Neural circuitry underlying effects of context on human pain-related fear extinction in a renewal paradigm.

Objectives: The role of context in pain-related extinction learning remains poorly understood. We analyzed the neural mechanisms underlying context-dependent extinction and renewal in a clinically relevant model of conditioned abdominal pain-related fear.

Experimental Design: In this functional magnetic resonance imaging study, two groups of healthy volunteers underwent differential fear conditioning with painful rectal distensions as unconditioned stimuli (US) and visual conditioned stimuli (CS(+) ; CS(-) ).

Learning pain-related fear: neural mechanisms mediating rapid differential conditioning, extinction and reinstatement processes in human visceral pain.

Background And Aims: There exists converging evidence to support a role of pain-related fear in the pathophysiology and treatment of chronic pain conditions. Pain-related fear is shaped by associative learning and memory processes, which remain poorly characterized especially in the context of abdominal pain such as in irritable bowel syndrome (IBS). Therefore, using event-related functional magnetic resonance imaging (fMRI), we assessed the neural mechanisms mediating the formation, extinction and reinstatement of abdominal pain-related fear in healthy humans.

Towards understanding sex differences in visceral pain: enhanced reactivation of classically-conditioned fear in healthy women.

Sex differences in learned fear regarding aversive gastrointestinal stimuli could play a role in the female preponderance of chronic abdominal pain. In a fear conditioning model with rectal pain as unconditioned stimulus (US), we compared healthy males and females with respect to neural responses during aversive visceral learning, extinction and re-activation of fear memory (i.e.

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.

Cerebellar contributions to different phases of visceral aversive extinction learning.

The cerebellum is increasingly recognized to contribute to non-motor functions, including cognition and emotion. Although fear conditioning has been studied for elucidating the pathophysiology of anxiety, the putative role of the cerebellum is still unknown. Fear conditioning could also be important in the etiology of chronic abdominal pain which often overlaps with anxiety.

Fear conditioning in an abdominal pain model: neural responses during associative learning and extinction in healthy subjects.

Fear conditioning is relevant for elucidating the pathophysiology of anxiety, but may also be useful in the context of chronic pain syndromes which often overlap with anxiety. Thus far, no fear conditioning studies have employed aversive visceral stimuli from the lower gastrointestinal tract. Therefore, we implemented a fear conditioning paradigm to analyze the conditioned response to rectal pain stimuli using fMRI during associative learning, extinction and reinstatement.

Acute experimental endotoxemia induces visceral hypersensitivity and altered pain evaluation in healthy humans.

Growing evidence suggests that systemic immune activation plays a role in the pathophysiology of pain in functional bowel disorders. By implementing a randomized crossover study with an injection of endotoxin or saline, we aimed to test the hypothesis that endotoxin-induced systemic inflammation increases visceral pain sensitivity in humans. Eleven healthy men (mean ± standard error of the mean age 26.