DEVELOPMENT OF THE SENSE OF TASTE

在哺乳动物味觉系统的发育过程中， 与对照组相比， 其他盐。 盐味觉反应的发育差异是 伴随着神经重排， 第一和第二感受野的乳头和味蕾 舌头前部的味觉神经元 继续 神经生理学和神经解剖学研究的发展 提出了胚胎和出生后绵羊的盐味觉， 测试与感受野形成相关的想法， 味觉神经元的特征 为了了解是否有一个 高神经支配和随后纤维的发育期 消除菌状乳头，并伴有 味蕾的大小和数量，菌状乳头和味蕾 将对5个年龄组的绵羊进行检查， 切断三叉神经的舌分支。 数字 味蕾和乳头内神经纤维的数量将被确定。 味蕾形态也将进行研究。 核中 延髓孤束（NST），有索会聚 胎儿和出生后的第二级细胞的鼓膜传入 绵羊，所以感受野可以非常大， 趋同性在发展中增强。 然而即便是 广泛收敛，感受野大小之间的关系 并且咸味反应集中维持。 神经元 不同的反应和感受野特性可能是 在NST中以功能和/或形态 微观组织 为了验证这些想法，神经生理学 将从NST中的细胞群记录响应， 神经元的形态将由神经元的重建来确定。 HRP显微注射后的细胞。 接收场组织 后舌可能与上舌有很大不同 舌前部，因为大量的味蕾位于 相对较少的轮廓状乳头。 开始表征 舌后部感受野的数目、位置和盐 轮廓乳头和味蕾的味觉反应 单个舌咽神经纤维感受野和NST 细胞将被确定。 这些关于味觉感受的实验 场和神经元特征将有助于理解 盐的味觉，以及盐的味道如何发展和改变， 年龄函数。 盐的发育差异知识 味觉有助于理解 盐的偏好和摄入量在整个生命周期。

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.