Sub-Threshold Receptive Fields of Sensory Neocortex

一种新的方法正在开发中，用于研究在清醒的哺乳动物大脑中单个神经元内发生的阈值下突触事件。与传统方法不同，传统方法需要细胞内微电极刺穿神经细胞并造成损害，本方法使用的是细胞外电极。因此，细胞损伤的结果要小得多，阈值以下的突触事件可以研究很长一段时间。该方法需要将细胞外电流脉冲通过记录微电极，并测量被研究神经元对这种直接电刺激的阈值。本研究探索了这种新方法在皮质神经生理学中的两个问题领域的应用：(1)分析新皮质感觉皮层的阈值下感受野和感受野的成分；(2)分析在很长一段时间内使用长期植入的电极研究神经元的阈值下突触输入。这项研究将有助于更好地理解感觉知觉的皮质神经元底物，以及长时间经验改变单个神经元特性的动态机制。

A novel method is being developed for study of sub-threshold synaptic events that occur within individual neurons in the awake mammalian brain. Unlike traditional methods which require impalement and resultant damage to a nerve cell by an intracellular microelectrode, the present method uses an electrode which is extracellular. Far less cellular damage results, therefore, and sub-threshold synaptic events can be studied for very long periods of time. The method entails passing extracellular current pulses through a recording microelectrode and measuring the threshold of the neuron under study to this direct electrical stimulation. This research explores the application of this new method to two problem areas in cortical neurophysiology: (1) the analysis of sub- threshold receptive fields and components of receptive fields in sensory neocortex, and (2) the analysis of sub-threshold synaptic inputs to neurons studied with chronically implanted electrodes over very long periods of time. This research will contribute to a better understanding of the cortical neuronal substrates of sensory perception and the dynamic mechanisms by which the properties of individual neurons are modified by experience over long periods of time.