TASTE PSYCHOPHYSICS

描述：(作者摘要)这项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。人类在口味上表现出遗传变异。这种变异的特征是菌状乳突(容纳味蕾的结构)的数量和品尝道具(6-正丙基硫氧嘧啶)的能力。因为菌状乳头接受味觉、疼痛和触觉神经元的神经支配，所以那些乳头数量最多的人(即味觉超级者)会感觉到更强烈的味道、口腔灼热(例如辣椒)和口腔触摸(例如脂肪)。基因的味道变化与厌恶苦味食物和偏爱甜食和远味食物(包括水果和蔬菜，这些食物是心血管疾病和癌症的重要媒介)有关。遗传的口味变化也与酗酒和吸烟有关。涉及鼓索神经的病理与口腔幻觉(在没有刺激的情况下的感觉)有关；这些幻觉发生的原因是味觉障碍和口腔疼痛(灼口综合征)。正在评估的假设是，鼓索神经(味觉，舌前)通常抑制舌咽神经(味觉，舌后)和三叉神经(痛，舌前)。因此，对鼓索的损伤会释放这种抑制，导致易感个体的味觉和痛觉以及幻觉(例如，动作障碍、灼口综合征)加剧。易受影响的人似乎是那些味觉和痛觉神经最密集的人(即味觉超级者)。该提案包括心理物理和解剖学实验。其中一组实验将使用心理物理学方法学和味觉解剖学的最新进展来确定非品尝者、中等品尝者和超级品尝者之间口腔感官差异的大小。其他实验将测试对味觉和口腔灼伤抑制的假想释放。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，在这些患者中，必须通过手术切断位于细胞体中央的鼓索；神经将从切入大脑的伤口退化，可能导致中枢重组。患者还将包括乳突切除或砧骨切除的患者，在这些患者中，鼓索必须被切断在细胞体的外围；神经将因切入舌头而退化，可能会改变周围的解剖结构。最后一组患者是那些有味觉和/或口腔疼痛幻影的人；他们将接受鼓索神经可能受损的评估。

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.