Norgren R
Am J Otolaryngol. 1983 Jul-Aug;4(4):234-7. doi: 10.1016/s0196-0709(83)80064-7.
Taste buds occur in five distinct populations in the mammalian oral cavity. The chemical sensitivity of these receptors varies from one population to another and among species as well. Taste buds degenerate when denervated and reappear when gustatory axons reinvade an area. Branches of three cranial nerves--VII, IX, and X--convey gustatory information to the medulla, where they terminate in the rostral two thirds of the nucleus of the solitary tract. Individual gustatory afferent fibers normally respond to several classes of sapid chemicals; they are broadly tuned. The tuning, however, is not random. For a given neuron, the best stimulus predicts the order of effectiveness of other stimulus qualities. Taste neurons in the first and second central relays, in the medualla and pons, respectively, are even more broadly tuned than those on the periphery but maintain a similar orderliness in the effectiveness of different sapid qualities. Much less is known about the response properties of taste neurons in more rostral areas. Even the basic anatomy of the gustatory system in the forebrain remains in question, because its organization differs in rodents and primates.
味蕾在哺乳动物口腔中以五种不同的群体形式存在。这些感受器的化学敏感性在不同群体之间以及不同物种之间都有所不同。味蕾在去神经支配后会退化，而当味觉轴突重新侵入一个区域时又会重新出现。三条颅神经（VII、IX和X）的分支将味觉信息传递到延髓，它们在孤束核的前三分之二处终止。单个味觉传入纤维通常对几类有味化学物质有反应；它们的调谐范围很广。然而，这种调谐并非随机的。对于给定的神经元，最佳刺激能预测其他刺激特性的有效性顺序。分别位于延髓和脑桥的第一和第二中枢中继站中的味觉神经元，其调谐范围比外周的味觉神经元更广，但在不同有味特性的有效性方面保持着相似的有序性。对于更靠前脑区的味觉神经元的反应特性了解得要少得多。甚至前脑味觉系统的基本解剖结构也仍存在疑问，因为其组织结构在啮齿动物和灵长类动物中有所不同。
