Friday, 8^th April, 2016

16.00 – 17.00 - Room OS6 – Oakfield House

 Stafford Lightman, Professor of Medicine and Director, Henry Wellcome Laboratories

For the Integrative Neuroscience and Endocrinology

 and

 John Terry, Professor of Bioimedical Modelling and Director, EPSRC Centre for Predictive Modelling in Healthcare

  

“Stress: Is it all in the head? The dynamic rhythms of the hypothalamus-pituitary-adrenal axis”

 

Abstract

Oscillating levels of adrenal glucocorticoid hormones are essential for optimal gene expression, and for maintaining physiological and behavioural responsiveness to stress. The biological basis for these oscillations is not known, but a neuronal ‘‘pulse generator’’ within the hypothalamus has remained a popular hypothesis. In this talk we present evidence from both mathematical and experimental models that demonstrates that pulsatile hypothalamic activity is not required for generating ultradian glucocorticoid oscillations. In contrast, we show that a constant level of corticotrophin-releasing hormone (CRH) can activate a dynamic pituitary-adrenal peripheral network to produce ultradian adrenocorticotrophic hormone and glucocorticoid oscillations at physiologically realistic frequencies. This oscillatory response to CRH is dose dependent and becomes disrupted for higher levels of CRH. These data suggest that glucocorticoid oscillations result from a sub-hypothalamic pituitary-adrenal system, which functions as a deterministic peripheral hormone oscillator with a characteristic ultradian frequency. This constitutes a novel mechanism by which the level, rather than the pattern, of CRH determines the dynamics of glucocorticoid hormone secretion. If time permits, we will explore the consequences of these dynamics, particularly with regards delivery of acute stressors

Biography

John Terry is Professor of Biomedical Modelling and Director of the EPSRC Centre for Predictive Modelling in Healthcare. He develop techniques in applied dynamical systems and aligned computational methods which he uses to understand a variety of biological, biomedical and clinical problems. Current areas of focus include epilepsy, endocrinology and cardiac (dys)function.

Stafford Lightman is professor of Medicine and Director of the Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology.He is president-elect of the British Neuroscience Association. His research focusses on the importance of HPA rhythms for homeostatic regulation and optimal cognitive and metabolic function.

 

ALL WELCOME