Papers of the Week

Itch is an unpleasant and aversive somatosensory experience. These negative emotions significantly affect mental health in chronic itch patients. Therefore, it is important to understand the brain mechanism of negative emotions due to itch. The amygdala is an important hub of network to regulate negative emotions due to itch. However, the exact network remains unknown. Thus, using functional magnetic resonance imaging, we investigated what network the amygdala constitutes for processing itch in human brains. Twenty-five healthy subjects participated in the present study. Brain activity during electrical itch stimuli was measured by using functional magnetic resonance imaging. The amygdala exhibited increased functional connectivity during itch stimuli with key brain regions of the serotonergic system responsible for negative emotions (the medial habenula, median raphe nucleus) and the memory system to consolidate emotional experiences (the parahippocampus, perirhinal cortex). These systems may become therapeutic targets to prevent or reduce diminished mental health commonly seen in chronic itch patients.