Androgenic induction of brain sexual dimorphism depends on photoperiod in meadow voles.
Male meadow voles maintained in a long photoperiod (LP) from birth have heavier brains than do females, but in short photoperiods (SP) this sex dimorphism is absent. Testosterone propionate (TP) administration on the second day of postnatal life produced significant increases in brain weight of LP but not SP females at 35 days of age. Short daylengths reduce the responsiveness of the meadow vole nervous system to the masculinizing effects of perinatal testosterone and may, in part, mediate the seasonally reduced sex difference in brain weight.
Kelly
K K
KK
Department of Psychology, University of California, Berkeley 94720.
D000818:Animals; D003411:Arvicolinae / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D001921:Brain / Q000502:physiology*; D005260:Female; D008027:Light; D008297:Male; D009929:Organ Size / Q000502:physiology; D012621:Seasons; D012733:Sex Differentiation / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology; D012741:Sexual Maturation / Q000502:physiology*; D013739:Testosterone / Q000502:physiology*
D013739:Testosterone