Oxytocin Alters Hormonal and Behavioral Responses to an Intruder in Marmoset Monkeys

Author #1

Abstract

In socially monogamous species, the intolerance and active discouragement of interactions between a mate and a stranger (i.e., mate-guarding) promotes the preservation of the long-term bond. The hormone oxytocin has attracted enormous interest as a neuromodulator of social, emotional, and cognitive processes, has been demonstrated to play a crucial role in the facilitation of social bonds and prosocial behavior, and has even been described as ‘the great facilitator of life’. Thus, the goal of this study was to examine the role the oxytocin system plays in the expression of mate-guarding behavior in marmoset monkeys. Male and female marmosets were exposed to a same-sex intruder in their home environment during conditions when their mate was present and when their mate was absent, crossed with three oxytocin treatment conditions. Male and female marmosets were significantly quicker to aggress toward an intruder, and had higher levels of cortisol and testosterone when their mate was present, compared to when their mate was absent. Saline-treated marmosets spent significantly more time in proximity to the intruder when their mate was absent. However, when marmosets were treated with oxytocin they spent less time in proximity to the intruder. In conditions when their mate was present, marmosets spent an equal amount of time in proximity to both the intruder and their mate. Yet, when they were treated with oxytocin they spent significantly more time in proximity to the intruder. These results suggest that while oxytocin reduces territoriality, it increases the expression of mate-guarding behavior and facilitates fidelity.

 
Mar 3rd, 1:00 PM Mar 3rd, 1:15 PM

Oxytocin Alters Hormonal and Behavioral Responses to an Intruder in Marmoset Monkeys

UNO Criss Library, Room 225

In socially monogamous species, the intolerance and active discouragement of interactions between a mate and a stranger (i.e., mate-guarding) promotes the preservation of the long-term bond. The hormone oxytocin has attracted enormous interest as a neuromodulator of social, emotional, and cognitive processes, has been demonstrated to play a crucial role in the facilitation of social bonds and prosocial behavior, and has even been described as ‘the great facilitator of life’. Thus, the goal of this study was to examine the role the oxytocin system plays in the expression of mate-guarding behavior in marmoset monkeys. Male and female marmosets were exposed to a same-sex intruder in their home environment during conditions when their mate was present and when their mate was absent, crossed with three oxytocin treatment conditions. Male and female marmosets were significantly quicker to aggress toward an intruder, and had higher levels of cortisol and testosterone when their mate was present, compared to when their mate was absent. Saline-treated marmosets spent significantly more time in proximity to the intruder when their mate was absent. However, when marmosets were treated with oxytocin they spent less time in proximity to the intruder. In conditions when their mate was present, marmosets spent an equal amount of time in proximity to both the intruder and their mate. Yet, when they were treated with oxytocin they spent significantly more time in proximity to the intruder. These results suggest that while oxytocin reduces territoriality, it increases the expression of mate-guarding behavior and facilitates fidelity.