EFFECTS OF GONADECTOMY IN INFANCY AND ADULTHOOD ON HANDEDNESS IN MALEAND FEMALE MONGOLIAN GERBILS

When assuming a species-typical tripodal posture, female Mongolian ger bils most often rest on their left forepaws and hold their right forel imbs aloft; male gerbils most often do the reverse. This experiment ex amined effects of gonadectomy, both in infancy and in adulthood, on th e sexually dimorphic asymmetry in forelimb use by Mongolian gerbils wh en maintaining a tripodal stance. In adulthood, both male and female g erbils that had been gonadectomized at birth reversed their forelimb u se while in a tripodal stance: Gonadectomized males used their forelim bs as did sham-operated females, and gonadectomized females used their forelimbs as did sham-operated males. Gonadectomy in adulthood abolis hed the sexual dimorphism in forelimb use seen in sham-operated subjec ts. It was concluded that gonadal hormones have organizational as well as possible activational effects on adult patterns of forelimb use by gerbils.