DIFFERENTIAL PROLACTIN RESPONSIVENESS TO STRESS IN LEFT-PAWED AND RIGHT-PAWED MICE

Behavioral laterality has been shown to be related to immunological an d endocrinological responsiveness in mice. The current study extended these findings by examining: the pituitary hormone prolactin, and its response to stress, in left- and right-pawed mice. In two experiments, mice were rested on two measures of behavioral laterality, the Collin s paw preference test and the Lateral Paw Preference (LPP) lest. Circu lating PRL levels were then measured in all subjects under baseline an d stressed conditions. In Experiment 1, the PRL stress response tvas r elated to Collins paw preference in interaction with coat-color among females of a genetically heterogeneous group. Left-pawed black females showed a significant increase in PRL, while right-pawed black females did not. Among agouti mice, left-pawed females showed a significant d ecrease, while right-pawed did not. Experiment 2 used a genetically ho mogeneous group of agouti C3H mice. Again there were effects of Collin s paw preference among females, with the right-pawed showing a signifi cant increase in PRL following stress. in neither experiment were ther e effects of LPP, In neither experiment were there lateralized differe nces among males. These results indicate lateralized regulation of PRL among females, similar to that previously observed for ACTH regulatio n.