DEVELOPMENT OF THE SENSE OF TASTE

在哺乳动物味觉系统的发育过程中，有一个 与生理盐水相比，神经反应性显著增加 其他盐类。盐味反应的发育差异是 伴随着改变真菌样细胞数量的神经重排 第一和第二感受野中的乳头和味蕾 对舌前部的味觉神经元进行排序。继续 发育的神经生理学和神经解剖学研究 提出了绵羊胚胎和出生后对盐味的感觉， 测试与接受场的形成和相关的想法 味觉神经元的特征。要了解是否存在 超神经支配和后续纤维的发育期 菌状乳头消失，并伴有相关的 味蕾的大小和数量，菌状乳头和味蕾 来自五个年龄段的绵羊将被检查后，同侧 三叉神经舌侧支横断术。数字 乳突内的味蕾和神经纤维的数量将被确定。 味蕾的形态也将被研究。在核心区 孤束(NST)在延髓内，有脊索汇聚 胎儿和出生后鼓膜向二级细胞的传入 绵羊，所以接受场可以很大，而且程度 趋同会在发展中增加。然而，即使有了 广泛收敛，感受野大小之间的关系 而盐味反应是集中维持的。神经元与 不同的响应和接受字段属性可能是 在功能和/或形态上聚集在NST中 微观组织。为了测试这些想法，神经生理学 将记录NST和NST中的细胞集群的响应 神经元的形态将通过重建 HRP显微注射后的细胞。接受型田野组织 后舌与后舌可能有很大的不同 舌头前部，因为有大量的味蕾位于 环状乳突相对较少。开始描述…的特征 舌后叶感受区的数目、位置和盐度 豚鼠环状乳突和味蕾的味觉反应 单根舌咽神经纤维和NST的感受野 牢房将被确定。这些关于味觉接受性的实验 领域和神经元的特征将有助于理解 盐味感觉，以及盐味是如何发展和变化的 年龄的作用。对盐的发育差异的认识 味觉有助于理解变化的模式 整个生命周期的盐分偏好和摄入量。

During development of the taste system in mammals, there is a striking increase in neural responsiveness to NaCl compared to other salts. Developmental differences in salt taste responses are accompanied by neural rearrangements that alter number of fungiform papillae and taste buds in receptive fields of first and second order taste neurons on the anterior tongue. Continuing neurophysiological and neuroanatomical studies of the development of salt taste sensation in fetal and postnatal sheep are proposed, to test ideas related to formation of receptive fields and related characteristics of taste neurons. To learn whether there is a developmental period of hyperinnervation and subsequent fiber elimination in fungiform papillae, with associated alterations in taste bud size and number, the fungiform papillae and taste buds from sheep in five age groups will be examined, after ipsilateral transection of the lingual branch of the trigeminal nerve. Numbers of taste buds and nerve fibers within papillae will be determined. Taste bud morphology also will be studied. In the nucleus of the solitary tract (NST) in the medulla, there is convergence of chorda tympani afferents onto second order cells in fetal and postnatal sheep, so receptive fields can be very large, and the degree of convergence increases developmentally. However, even with extensive convergence, the relation between receptive field size and salt taste responses is maintained centrally. Neurons with different response and receptive field properties might be clustered in the NST in a functional and/or morphological microorganization. To test these ideas, neurophysiological responses will be recorded from clusters of cells in NST and the morphology of neurons will be determined from reconstructions of cells after HRP microinjections. Receptive field organization on the posterior tongue is probably very different from that on anterior tongue because large numbers of taste buds are located in relatively few circumvallate papillae. To begin to characterize receptive fields on posterior tongue, the number, location and salt taste responses of circumvallate papillae and taste buds in receptive fields of single glossopharyngeal nerve fibers and NST cells will be determined. These experiments on taste receptive field and neuron characteristics will contribute to understanding salt taste sensation, and how salt taste develops and alters as a function of age. Knowledge of developmental differences in salt taste sensation contributes to understanding changing patterns of salt preference and intake throughout the life cycle.