1. Coping with Stress: Does having a single parent affect offspring of typically biparental zebra finches (Taeniopygia guttata) Leslie S. Phillmore, Jordan Fisk, Sean D. Aitken, Tareq Yousef, Tara S. Perrot Departments of Psychology and Neuroscience 1 and Biology 2 Introduction Dalhousie University, Halifax, NS Canada Conclusions Future Directions References Acknowledgments 1. McLeod J, Sinal CJ, Perrot-Sinal TS. (2007) Evidence for non-genomic transmission of ecological information via maternal behavior in female rats. Genes Brain Behav 6:19-29. 2. Royle NJ, Hartley IR, Parker GA. (2006) Consequences of biparental care for begging and growth in zebra finches, Taeniopygia guttata. Anim Behav 72:123-130. 3. Banerjee, SB, Arterbery AS, Fergus DJ, Adkins-Regan E. (2012) Deprivation of maternal care has long-lasting consequences for the hypothalamic-pituitary-adrenal axis of zebra finches. Proc R Soc B 279:759- 766. 4. Schmidt KL, Chin EH, Shah AH, Soma KK. (2009) Cortisol and corticosterone in immune organs and brain of European starlings: developmental changes, effects of restraint stress, comparison with zebra finches. Am J Physiol Reful Interg Comp Physiol; 297: R42-R51. Results Methods Offspring Physiology Offspring Behaviour Offspring Behaviour: Offspring of single mothers were fed fewer times but also begged less than offspring in biparental and single father nests. Offspring Physiology: All offspring, regardless of rearing condition, gained weight from PHD 8 to PHD 13, despite single-mothers feeding at a lower rate. Single-mothers may be feeding more food in one feeding bout OR offspring of single mothers may move less to conserve energy – e.g. less begging. Female offspring had higher baseline CORT than males. GCR Results: Preliminary data was too small to reveal significant statistical results. However, it appears females reared by a single mother have increased GCRs in Hp, indicating they may have more resilience to cope with higher levels of circulating CORT. Analyse remaining sections for GCR in Hp and other areas. Analyse relationships among GCR levels, CORT levels, and parental and offspring behaviours. Behaviors Recorded WeightsFeeds receivedBegging (time, intensity) Glucocorticoid Receptors Video Analyses Modeling effects of developmental stress primarily uses rodents where only maternal care is provided 1. Zebra finches provide bi-parental care to offspring, allowing us to test effects of either mother or father removal on parent and offspring behaviours and stress levels 2. Previous work in finches showed removal of mother had no effect on GCR mRNA in the hippocampus 3. In this study we removed either the father or the mother of a brood and examined: Offspring behaviour in first 2 weeks post hatch Baseline and acute stress response levels of corticosterone 4 Number of glucocorticoid receptors (GCRs) in hippocampus Analyzed 2h of video Sampled behaviour for 1 min every 5 min Total of 24 one-min samples Jill Squires collected the behavioural data. Ashley Lockyer, Dominique Shephard, and Jaya Wadhawan helped with bird care, video recording, and project management. 539.11 CC11 * * Offspring reared in single mother nests had higher circulating CORT than offspring reared in single father nests, but did not differ from biparental offspring. Females had higher CORT than males. After exposure to acute stress, CORT levels rose significantly over baseline. Offspring weighed more on PHD 13 than PHD 8 (F (F(1,34)= 177.10, p <0.001). On PHD 8, offspring in biparental nests weighed significantly less than offspring in single father nests (F(2,41)= 5.72, p =0.01). Offspring begged less on PHD 13 than on PHD 8 (F(1,12)= 5.45, p=0.04), and offspring in single mother nests begged less than offspring in both biparental and single father nests on both PHD 8 and 13 (F(2,12)= 10.90, p=0.002). On PHD 13, offspring in single mother nests received fewer feeds than offspring in biparental nests (F(2,14)= 5.25, p= 0.02). Error bars represent standard errors of the means. Pairs of finches allowed to breed Biparental Father or mother removed 4-5d post hatch Video tape parental/offspring behaviour Allow birds to mature Collect blood from offspring throughout development Expose to acute stressor (restraint) and collect blood Baseline blood of offspring was collected within five minutes of entering the room at PHD 30, 90, 120. Acute stress was induced by holding the bird in a cloth bag for 30 min before blood collection 4. Plasma cort levels were quantified using a standard ELISA kit (ADI- 901-097, Enzo Life Sciences). Immunohistochemistry for GCR protein (PA1510A Life Technologies at 1:1000 followed standard steps and was visualized with DAB. Process blood for baseline and acute CORT levels Section brains and process for GCR protein (IHC) Males – separated by hemisphereFemales – separated by hemisphere Averaged across hemispheres A: Coronal section of left hemisphere showing the ROI in hippocampus (Hp), taken at 4x. B: Hp at 20x used for counting GCR+ cells. A B We counted the number of cells labeled with GCR (GCR+) in hippocampus; we used two birds of each sex in each rearing group. We analysed the data using non parametric tests. There was no difference in number of GCR+ cells between left and right hippocampus (Wilcoxon p=0.14). Males and females did not differ in number of GCR+ cells in hippocampus (K-S test p=0.44). There were no differences across rearing conditions in number of GCR+ cells.