Short-latency stressor effects on tonic immobility fear reactions of Japanese quail divergently selected for adrenocortical responsiveness to immobilization.
Despite evidence for a positive association between adrenocortical activation and fearfulness, the effects of chronic (12 to 20 h) exposure to stressful stimulation on the fear reactions of Japanese quail genetically selected for high (HS) or low (LS) plasma corticosterone response to immobilization stress are not straightforward. The present study examined tonic immobility fear responses in quail of both lines that, immediately prior to testing, either had been allowed to remain undisturbed or had been exposed to an acute stressor similar to that used in the selection program (i.e., a short-latency stressor; 5 min of immobilization). Tonic immobility responses were generally more pronounced in quail of the HS line than the LS line, and they were exaggerated in both lines after exposure to stress treatment. The findings provide further support for the suggestion that selection for exaggerated or reduced adrenocortical responsiveness may have been accompanied by a concomitant and unconscious effect on underlying fearfulness.
Satterlee
D G
DG
Department of Poultry Science, Louisiana State University, Baton Rouge 70803.
Jones
R B
RB
Ryder
F H
FH
D000302:Adrenal Cortex / Q000502:physiology; D000818:Animals; D003345:Corticosterone / Q000097:blood; D003370:Coturnix / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D007103:Immobilization / Q000502:physiology; D008297:Male; D013045:Species Specificity; D013315:Stress, Psychological / Q000097:blood
D003345:Corticosterone