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

我们继续并扩大了我们对非电气产品的研究 神经系统中有兴奋过程的迹象。vbl.使用 牛蛙和新生大鼠的分离脊髓标本， 我们发现到达脊髓的传入神经冲动 会引起脐带温度的快速上升。一次彻底的 对观测到的温度上升的检查表明 神经冲动在突触上的传递 感觉纤维的终末伴随着一种 胶状质中有相当多的热量。这 脊髓“热反应”的发现给出了 美国是一种新的有用的工具，用于研究各种 影响突触传递的化学物质。我们还检查了 利用我们的热刺激刺激牛蛙视网膜的过程 探测器和压电式传感器。我们发现， 暗适应视网膜中的光感受器能够 释放的热能是地球能量的一百多万倍 与用于刺激的光脉冲的能量一样大。 此外，我们发现有可能分析 视网膜中的突触传递通过其机械的 将回复作为索引。

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.