MECHANICAL, THERMAL, AND OPTICAL SIGNS OF EXCITATION IN THE NERVOUS SYSTEM

在本财政年度，我们继续调查 神经组织中快速结构变化的性质 兴奋的过程。 去年，我们发现， 电鳐的发电器官，以其大量的胆碱能神经支配而闻名， 神经末梢释放的化学递质 突触后神经元迅速肿胀（水含量上升） 元素 我们已经证明，在本财政年度的早期， 年，这些机械变化伴随着大，容易 组织中可检测到的光学变化，即，由于一个明显的下降 接着是光散射的持续上升。 我们认为 突触后膜的钙离子释放 化学递质释放（Neuman等人，（1973-1976年） 这些机械和光学的变化。 后来，我们致力于 开发一种新型的热探测器， 聚脲膜（Takahashi等人，70;6983，1991）。 通过 由于脲基中的脲基所携带的大偶极矩， 聚合物，发现可以赋予这种膜强的 热电性 应我们的要求，筑波超级研究所 日本材料给我们发来热释电聚脲薄膜样品 （沉积在5微米厚的聚酯薄膜层上）。 热记录 射线电器官的变化，用我们现有的探测器获得 最近制造的，似乎表明热量产生的开始 与osnet大致同步（在0.5毫秒内 突触后电位

We have continued, during this fiscal year, our investigation into the nature of the rapid structural changes in the nervous tissues associated with the process of excitation. Last year, we found, employing the electric organ of the ray known for its massive cholinergic innervation, that the chemical transmitter released from the nerve endings evokes rapid swelling (a rise in the water content) in the postsynaptic elements. We have demonstrated, during the early period of this fiscal year, that these mechanical changes are accompanied by large, readily detectable optical changes in the tissues, i.e., by a pronounced fall followed by a sustained rise in light scattering. We believe that the release of Ca-ions from the postsynaptic membrane triggered by the chemical transmitter release (Neuman et al., 1973-1976) is at the base of these mechanical and optical changes. Later on, we devoted our effort to the development of a new type of heat detector by using extremely thin polyurea film (Takahashi et al., J. Appl. Phys. 70;6983, 1991). By virtue of the large dipole moment carried by the urea groups in the polymer, it was found possible to endow such film with strong pyroelectricity. Responding to our request, Tsukuba Institute for Super Materials in Japan sent us samples of pyroelectric polyurea film (deposited on five-micron thick mylar layer). The records of thermal changes in the ray electric organ, obtained with the detectors we have fabricated recently, appear to indicate that the onset of heat production by the tissue is roughly simultaneous (within 0.5 msec) with the osnet of the postsynaptic potential.