Disease-specific alterations in central fear network engagement during acquisition and extinction of conditioned interoceptive fear in inflammatory bowel disease.

Interoceptive fear, which is shaped by associative threat learning and memory processes, plays a central role in abnormal interoception and psychiatric comorbidity in conditions of the gut-brain axis. Although animal and human studies support that acute inflammation induces brain alterations in the central fear network, mechanistic knowledge in patients with chronic inflammatory conditions remains sparse. We implemented a translational fear conditioning paradigm to elucidate central fear network reactivity in patients with quiescent inflammatory bowel disease (IBD), compared to patients with irritable bowel syndrome (IBS) and healthy controls (HC).

Amplified gut feelings under inflammation and depressed mood: A randomized fMRI trial on interoceptive pain in healthy volunteers.

Background: Inflammation and depressed mood constitute clinically relevant vulnerability factors for enhanced interoceptive sensitivity and chronic visceral pain, but their putative interaction remains untested in human mechanistic studies. We tested interaction effects of acute systemic inflammation and sad mood on the expectation and experience of visceral pain by combining experimental endotoxemia with a mood induction paradigm.

Methods: The double-blind, placebo-controlled, balanced crossover fMRI-trial in N = 39 healthy male and female volunteers involved 2 study days with either intravenous administration of low-dose lipopolysaccharide (LPS, 0.

Distinct Alterations in Central Pain Processing of Visceral and Somatic Pain in Quiescent Ulcerative Colitis Compared to Irritable Bowel Syndrome and Health.

Background And Aims: Despite relevance to pain chronicity, disease burden, and treatment, mechanisms of pain perception for different types of acute pain remain incompletely understood in patients with inflammatory bowel disease [IBD]. Building on experimental research across pain modalities, we herein addressed behavioural and neural correlates of visceral versus somatic pain processing in women with quiescent ulcerative colitis [UC] compared to irritable bowel syndrome [IBS] as a patient control group and healthy women [HC].

Methods: Thresholds for visceral and somatic pain were assessed with rectal distensions and cutaneous thermal pain, respectively.

Inflammation shapes neural processing of interoceptive fear predictors during extinction learning in healthy humans.

Inflammation could impact on the formation and persistence of interoceptive fear and hypervigilance, with relevance to psychiatric disorders and chronic pain. To systematically analyze effects of inflammation on fear learning and extinction, we performed two complementary randomized, double-blind, placebo-controlled functional magnetic resonance imaging (fMRI) studies combining experimental endotoxemia as a translational model of acute systemic inflammation with a two-day multiple-threat fear conditioning paradigm involving interoceptive and exteroceptive unconditioned stimuli (US). Healthy volunteers (N = 95) were randomized to receive intravenous injections of either endotoxin (lipopolysaccharide, LPS; 0.

Positive Treatment Expectations Shape Perceived Medication Efficacy in a Translational Placebo Paradigm for the Gut-Brain Axis.

Placebo research has established the pivotal role of treatment expectations in shaping symptom experience and patient-reported treatment outcomes. Perceived treatment efficacy constitutes a relevant yet understudied aspect, especially in the context of the gut-brain axis with visceral pain as key symptom. Using a clinically relevant experimental model of visceral pain, we elucidated effects of pre-treatment expectations on post-treatment perceived treatment efficacy as an indicator of treatment satisfaction in a translational placebo intervention.

Altered Brain Structure in Chronic Visceral Pain: Specific Differences in Gray Matter Volume and Associations With Visceral Symptoms and Chronic Stress.

Structural brain alterations in chronic pain conditions remain incompletely understood, especially in chronic visceral pain. Patients with chronic-inflammatory or functional bowel disorders experience recurring abdominal pain in concert with other gastrointestinal symptoms, such as altered bowel habits, which are often exacerbated by stress. Despite growing interest in the gut-brain axis and its underlying neural mechanisms in health and disease, abnormal brain morphology and possible associations with visceral symptom severity and chronic stress remain unclear.

When gut feelings teach the brain to fear pain: Context-dependent activation of the central fear network in a novel interoceptive conditioning paradigm.

The relevance of contextual factors in shaping neural mechanisms underlying visceral pain-related fear learning remains elusive. However, benign interoceptive sensations, which shape patients' clinical reality, may context-dependently become conditioned predictors of impending visceral pain. In a novel context-dependent interoceptive conditioning paradigm, we elucidated the putative role of the central fear network in the acquisition and extinction of pain-related fear induced by interoceptive cues and pain-predictive contexts.

Associative learning and extinction of conditioned threat predictors across sensory modalities.

The formation and persistence of negative pain-related expectations by classical conditioning remain incompletely understood. We elucidated behavioural and neural correlates involved in the acquisition and extinction of negative expectations towards different threats across sensory modalities. In two complementary functional magnetic resonance imaging studies in healthy humans, differential conditioning paradigms combined interoceptive visceral pain with somatic pain (study 1) and aversive tone (study 2) as exteroceptive threats.

Polarity-specific modulation of pain processing by transcranial direct current stimulation - a blinded longitudinal fMRI study.

Background: To enrich the hitherto insufficient understanding regarding the mechanisms of action of transcranial direct current stimulation (tDCS) in pain disorders, we investigated its modulating effects on cerebral pain processing using functional magnetic resonance imaging (fMRI).

