Meeting Abstract
Following stressor exposure, organisms mount physiological and behavioral responses aimed at survival to enable species perpetuation. Two major physiological responses include the glucocorticoid (GC) stress response and the heat shock response, mediated by heat shock proteins (HSPs). There have been some studies into GC and HSP interactions, which suggests the two may interact and possibly even mediate one another. However, how these responses interact is not clear in part because it is hard to compare studies that measure constitutive (always active; cHSPs) and/or inducible (stress-induced; iHSPs) HSPs at various times after stressor exposure. In some studies, samples may have been taken too rapidly to understand how stress-induced GC levels affect HSPs. As such, our aim in this study was to utilize a commonly used stressor (heat stress) to examine how stressors affect circulating levels of cHSPs, iHSPs, and GCs over time. In this study, 26 (13/treatment) female zebra finches (Taeniopygia guttata) were either heat stressed (38°C) or put in a control incubator at room temperature for 3 hours. They were then returned to cages and left alone until blood sampling 2, 4, 6, and 20 hours after treatment ended. Baseline blood samples were obtained a week before treatment. Plasma corticosterone, along with erythrocyte HSPs were measured. Constitutive HSP70 (i.e., HSC70) levels were significantly reduced after 2 and 4 hours, regardless of treatment (p=0.0104), suggesting an impact of handling stress on this reduction. However, no effect of Time or Treatment was observed on corticosterone (CORT) levels, suggesting the birds may be habituated to repeated sampling or that the temperature was not high enough to induce changes in CORT. Results are forthcoming regarding effects on inducible HSP70 and HSP90. Our study should provide a basis for further research into HSP and GC crosstalk.
