TY - JOUR
T1 - Impairment of interstrain social recognition during territorial aggressive behavior in oxytocin receptor-null mice
AU - Hattori, Tatsuya
AU - Kanno, Kouta
AU - Nagasawa, Miho
AU - Nishimori, Katsuhiko
AU - Mogi, Kazutaka
AU - Kikusui, Takefumi
N1 - Funding Information:
This work was supported by JSPS KAKENHI (Grant Numbers 23248049 , 25660252 , 25118007 , and 26292167 ) and was partially supported by a research project grant awarded by Azabu University. T.H. and K.K. were supported by Research Fellowships from the Japan Society for the Promotion of Science for Young Scientists.
Publisher Copyright:
© 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - In humans, oxytocin has been shown to be involved in in-group cooperative behaviors and out-group aggression. Studies have also demonstrated that oxytocin plays a pivotal role in social recognition. However, no empirical research has investigated the effect of oxytocin on in-group and out-group aggressiveness. We employed a resident-intruder paradigm to assess the ability of resident male mice to discriminate intruder male strain differences. We found that resident male mice exhibited higher frequencies of attack bites against intruders of different strains than against intruders of their own strain. Subsequently, we examined whether the interstrain recognition was regulated by the oxytocin system using oxytocin receptor (OTR)-null mice. OTR wild-type or heterozygous residents displayed higher aggression toward intruders of a strain different from their own (C57BL/6J). On the other hand, OTR-null residents exhibited greater aggression toward intruders of the same strain compared to OTR wild-type or heterozygous residents, and aggression levels were not different compared to those exhibited toward other strains. Our findings demonstrated that the oxytocin system contributes to interstrain social recognition in territorial aggression in male mice, implying that one function of oxytocin is to promote an in-group "tend-and-defend" response, such as in-group favoritism, which could be evolutionarily conserved in mammals.
AB - In humans, oxytocin has been shown to be involved in in-group cooperative behaviors and out-group aggression. Studies have also demonstrated that oxytocin plays a pivotal role in social recognition. However, no empirical research has investigated the effect of oxytocin on in-group and out-group aggressiveness. We employed a resident-intruder paradigm to assess the ability of resident male mice to discriminate intruder male strain differences. We found that resident male mice exhibited higher frequencies of attack bites against intruders of different strains than against intruders of their own strain. Subsequently, we examined whether the interstrain recognition was regulated by the oxytocin system using oxytocin receptor (OTR)-null mice. OTR wild-type or heterozygous residents displayed higher aggression toward intruders of a strain different from their own (C57BL/6J). On the other hand, OTR-null residents exhibited greater aggression toward intruders of the same strain compared to OTR wild-type or heterozygous residents, and aggression levels were not different compared to those exhibited toward other strains. Our findings demonstrated that the oxytocin system contributes to interstrain social recognition in territorial aggression in male mice, implying that one function of oxytocin is to promote an in-group "tend-and-defend" response, such as in-group favoritism, which could be evolutionarily conserved in mammals.
KW - Aggressive behavior
KW - Interstrain recognition
KW - Oxytocin
KW - Oxytocin receptor
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U2 - 10.1016/j.neures.2014.05.003
DO - 10.1016/j.neures.2014.05.003
M3 - Article
C2 - 24929102
AN - SCOPUS:84922689675
VL - 90
SP - 90
EP - 94
JO - Neuroscience Research
JF - Neuroscience Research
SN - 0168-0102
ER -