Ogawa H, Murayama N, Hasegawa K
Department of Physiology, Kumamoto University Medical School, Japan.
Exp Brain Res. 1992;91(3):408-14. doi: 10.1007/BF00227837.
Receptive fields (RFs) of 59 cortical taste neurons (35 in the granular insular area, area GI, 21 in the dysgranular insular area, area DI, and 3 in the agranular insular area, area AI) were identified in the oral cavity of the rat. The fraction of the neurons with RFs in the anterior oral cavity only was significantly larger in area GI (74.3%) than in area DI (42.9%). On the other hand, the fraction of neurons with RFs in both the anterior and posterior oral cavity was larger in area DI (42.9%) than in area GI (11.4%). On the whole, it is suggested that area GI is involved in discrimination of several taste stimuli in the oral cavity, whereas in area DI taste information originating from various regions of the oral cavity is integrated. When neurons were classified according to the best stimulus which most excited the neuron among the four basic tastes, different categories of taste neurons had RFs in different parts of the oral cavity. It is suggested that, in either taste area, different categories of taste neurons are involved in different sorts of taste coding. The majority of neurons in both areas had bilateral RFs. In area GI, neurons with RFs on single subpopulations of taste buds were significantly more numerous at the rostral region of the cortex than at the caudal region. There was no such relation between RF types and cortical localization in area DI. Otherwise, topographic representation of the oral cavity by taste neurons on the cortical surface was not obvious. RF features of taste neurons did not differ across layers in either cortical area.
在大鼠口腔中识别出59个皮质味觉神经元的感受野（RF）（颗粒状岛叶区域即GI区有35个，颗粒减少的岛叶区域即DI区有21个，无颗粒岛叶区域即AI区有3个）。仅在前口腔有感受野的神经元比例在GI区（74.3%）显著高于DI区（42.9%）。另一方面，在前口腔和后口腔都有感受野的神经元比例在DI区（42.9%）高于GI区（11.4%）。总体而言，提示GI区参与口腔中几种味觉刺激的辨别，而DI区整合来自口腔不同区域的味觉信息。当根据四种基本味觉中最能兴奋神经元的最佳刺激对神经元进行分类时，不同类别的味觉神经元在口腔的不同部位有感受野。提示在任何一个味觉区域，不同类别的味觉神经元参与不同类型的味觉编码。两个区域中的大多数神经元都有双侧感受野。在GI区，在味蕾单个亚群上有感受野的神经元在皮质的 Rostral 区域比在尾侧区域明显更多。在DI区，感受野类型与皮质定位之间没有这种关系。此外，味觉神经元在皮质表面对口腔的地形学表征并不明显。在任何一个皮质区域，味觉神经元的感受野特征在各层之间没有差异。
