Mineralocorticoid and glucocorticoid receptor mRNA expression in the brain of translocated chukar (Alectoris chukar)

Although translocation is an important conservation tool in the effort to create self-sustaining wild populations of threatened species, avian translocations have a high failure rate and causes for failure are poorly understood. While “stress” is considered to play a major role in translocation failure, the physiological changes associated with chronic stress resulting from translocation have been investigated only recently. Translocation results in chronic stress-induced alterations of stress response physiology in the chukar (Alectoris chukar) and in the present study we tested the hypothesis that changes in the hypothalamic-pituitary-adrenal axis (HPA) are correlated with changes in the brain, specifically at the level of the glucocorticoid and mineralocorticoid receptors (GR and MR, respectively) in the hippocampus and hypothalamus. Our previous research has shown that there are apparent changes in GR and MR expression in the brain of experimentally chronically stressed European starlings (Sturnus vulgaris). In the present study however, translocation had no major detectable effect on levels of GR or MR mRNA expression in the hippocampus or hypothalamus of wild chukar suggesting that the observed dysregulation of the HPA axis by translocation may not be a result of such upstream changes.

Research highlights► GR mRNA expression was observed widely across the telencephalon of the chukar. ► MR mRNA expression was restricted to specific regions of the chukar brain. ► Translocation does not have a robust effect on hippocampal GR or MR expression. ► Translocation-induced chronic stress does not change hypothalamic GR expression.