Parsons T D, Kleinfeld D, Raccuia-Behling F, Salzberg B M
Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia 19104.
Biophys J. 1989 Jul;56(1):213-21. doi: 10.1016/S0006-3495(89)82666-9.
We used multiple-site optical recording methods, in conjunction with impermeant molecular probes of the cell membrane potential, to record the electrical activity of model neural circuits in vitro. Our system consisted of co-cultured pairs of left upper quadrant neurons from the abdominal ganglion of the marine gastropod Aplysia. These neurons interact via inhibitory synapses in vitro. Photodynamic damage to the neurons was essentially eliminated over the time course of the measurements, approximately less than 30 s, by removing oxygen from the recording solution and replacing it with argon. This procedure did not affect the synaptic interactions. We observed repetitive spiking activity in single-trace optical recordings with a maximum signal-to-noise ratio per detector of approximately 50. Individual optical signals that corresponded to either the activity of the presynaptic neuron or that of the postsynaptic neuron were clearly identified. This allowed us to monitor the activity of synaptically interacting neurons, observed as a reduction of the firing rate of the postsynaptic cell after activity of the presynaptic cell. Our results demonstrate that optical methods are appropriate for recording prolonged, asynchronous activity from synaptically interacting neurons in culture.
我们使用多部位光学记录方法，结合细胞膜电位的非渗透性分子探针，来记录体外模型神经回路的电活动。我们的系统由海洋腹足纲动物海兔腹神经节左上象限神经元的共培养对组成。这些神经元在体外通过抑制性突触相互作用。通过从记录溶液中去除氧气并用氩气替代，在测量的时间过程中（约少于30秒）基本消除了对神经元的光动力损伤。该程序不影响突触相互作用。我们在单通道光学记录中观察到重复的尖峰活动，每个探测器的最大信噪比约为50。清晰地识别出对应于突触前神经元或突触后神经元活动的单个光学信号。这使我们能够监测突触相互作用神经元的活动，表现为突触前细胞活动后突触后细胞放电率的降低。我们的结果表明，光学方法适用于记录培养中突触相互作用神经元的长时间异步活动。
