臨床神経学

第51回日本神経学会総会

<シンポジウム18―1>辺縁系をめぐって
辺縁系と痛覚,痒み認知

柿木 隆介

自然科学研究機構生理学研究所統合生理研究系〔〒444―8585 愛知県岡崎市明大寺町字西郷中38〕
総合研究大学院大学生命科学研究科・生理科学専攻

Both electrophysiological studies such as magnetoencephalography (MEG) and hemodynamic studies such as functional magnetic resonance imaging (fMRI) are intensively being used to elucidate underlying mechanisms of human pain and itch perception. MEG following A-delta (first pain) and C fiber stimulation (second pain) were similar except for a longer latency for the latter. At first, primary somatosensory cortex (SI) contralateral to the stimulation is activated and then secondary somatosensory cortex (SII), insula, amygdala and anterior cingulate cortex (ACC) in the bilateral hemispheres are activated sequentially. As for findings using fMRI, the stimulation of both C and A-delta fibers activated the bilateral thalamus, bilateral SII, right (ipsilateral) middle insula, and bilateral Brodmann's area (BA) 24/32, with the majority of activity found in the posterior portion of the ACC. However, magnitude of activity in the BA32/8/6, including ACC and pre-supplementary motor area (pre-SMA), and the bilateral anterior insula was significantly stronger following the stimulation of C nociceptors than A-delta nociceptors. Findings following itch stimulation were similar to those following pain stimulation, but the precuneus may be itch selective brain region. This unique finding was confirmed by both MEG and fMRI studies.
Full Text of this Article in Japanese PDF (349K)

(臨床神経, 50:997−999, 2010)
key words:痛み,痒み,島皮質,帯状回,楔前部

(受付日:2010年5月22日)