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Highlights • IBS and Ulcerative Colitis (UC) patients have changes in brain network organization. • Changes in brain network organization correlate with disease symptomatology. • In UC, brain network organization changes correlate with disease duration. • Chronic gut inflammation as well as pain have neuroplastic effects on the brain., Objective We aimed to identify differences in network properties of white matter microstructure between asymptomatic ulcerative colitis (UC) participants who had a history of chronic gut inflammation, healthy controls (HCs) and a disease control group without gut inflammation (irritable bowel syndrome; IBS). Design Diffusion weighted imaging was conducted in age and sex-matched participants with UC, IBS, and HCs (N = 74 each), together with measures of gastrointestinal and psychological symptom severity. Using streamline connectivity matrices and graph theory, we aimed to quantify group differences in brain network connectivity. Regions showing group connectivity differences were correlated with measures showing group behavioral and clinical differences. Results UC participants exhibited greater centrality in regions of the somatosensory network and default mode network, but lower centrality in the posterior insula and globus pallidus compared to HCs (q

Highlights • Left anodal galvanic vestibular stimulation increased tactile sensitivity. • No effects induced by sham stimulation or right anodal galvanic vestibular stimulation. • Even brief (100 ms) pulses of vestibular stimulation enhanced somatosensory detection. • Vestibular projections in the right hemisphere modulates somatosensory processing., The vestibular system has widespread interactions with other sensory modalities. Here we investigate whether vestibular stimulation modulates somatosensory function, by assessing the ability to detect faint tactile stimuli to the fingertips of the left and right hand with or without galvanic vestibular stimulation (GVS). We found that left anodal and right cathodal GVS, significantly enhanced sensitivity to mild shocks on either hand, without affecting response bias. There was no such effect with either right anodal and left cathodal GVS or sham stimulation. Further, the enhancement of somatosensory sensitivity following GVS does not strongly depend on the duration of GVS, or the interval between GVS and tactile stimulation. Vestibular inputs reach the somatosensory cortex, increasing the sensitivity of perceptual circuitry.