A multi-modal approach addressing brain-gut-interaction in Irritable Bowel Syndrome

• Applicant: Dr. Adriane Icenhour
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology ; General, Cognitive and Mathematical Psychology ; Human Cognitive and Systems Neuroscience
• Term: from 2015 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 289218302

Irritable Bowel Syndrome (IBS) is characterized by recurrent abdominal pain and disturbed bowel habits in the absence of an identifiable organic cause and with to date essentially unknown etiology and pathophysiology. Several mechanisms have been proposed to underlie IBS symptoms and the relevance of intestinal barrier dysfunction, altered central processing and psychological factors is increasingly appreciated, inspiring concepts of IBS as a disorder of brain-gut-communication. However, the complex, heterogeneous pathophysiology remains incompletely understood and biomarkers are lacking, calling for interdisciplinary research elucidating the dysfunctional interplay between intestinal disturbances, central changes and affective symptoms in IBS. Therefore, the objective of the proposed studies is to integrate multi-modal brain imaging techniques, psychological dimensions and measures of intestinal barrier function to address the following aims: 1. Alterations in structural and functional brain connectivity involving circuits of emotional pain processing in IBS are assumed to relate to both, affective disturbances and intestinal barrier dysfunction, substantially explaining variance in IBS symptoms. In IBS patients compared to healthy controls, resting state functional magnetic resonance imaging and diffusion tensor imaging will be performed to characterize patterns of functional and structural connectivity, hypothesizing alterations in IBS in brain regions involved in sensory and emotional pain processing and modulation. Affective disturbances are expected to relate to aberrant connectivity and explain differences in gastrointestinal symptoms in IBS. Alterations in brain connectivity and emotional disturbances are assumed to be associated with barrier dysfunction. 2. Amygdala and anterior insula represent key structures in emotional facets of pain processing. By contributing to impaired inhibitory control and enhanced symptom-related emotional responding, an imbalance between excitatory glutamatergic and inhibitory GABAergic neurotransmitter concentrations within these regions may constitute a central link between emotional disturbances and IBS symptoms. Quantitative magnetic resonance spectroscopy will be performed in IBS patients and healthy controls to determine concentrations and proportions of glutamate and GABA within amygdala and anterior insula and address associations with altered connectivity, intestinal barrier dysfunction and emotional factors. The proposed projects are embedded in a broad research plan implemented at the host institution, include innovative, established methodology and are well-designed in close interdisciplinary collaboration. This environment provides an excellent framework for the investigation of brain-gut dysfunction and its pathways in IBS towards a better characterization of patients and a broader understanding of mechanisms underlying IBS symptoms and frequent comorbidities with affective disturbances.

• DFG Programme: Research Fellowships
• International Connection: Sweden
• Hosts: Professor Dr. Anders Persson; Professorin Dr. Susanna Walter