Functional collumn of taste neurons in gustatory cortex in rats.

在之前的论文中，我们描述了机械感受神经元在大鼠初级味觉皮层（GC）中排列成一个功能柱（Wang and Ogawa,2002），并且柱直径的大小取决于感受特征。我们还注意到，味觉神经元也可能类似地分布在那里，这取决于四种基本味觉中最好的刺激。在本研究中，我们通过在大脑皮层表面以不同角度插入微电极，每隔50-100 μm记录神经元活动。我们还记录了味觉和机械感受神经元的感受特征（最佳刺激和感受野）。味觉神经元被记录在组织学重建的68个轨道中的49个。每条成功的轨迹平均遇到6.3个（范围在1-16个之间）味觉神经元。然而，在大多数轨道上，连续遇到了一个或两个味觉神经元，但在少数轨道上，碰巧连续遇到了5-6个味觉神经元。当连续记录两个或多个味觉神经元共享最佳刺激和感受野特性时，通过在皮层表面投影记录位置的宽度来测量柱状结构的大小，估计约为30 μm。该大小与相互相关分析估计的值一致（Nakamura和Ogawa，1997）。部分研究结果于2004年7月在日本京都举行的国际嗅觉和味觉研讨会上发表。

In the preceding paper, we described that mechanoreceptive neurons are arranged in a functional column in the primary gustatory cortex(GC) in rats(Wang and Ogawa,2002), and that the size of the columnar diameter varied depending on the receptive features. We also noted the evidence that gustatory neurons may similarly be arranged there, depending on the best stimulus among the four basic tastes. In the present study, we recorded neuronal activities every 50-100 μm by inserting microelectrodes to the cerebral cortex with various angles the cortical surface. We also characterized receptive features(best stimulus and receptive field) of taste and mechanoreceptive neurons recorded. Taste neurons were recorded at 49 of the 68 tracks histologically reconstructed. On average, 6.3(ranging 1-16) taste neurons were encountered every successful track. However, one or two taste neurons were successively encountered in most tracks, but 5-6 taste neurons happened to be encountered succesively in a few track. When two or more taste neurons sharing the best stimulus and receptive field properties in common were successively recorded, the columnar size was measured by projecting the width of the recording places on the cortical surfaces and was estimated about 30 μm. This size was compatible with the value estimated by cross-correlation analysis(Nakamura and Ogawa,1997). Parts of the results were presented to the International Symposium on Olfaction and Taste, held in Kyoto, Japan, in July,2004.