Optical recording of the synaptic functions of the frog lumbar sympathetic ganglia using voltage-sensitive dyes.

在从牛蛙解剖的腰交感神经节的制备中，通过使用电活动的多位点光学记录，用电压敏感的部花青-若丹宁染料（NK 2761）和多元件光电二极管阵列监测对电刺激的神经反应。去极化神经刺激引起的电压相关吸光度变化用抽吸电极同时记录了多个相邻位点的（正）方波电流脉冲，逆行刺激神经节细胞突触后轴突所诱发的光信号（刺激后），表现出一个相对简单的形状与尖锐的尖峰，其次是下冲，其可能分别反映神经节细胞的动作电位和后超极化。另一方面，由施加于突触前纤维的顺向刺激诱发的光信号（刺激前），也呈尖峰状，但形状更复杂，并且经常观察到双峰信号，提示突触前神经元和突触后神经元的成分在诱发的光信号中是叠加的。为了抑制突触传递，由预刺激诱发的光信号被连续地分离成突触前和突触后成分。光信号的突触前成分对突触传递的抑制具有抵抗性，并且被认为依赖于外部Ca ^<2 +>。

In the preparations of the lumbar sympathetic ganglion dissected from bullfrogs, the neural responses to electrical stimulation were monitored by using multiple-site optical recording of electrical activity,with a voltage- sensitive merocyanine-rhodanine dye (NK2761) and a multiple element photodiode array. Voltage-related absorbance changes evoked by nerve stimulation with depolarizing (positive) square current pulses using a suction electrode were recorded simultaneously from many contiguous loci in the preparation.The optical signals, evoked by the antidromic stimulation for the post- synaptic axons of the ganglion cells (post-stimulation), exhibited a relatively simple shape with a sharp spike followed by the undershoot, which is likely to reflect the action potential and the after-hyperpolarization of the ganglion cells respectively. On the other hand, the optical signals, evoked by orthodromic stimulation applied to the pre-synaptic fibers (pre-stimulation), were also spike-like but more complex in shape, and the double-peaked signals were often observed, suggesting that the component from pre-synaptic neurons and that from post-synaptic neurons were superimposed in the evoked optical signals.Using a low-Ca^<2+> Ringer solution or d-tubocurarine (d-Tc) to suppress the synaptic transmission, the optical signals evoked by pre-stimulation were successively separated into pre-synaptic and post-synaptic components. The pre- synaptic component of the optical signals was resistant to the suppression of the synaptic transmission, and was suggested to be dependent on the external Ca^<2+>.