Methods: Thirteen right-handed healthy participants received 20 min of 1.5 mA tDCS applied over the primary motor cortex thrice and under three different stimulation pattern (1.

Greater fear of visceral pain contributes to differences between visceral and somatic pain in healthy women.

This functional magnetic resonance imaging study addressed similarities and differences in behavioral and neural responses to experimental visceral compared with somatic pain stimuli and explored the contribution of fear of pain to differences between pain modalities. In N = 22 healthy women, we assessed blood oxygen level-dependent responses to rectal distensions and cutaneous heat stimuli matched for perceived pain intensity. Fear of pain and pain unpleasantness were assessed before and after scanning.

Short Latency Gray Matter Changes in Voxel-Based Morphometry following High Frequent Visual Stimulation.

Magnetic resonance imaging studies using voxel-based morphometry (VBM) detected structural changes in the human brain within periods of months or weeks. The underlying molecular mechanisms of VBM findings remain unresolved. We showed that simple visual stimulation by an alternating checkerboard leads to instant, short-lasting alterations of the primary and secondary visual cortex detected by VBM.

Acupuncture-related modulation of pain-associated brain networks during electrical pain stimulation: a functional magnetic resonance imaging study.

Objective: Findings of existing functional MRI (fMRI) studies on the neural mechanisms that mediate effects of acupuncture analgesia are inconsistent. This study analyzes the effects of manual acupuncture on pain ratings and brain activation in response to experimental, electrical pain stimuli.

Design: Fourteen healthy volunteers were examined by using a 1.

Cortical plasticity in episodic and chronic cluster headache.

Cluster headache (CH) is characterized by recurrent episodes of excruciatingly painful, unilateral headache attacks typically accompanied by trigeminal autonomic symptoms. Due to its rhythm with alternating episodes of pain and no-pain, it is an excellent model to investigate whether structural brain changes detected by magnetic resonance based voxel-based-morphometry (VBM) reflect the cause of the disease, may be a consequence of the underlying disease other than pain, or may simply be caused by the sensation of pain itself. We investigated 91 patients with CH in different stages of their disease using VBM and compared them to 78 age- and gender-matched healthy controls.

Placebo analgesia in patients with functional and organic abdominal pain: a fMRI study in IBS, UC and healthy volunteers.

Objective: Understanding the neural circuitry of placebo analgesia in the context of visceral pain is increasingly important given evidence of clinical benefit of placebo treatment in IBS. This functional MRI study addressed placebo analgesia in IBS, UC and healthy control (HC) volunteers.

Design: Painful rectal distensions were delivered in N=17 patients with IBS , N=15 patients with UC in remission, and sex-matched and age-matched HCs in an adaptation phase followed by intravenous application of saline combined with either positive instructions of pain relief (placebo) or neutral instructions (control).

Central vestibular system modulation in vestibular migraine.

Background: Vestibular migraine affects 1% of the general population, and 30%-50% of all migraine patients describe occasionally associated vertigo or dizziness. We aimed to identify brain regions altered in vestibular migraine in order to evaluate the connection between migraine and the vestibular system.

Methods: Seventeen patients with definite vestibular migraine were compared to 17 controls using magnetic resonance imaging-based voxel-based morphometry.

Visceral sensitivity correlates with decreased regional gray matter volume in healthy volunteers: a voxel-based morphometry study.

Regional changes in brain structure have been reported in patients with altered visceral sensitivity and chronic abdominal pain, such as in irritable bowel syndrome. It remains unknown whether structural brain changes are associated with visceral sensitivity. Therefore, we present the first study in healthy individuals to address whether interindividual variations in gray matter volume (GMV) in pain-relevant regions correlate with visceral sensitivity.

Functional segregation in the left premotor cortex in language processing: evidence from fMRI.

Functional segregation has been revealed in the premotor cortex (PMC) and is related to motor and sensorimotor behaviors. Few data is available concerning the existence of similar segregation in the PMC during language processing. Here we correlated the roles of subregions of the left PMC in picture naming and articulation using functional magnetic resonance imaging (fMRI) and covert and overt picture naming in healthy volunteers.

Neural mechanisms mediating positive and negative treatment expectations in visceral pain: a functional magnetic resonance imaging study on placebo and nocebo effects in healthy volunteers.

To elucidate placebo and nocebo effects in visceral pain, we conducted a functional magnetic resonance imaging (fMRI) study to analyze effects of positive and negative treatment expectations in a rectal pain model. In 36 healthy volunteers, painful rectal distensions were delivered after intravenous application of an inert substance combined with either positive instructions of pain relief (placebo group) or negative instructions of pain increase (nocebo group), each compared to neutral instructions. Neural activation during cued-pain anticipation and pain was analyzed along with expected and perceived pain intensity.

Memory-related hippocampal activity can be measured robustly using FMRI at 7 tesla.

High field strength functional magnetic resonance imaging (fMRI) has developed rapidly. However, it suffers from increased artifacts in brain regions such as the medial temporal lobe (MTL), challenging functional imaging of the hippocampus with the objective of high-spatial resolution, which is particularly useful for this region both from a clinical and cognitive neuroscience perspective. We set out to compare a BOLD sequence at 7 T versus 3 T to visualize the MTL activity during an associative memory-encoding task.