Meeting Abstract

P3.165  Tuesday, Jan. 6  Transient disruption in corticosterone negative feedback resulting from captivity DICKENS, M. J.*; ROMERO, L. M.; Tufts University; Tufts University molly.dickens@tufts.edu

Maintaining wild animals in captivity has long been used for conservation and research. While the potential for causing chronic stress has been widely suggested, how captivity affects the underlying stress physiology is poorly understood. In our study, we used a model species, chukar (Alectoris chukar) to assess the effects throughout ten days of captivity on the corticosterone (CORT) secretory pathway: the Hypothalamic-pituitary-adrenal (HPA) axis. Specifically, we were interested in the changes in negative feedback sensitivity along the axis since many studies have linked chronic stress to a disruption in CORT secretion feedback. To test changes in negative feedback we used two approaches. In one experiment, we restrained the individuals for 15 minutes in a cloth bag and then injected, intramuscularly, a synthetic glucocorticoid, dexamethasone (DEX), to stimulate negative feedback and sampled for CORT 30 minutes after the injection. In the second experiment, we restrained individuals for 30 minutes and then returned them to the aviary, thus ceasing the stressor, and allowed 30 minutes without disruption before sampling for CORT. In both experiments the strength of negative feedback (as indicated by the decrease in CORT over the 30 minutes) decreased by day 5 but was regained by day 9. We concluded that introduction into captivity shifted the chukar into a state of chronic stress; however, the observed alterations to negative feedback began to recover by day 9. Also, since the patterns of disrupted negative feedback across the days of captivity, as determined by DEX stimulation, corresponded to the pattern seen while using stressor cessation (natural negative feedback), these data demonstrate the validity of using the DEX suppression test as an indication of negative feedback disruption.