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

在牛蛙腰交感神经节的制备过程中，采用多点电活动光学记录技术，采用电压敏感型花青红-罗丹宁染料(NK2761)和多元光电二极管阵列监测电刺激的神经反应。在制备过程中，用正方电流脉冲同时记录了多个相邻部位的电压相关吸光度变化。逆行刺激(刺激后)神经节细胞突触后轴突诱发的光信号形状相对简单，先是尖峰，然后是下射，这可能分别反映了神经节细胞的动作电位和后超极化。另一方面，顺向刺激作用于突触前纤维的光信号也呈尖峰状，但形状较复杂，常出现双峰信号，提示来自突触前神经元和突触后神经元的光信号叠加在光信号中。光信号的突触前成分对突触传递的抑制有抵抗作用，提示其依赖于外源性钙离子。

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+>.