Neural Taste an Thermal Coding in Geniculate Ganglion

味觉是一个重要的感官系统， 将环境中潜在的食物分为有益的营养素类别， 摄入，不需要的物品，以及要避免的毒素。有一个广泛 来自各种物种的研究文献集中在获得 了解味道是如何能够完成这一惊人的壮举， 生物体的健康和福利。越来越多的证据表明 这表明味觉系统可能可以分为少量的 子模态（例如，对于碳水化合物等是甜），虽然确切的数字 等待进一步调查。此外，一套独特的受体机制 和一组神经元，负责将信息传递到 大脑可以服务于每个子模态。我们的总体目标是利用细胞外 单细胞记录技术，以定义子模态的数量， 味觉系统，并表征其受体和神经反应 特性.我们最近开发了一种新的制剂， 记录味觉神经元的反应。我们建议的录音研究将是 面部神经的膝状神经节在神经节内， 单极细胞体的神经元，支配味觉受体上的 舌头和上颚我们建议表征化学和热 大鼠膝状体神经节对舌和腭刺激的敏感性， 并检查特定药理学拮抗剂对味觉的影响 转导机制老鼠将被研究，因为巨大的背景， 神经和行为研究主要来自大鼠，这是一个很好的 人类摄入的模式，我们对这个物种有丰富的经验。 本建议的具体目标是：（1）确定下列人员的反应特点： 盐敏感神经元和甜敏感神经元对各种刺激的反应 几种刺激浓度;（2）检查特定的 盐和甜味转导机制的药理学拮抗剂;（3） 表征各种神经元群对热刺激的反应， 评估味觉-热相互作用;以及（4）确定脂肪和 蛋白质可以包括在传统上限于甜味的主要味道中， 咸的、酸的、苦的。

Taste is a critical sensory system for sorting the rich array of potential foods in the environment into beneficial nutrient categories to be ingested, items not needed, and toxins to be avoided. There is an extensive research literature from a variety of species focused on gaining an understanding on how taste is capable of accomplishing this amazing feat for the health and welfare of the organism. There is a growing body of evidence that suggests that the gustatory system may be divisible into a small number of sub-modalities (e.g., sweet for carbohydrate, etc.), although the exact number awaits additional investigation. Further, a unique set of receptor mechanisms and group of neurons that are responsible for transmitting the information to the brain may serve each sub-modality. Our overall goal is to use extracellular single-cell recording techniques to define the number of sub modalities in the gustatory system and characterize their receptor and neural response properties. We have recently developed a new preparation for stable long-term recording of taste neuron responses. Our proposed recording studies will be from the geniculate ganglion of the facial nerve. Within the ganglion are the unipolar cell bodies of neurons that innervate the taste receptors on the tongue and palate. We propose to characterize the chemical and thermal sensitivity of the rat geniculate ganglion to lingual and palatal stimulation, and to examine the effects of specific pharmacological antagonists on taste transduction mechanisms. The rat will be studied because the vast background of neural and behavioral research comes largely from rats, it is an excellent model of human ingestion, and we have extensive experience with this species. The specific aims of this proposal are: (1) to characterize the responses of salt-sensitive and sweetsensitive neurons to a broad array of stimuli across several stimulus concentrations; (2) to examine the effects of specific pharmacological antagonists on salt and sweet transduction mechanisms; (3) to characterize the responses of various neuron groups to thermal stimulation and to assess taste-thermal interaction; and (4) to determine whether fat and protein can be included into primary taste traditionally restricted to sweet, salt, sour, and bitter.