摂食調節と睡眠(シンポジウム : 心身機能と睡眠障害,2006年,第47回日本心身医学会総会(東京))  [in Japanese] Feeding Regulatoin and Sleep(Syumposium : Psychosomatic Function and Sleep Disorders)  [in Japanese]

中高年の肥満は睡眠障害の危険因子であり,小児の遅寝と睡眠減少は肥満の危険因子となる.日内リズムを制御している視交叉上核を破壊すると日内リズムの消失と肥満や種々の代謝異常が生じ,時計遺伝子の出演遺伝子の変異も日内リズムの異常と肥満・代謝異常を引き起こす.本研究では摂食や睡眠を司る身体システムが心機能に及ぼす影響に注目し,摂食と睡眠覚醒に関わる視床下部ペプチド・オレキシンやその他の摂食調節物質の高次脳機能に及ぼす影響を調べ,さらにコミュニケーション障害のほかに多彩な精神症状や自律機能障害を示す自閉症の睡眠リズムを解析することにより,心身相関の基本モデルを考察し,摂食-睡眠調節系と高次脳機能の機能連関を考察する.

Obesity and sleep disorder are mutual risk factors for each other. Late sleep onset and reduction of sleep have been shown to be risk factors of obesity in children. These symptoms with unstable wake onset are often seen in autistic children and well correlated with other mental problems. These findings suggest that feeding regulation and other brain functions including sleep-awake control and certain higher brain functions may share common control signaling. Lesion of suprachiasmatic nucleus in the hypothalamus induces not only disturbance of circadian rhythm but also obesity and metabolic dysfunctions. Lateral hypothalamic peptide orexin facilitates food intake and wakefulness but suppresses spatial memory and hippocampal long-term potentiation. In contrast, appetite-reducing substances such as glucose, cholecystokinin, leptin and 2-buten-4-olide facilitate spatial memory and hippocampal long-term potentiation. Sleep-awake cycles and feeding behavior are regulated by two physiological processes, homeostatic processes and circadian rhythm. We analyzed dynamical properties of irregular sleep-wake patterns of autistic children and revealed that the sleep-wake patterns of autistic children are under the control of the same deterministic rules of normal children with different parameter setting. Integrated analyses using mathematical model and molecular analyses may provide better understanding of the neural mechanisms of homeostatic problems in which many regulating factors are involved.