TASTE PSYCHOPHYSICS

产品说明：本研究的长期目标是了解味觉的遗传和病理变异对健康和生活质量的影响。人类在味觉上表现出遗传变异。这种变异的特征在于菌状乳头（容纳味蕾的结构）的数量和品尝PROP（6-n-丙基硫氧嘧啶）苦味的能力。因为菌状乳头接受来自味觉、疼痛和触觉神经元的神经支配，所以那些具有最多乳头的人（即，味觉超敏者）感知到更强烈的味道，口腔灼烧感（例如，辣椒）和口腔接触（例如，脂肪）的感觉。遗传味觉变异与对苦味食物的厌恶以及对甜味和远味食物的偏好有关（这包括水果和蔬菜，这些食物是心血管疾病和癌症的重要介质）。遗传性味觉变异也与酗酒和吸烟有关。涉及鼓索神经的病理与口腔幻痛（在没有刺激的情况下的感觉）有关;这些发生在味觉（味觉障碍）和口腔疼痛（灼口综合征）。评价的假设是鼓索神经（味觉，舌前部）通常抑制舌咽神经（味觉，舌后部）和三叉神经（疼痛，舌前部）。因此，对鼓索的损伤释放了这种抑制，导致味觉和疼痛感以及幻觉（例如，味觉障碍、灼口综合征）。易感个体似乎是那些具有味觉和疼痛神经支配的个体（即，超级味觉者）。该计划包括心理物理和解剖实验。一组实验将使用心理物理学方法和味觉解剖学的最新进展来确定非味觉者、中等味觉者和超级味觉者之间口腔感觉差异的大小。其他实验将测试对味觉和口腔灼伤的抑制的假设释放。正常志愿者的鼓索将被麻醉。患者将包括那些患有听神经瘤的患者，其中鼓索必须在其细胞体的中央被手术切断;神经将从切口退化到大脑中，可能导致中枢重组。患者还将包括乳突切除术或镫骨切除术的患者，其中鼓索必须在细胞体周围切断;神经将从切口退化到舌头，可能改变外周解剖结构。最后一组患者是那些有味觉和/或口腔疼痛幻觉的患者;他们将被评估可能对鼓索神经造成的损伤。

DESCRIPTION: (Author's Abstract) The long-term goal of this research is to understand the influence of genetic and pathological variation in taste sensations on health and quality of life. Humans show genetic variation in taste. This variation is characterized by the number of fungiform papillae (structures that house taste buds) and the ability to taste the bitterness of PROP (6-n-propylthiouracil). Because the fungiform papillae receive innervation from taste, pain, and touch neurons, those who have the highest number of papillae (i.e., supertasters) perceive more intense taste, oral burn (e.g., chilis) and oral touch (e.g., fat) sensations. Genetic taste variation is linked to distaste for bitter foods and preference for sweet and far foods (this includes fruits and vegetables, foods that are important mediators of cardiovascular disease and cancer). Genetic taste variation is also linked to alcoholism and smoking. Pathologies involving the chorda tympani nerve are linked to oral phantoms (sensations in the absence of stimulation); these occur for taste (dysgeusia) and oral pain (burning mouth syndrome). The hypothesis under evaluation is that the chorda tympani nerve (taste, anterior tongue) normally inhibits the glossopharyngeal nerve (taste, posterior tongue) and the trigeminal nerve (pain, anterior tongue). Damage to the chorda tympani thus releases that inhibition leading to intensified taste and pain sensations as well as phantoms (e.g., dysgeusia, burning mouth syndrome) in susceptible individuals. Susceptible individuals appear to be those who have the densest taste and pain innervation (i.e., supertasters). The proposal includes psychophysical and anatomical experiments. One group of experiments will use recent advances in psychophysical methodology and taste anatomy to determine the magnitude of oral sensory differences across nontasters, medium tasters and supertasters. Additional experiments will test the hypothesized release of inhibition on taste and oral burn. The chorda tympani will be anesthetized in normal volunteers. Patients will include those with acoustic neuromas in whom the chorda tympani must necessarily be surgically severed central to its cell bodies; the nerve will degenerate from the cut into the brain possibly leading to central reorganization. Patients will also include those with mastoidectomies or stapedectomies in whom the chorda tympani must necessarily be severed peripheral to the cell bodies; the nerve will degenerate from the cut into the tongue possibly altering peripheral anatomy. A final group of patients are those with taste and/or oral pain phantoms; they will be evaluated for possible damage to the chorda tympani nerve.