Role of Fluctuations in Biological Signal Transmission.

(1)生物信号的编码机制及其对外界刺激及其波动的自我保护作用；(2)生物信息传递中包含的波动对感知、认知、判断和记忆的作用。这两个项目是本研究的主要研究对象。这些课题在三年的研究中还没有完全完成，但经过四次会议，取得了显著的进展。成果的详细情况载于最后报告。我们已经在细菌的身体运动、心率、头皮和脑细胞观察到的大脑信号的连贯性等方面发现了各种积极的波动现象。细胞膜自发放电间期的波动和自组织的意义已经从不同的角度进行了讨论。从统计力学的角度讨论了蛋白质分子的相变和非平衡开放系统的动力学。关于非平衡开放系统的时间可逆性、平稳性和详细平衡的主题被发现是理解生物现象的非常重要的概念。总之，从物理角度对生物功能的各种问题进行了讨论，并期望在未来朝着本研究的最终目标取得进一步的进展。

(1) Mechanism of coding of biological signals and its role in self-protection against external stimulations and its fluctuations, and (2) the function of fluctuations contained in biological information transmission in relation to perception, cognition, judgment and memory. These two items are main targets of the present research. These subjects of research have not fully accomplished during the 3-year research, but remarkable progress has been achieved toward them through four meetings we had. The details of the achievements are given in the final report. We have found various positive phases of fluctuation phenomena in bodily motion of bacteria, heart rate, coherence of brain signals observed on the scalp and in brain cells. Meanings of fluctuations in spontaneous discharge intervals of cell membranes and in self-organization have been discussed from various respects. Phase transition of protein molecules and dynamics of nonequilibrium open systems were discussed from a statistical mechanical point of view. Topics on time reversibility, stationarity, and detailed balance of the nonequilibrium open system were found to be very important concepts in understanding biological phenomenon. Conclusively, a variety of problems have been discussed on biological functions from a physical point of view and a further progress is expected toward the final goal of the present research in the future.