type of memory. In the SDT the familiar juvenile and a novel juvenile are simultaneously presented during the second investigative encounter. The social recognition depends on two types of memory processes, short-term and long-term, and they appear to be differentially sensitive to the facilitating effects of various arginine vasopressin (AVP)-related peptides.