Cerebral representation of the relief of itch by scratching
| Autor: | Clemens Forster, Hermann O. Handwerker, Miyuki Fukuoka, Akihiko Ikoma, Arnd Dörfler, Verena Vierow |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Adult
Male Time Factors Physiology Somatosensory system behavioral disciplines and activities Brain mapping Functional Laterality Premotor cortex Young Adult Behavior Therapy Cortex (anatomy) medicine Image Processing Computer-Assisted Cingulum (brain) Humans skin and connective tissue diseases Pain Measurement Cerebral Cortex Brain Mapping medicine.diagnostic_test General Neuroscience Putamen Pruritus Scratching Middle Aged Magnetic Resonance Imaging eye diseases Oxygen medicine.anatomical_structure nervous system Female Functional magnetic resonance imaging Psychology Neuroscience |
| Zdroj: | Journal of neurophysiology. 102(6) |
| ISSN: | 1522-1598 |
| Popis: | Cerebral processing of itch-scratching cycles was studied with functional magnetic resonance imaging (fMRI) in healthy volunteers. The back of the hand was repetitively scratched in the absence and presence of itch induced by histamine applied close to the scratched site. Blood-oxygenation-level-dependent (BOLD) effects were assessed in predefined cortical and subcortical brain regions of interest. Scratch-related activation clusters were found in cortical and subcortical areas which had been associated before with pain processing, namely S1, S2, parietal association cortex, motor and premotor cortex, anterior and posterior insula, anterior and medial cingulum, lateral and medial frontal areas, ipsilateral cerebellum and contralateral putamen. Cortical activations were generally stronger in the contralateral hemisphere. General linear model (GLM) analysis and GLM contrast analysis revealed stronger activations during itch-related trials in the motor and premotor cortex, in lateral frontal fields of both sides, and in a left medial frontal cluster. Subcortically, stronger activation during itch-related scratching trials was found in the contralateral putamen and in the ipsilateral cerebellum. Time course analysis showed significantly higher BOLD levels during the last 3–6 s before the start of scratching when the itch intensity was strongest. This effect was found in frontal areas, in the putamen, and in the somatosensory projection areas. During the scratching, no significant differences were found between itch and control conditions with the exception of the putamen, which showed stronger activations during itch-related scratch bouts. We interpret these itch-related activations anticipating the scratching as possible cerebral correlates of the itch processing and the craving for scratch. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|