Studies of interaction between psychological state and food intake on gastrointestinal motility, splanchnic perfusion and autonomic nervous system in

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Abstract A relationship between psychological state such as stress and emotions and feeding behaviour is known to exist, and yet the physiological basis of this interaction remains incompletely understood. It appears likely that the physiological stress response systems such as the autonomic nervous system, Hypothalamic Pituitary Adrenal (HPA) Axis and satiety hormones play an important modulatory role in this relationship. Previous research has focused on isolated GI sensory-motor responses and relied upon subjective symptom reports or investigations that require intubation or exposure to ionising radiation to assess key physiological processes involved in digestion. The primary aim of this PhD project is to validate novel computational approaches and advanced imaging techniques in both human and preclinical rodent models to measure these simultaneously and minimally invasively. Validation of these methods would provide further insight into physiological mechanisms in health and disease; enable the stratification of patients who present with similar symptoms (e.g. dyspepsia) but different underlying pathologies (e.g. altered motility, altered accommodation, altered splanchnic circulation); provide an objective way of determining treatment response in clinical trials; and support the identification of novel biomarkers and therapeutic targets. Nutrient and drug challenges will be used to provoke changes in appetite-related sensations and upper GI symptoms and their effect on the autonomic nervous system (using heart rate and respiratory variability) and gastrointestinal motility (using magnetic resonance imaging, MRI) in healthy human subjects. The interaction between these parameters and personality traits, body perception and emotional state will be characterised using validated questionnaires and assessments to better understand the complex interface between psychological and physiological processes. In vivo imaging of gastrointestinal transit will also be applied to rodent models of accelerated or delayed transit.