Oxytocin Induces Sex-Specific Changes in Territorial Defense by Pair-Bonded California Mice

Meeting Abstract

32-4  Thursday, Jan. 4 14:15 – 15:00  Oxytocin Induces Sex-Specific Changes in Territorial Defense by Pair-Bonded California Mice RIEGER, NS*; MARLER, CA; Univ. of Wisconsin; Univ. of Wisconsin nrieger@wisc.edu

Monogamous pair bonding allows for division of labor and coordination of complex social behaviors within a pair. While oxytocin (OT) influences formation and maintenance of pair bonds in monogamous species, its role in division of labor and territorial defense by pair-bonded individuals is unknown. We studied OT’s role in territorial defense by pair-bonded California mice (Peromyscus californicus). Previously we found that resident pairs of California mice use either male only or female only divided defense or joint defense against territorial intruders, with pairs maintaining a single strategy across varied conditions. To elucidate the role of OT, we administered an intranasal dose (0.8 IU) of OT to either both members of the pair or only the male or female of the pair 5-min prior to a territorial intrusion. OT revealed sex specific differences in defense coordination and vocal communication (ultrasonic vocalizations) during territorial intrusions. When females but not males, received OT, pairs were more likely to divide defense (Female; OT: 61%, Saline: 36%), and females were more likely to act as the defender than in any other condition (Female; OT defenders: 85%, Saline Defenders: 50%). When males but not females, received OT, call duration was shortened (Male; OT: 112 ± 9.9 ms, Saline: 298 ± 31 ms). When both individuals received OT, pairs both increased divided defense (Both OT: 61%, Saline: 36%) to female only levels and shortened calls (Both OT: 197 ± 27 ms, Saline: 298 ± 31 ms) to male only levels. Overall, hormone administration revealed that OT induced greater behavioral plasticity in defense in females, while inducing greater behavioral plasticity in ultrasonic vocalizations in males, illustrating a sex specific role for oxytocin in territorial defense. (NSF Grant IOS1132419)

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