過敏性腸症候群における脳腸相関(シンポジウム:脳科学による心身症の解明,2008年,第49回日本心身医学会総会(札幌))  [in Japanese] Brain-Gut Interactions in Irritable Bowel Syndrome(Symposium/Psychosomatic Disorders as Revealed by Brain Science)  [in Japanese]

心身症とは,心理社会的ストレスにより,器質的病変あるいは機能的異常を呈する身体疾患である.その病態生理は自律神経・内分泌系を中心に研究されてきた.しかし,過敏性腸症候群を代表格とする心身症の脳機能を明らかにすることで,情動の形成機序をも明らかにしうる可能性が出てきている.内臓への侵害刺激は前帯状回,扁桃体,島などを活性化する.この中でも前帯状回と扁桃体の活性化は,それぞれうつと不安の病態で報告されているものであり,内臓痛と陰性情動が生成する共通の機序があるものと考えられる.われわれが情動と呼ぶ脳機能の大半は各感覚器官から入力された信号が脳内で処理され,嗅覚,視覚,聴覚,味覚,身体感覚の五感を統合することで成立する.身体感覚,特に,内臓感覚に代表される内的感覚(interoception)の重要性は今後さらに増すであろう.

Psychosomatic disorders are the states with physical disorders, which are either organic or functional and originated from and/or aggravated by psychosocial stressors. The pathophysiology of psychosomatic disorders has been investigated mainly on autonomic nervous system and endocrine system. Recent advances in neuroscience enabled us to explore the brain mechanism of these disorders and emotion formation and typical example is irritable bowel syndrome. Noxious stimulation to the gut activates the anterior cingulate cortex, amygdala, insula, and so on. The activation of the anterior cingulate cortex is known to relate to depression, whereas the activation of the amygdala results in anxiety. Therefore, the common pathway between formation of visceral pain and that of negative emotion is suggested. Emotion is originated from the signal given to the peripheral sensory organs and initially it is perceived as olfaction, vision, audition, taste, and bodily sensation in the brain. Among these, role of bodily sensation whose prototype is visceral perception (interoception) in emotion formation will be clarified in the future.