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

我们继续并扩大了对非电气 神经系统兴奋过程的迹象。 使用 牛蛙和新生大鼠的分离脊髓制备物， 我们发现到达脊髓的传入神经冲动 引起脐带温度的快速上升。 的透彻 对观察到的温度升高的检查表明， 神经冲动通过突触的传递 感觉纤维的末端伴随着产生一个 胶状质中有大量的热量 这 脊髓“热反应”的发现 我们一个新的，有用的工具，研究各种影响， 化学物质对突触传递的影响 我们还研究 牛蛙视网膜的兴奋过程，通过使用我们的热 探测器和压电传感器。 我们发现 暗适应视网膜中的光感受器能够 释放的热能是太阳能的一百万倍 大到用于刺激的光脉冲的能量。 此外，我们发现可以分析 视网膜中的突触传递， 答案是一个指数。

We continued and expanded our investigation of non-electrical signs of excitation processes in the nervous system. Using isolated spinal cord preparations of the bullfrog and newborn rat, we found that afferent nerve impulses arriving at the spinal cord evoke a rapid rise in the temperature of the cord. A thorough examination of the observed temperature rise has indicated that transmission of nerve impulses across the synapses at the terminals of the sensory fibers is accompanied by generation of a considerable amount of heat in the substantia gelatinosa. This discovery of the "thermal response" of the spinal cord has given us a new, useful tool for studying the effects of various chemicals on synaptic transmission. We also examined excitation processes in the bullfrog retina by using our thermal detectors and piezoelectric sensors. We found that the photoreceptors in the dark-adapted retina are capable of releasing thermal energy which is more than one million times as large as the energy of the light pulse used for stimulation. Furthermore, we found it possible to analyze the processes of synaptic transmission in the retina by taking its mechanical responses as an index.