Psychophysical assessment of postgastric chemospecificinfluences on taste

描述（由申请人提供）：肥胖流行与过量摄入高热量、可口的食物和液体有关。口腔和口后化学信号整合在中枢神经系统中，以调整食物和液体选择，控制膳食大小，并建立口味偏好。然而，关于这些信号是如何被整合以改变摄入行为的，人们知之甚少。由于缺乏敏感的技术来探测口后化学感受信号并将其与摄入行为联系起来，这一进展受到了阻碍。最近，参与味觉传导的化学感受器和相关信号分子（例如，T1R，T2R，？在口后胃肠道细胞中发现了一种新的化学感受因子（-gustducin），这表明了一种有趣的可能性，即味觉特性是在上升的口后信号中编码的信息之一，并且可以直接访问和影响来自口腔的匹配化学感受信号。考虑到口腔和postoral感觉信号上升的中枢神经系统在大致平行的途径，这是特别令人惊讶的是，很少有实验注意到postoral信号对初级味觉感觉处理的直接影响。因此，存在一个共同的感觉系统提供了一个框架，探测化学特异性的影响，口后信号的特点，味道引导的行为。目前的建议寻求支持开始心理物理评估的化学特异性影响的口后信号味觉反应的大鼠模型。两种味觉特异性和互补的行为技术将用于评估十二指肠内化学输注对（a）享乐评价和（B）敏感性的影响，与刺激的享乐价无关，口腔味觉刺激。具体目标1测试的假设，即胃后信号影响享乐评价的口腔味觉刺激，在一个 在味觉反应性测试中以化学特异性方式。具体目标2测试的假设，胃后信号影响口腔味觉敏感性的化学特异性的方式在两个响应操作性味觉信号检测任务。应用这些心理物理学技术不仅可以识别新的、潜在的重要的初级感觉整合类型， 为我提供新的行为方法和数据分析方面的培训（例如，心理测量功能），并使我接触到一个以味觉功能为中心的概念专业知识的新领域。这种胃肠道味觉信号的心理物理测试，通过其对口腔味觉处理的具体影响，将指导未来的工作对潜在的神经机制，最终目标是确定潜在的目标和策略，以增加对控制食物摄入至关重要的感官反馈。

DESCRIPTION (provided by applicant): The obesity epidemic is associated with excessive intake of calorie dense, palatable foods and fluids. Oral and postoral chemical signals are integrated in the central nervous system to adjust food and fluid selection, control meal size, and establish taste preferences. Yet little is known about precisely how these signals are integrated to change intake behavior. Progress has been hampered by the lack of available sensitive techniques that probe postoral chemosensory signals and link those to intake behaviors. Recently, chemoreceptors and associated signaling molecules involved in taste transduction (e.g., T1Rs, T2Rs, ¿ -gustducin) have been discovered in postoral GI cells, suggesting the interesting possibility that taste properties are among the information encoded in ascending postoral signals and may directly access and impact matching chemosensory signals arising from the oral cavity. Considering oral and postoral sensory signals ascend the central nervous system in roughly parallel pathways, it is especially surprising then that very little experimental attention has been paid to direct influence of postoral signals on primary taste sensory processing. As such, the presence of a common sensory system provides a framework for probing chemospecific influences of postoral signals on well characterized taste-guided behaviors. The present proposal seeks support to begin the psychophysical assessment of chemospecific influences of postoral signals on taste responsiveness in a rat model. Two taste-specific, and complementary, behavioral techniques will be used to assess the effects of intraduodenal chemical infusions on (a) hedonic evaluation of and (b) sensitivity to, independent of the hedonic valence of the stimulus, an oral taste stimulus. Specific Aim 1 tests the hypothesis that postgastric signals influence the hedonic evaluation of an oral taste stimulus in a chemospecific manner in the taste reactivity test. Specific Aim 2 tests the hypothesis that postgastric signals influence oral taste sensitivity in a chemospecific manner in the two response operant taste signal detection task. Not only will applying these psychophysical techniques identify novel, and potentially, important types of primary sensory integration, it will afford me training in new behavioral approaches and data analyses (e.g., psychometric functions) and expose me to a new area of conceptual expertise centered on gustatory function. Such psychophysical testing of GI taste signals through their specific impact on oral taste processing will direct future work on the underlying neural mechanisms, with the ultimate goal of identifying potential targets and strategies to augment sensory feedback crucial to the control of food intake.