Research note: open-field behavior of Japanese quail chicks genetically selected for low or high plasma corticosterone response to immobilization stress.

Open-field behavior was examined in Japanese quail chicks genetically selected for either reduced (LS, low stress) or exaggerated (HS, high stress) plasma corticosterone response to immobilization stress. Chicks of the LS line showed less freezing and ambulated sooner than did their HS counterparts. These findings suggest that exposure to an open-field or novel environment elicited less fear in LS than in HS chicks. They also support the suggestion that fearfulness and adrenocortical activation are positively associated and indicate that selection for differential adrenocortical responsiveness exerted concomitant effects on fear-related behavior.