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Sex differences in juvenile play behavior differ among rat strains
Author(s) -
Northcutt Katharine V.,
Nwankwo Vesta C.
Publication year - 2018
Publication title -
developmental psychobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 93
eISSN - 1098-2302
pISSN - 0012-1630
DOI - 10.1002/dev.21760
Subject(s) - juvenile , novelty , weaning , context (archaeology) , laboratory rat , developmental psychology , psychology , sibling , circadian rhythm , physiology , novelty seeking , biology , endocrinology , medicine , genetics , social psychology , paleontology , personality , temperament
Abstract Juvenile male rats frequently play more than female rats, but the presence of sex differences is affected by testing conditions and may also depend on the strain of rat. In this experiment, we tested play and defensive behaviors in male and female Long‐Evans, Sprague‐Dawley, and Wistar rats. When observed with a cage mate during the juvenile period, Long‐Evans rats played more than Wistar animals, but there were no sex differences in any strain. When tested with an unfamiliar sibling (not seen since weaning), both Long‐Evans and Wistar rats played more than Sprague‐Dawley animals, and Long‐Evans females played more than males. We did not observe any sex or strain differences in defensive behaviors. Our data indicate that there are strain differences in play behavior, and sex differences in play depend on both strain and context. Variation among strains may reflect underlying differences in anxiety, novelty seeking, and circadian rhythms.