Taste and Oral Sensory Processing in the Brain

描述(由申请人提供)：味觉关键指导进食决定，影响营养状况，并可能导致人类的健康问题，如肥胖、糖尿病和冠心病。因此，了解味觉的机制对于确定感官因素如何影响人类的健康和福祉至关重要。味觉体验通常与其他口感一致，如质地和温度(躯体感觉)。味觉可以被口腔温度改变，这表明味觉和体温感觉是联系在一起的。脑干中的味觉神经元对口腔温度做出反应，因此适合处理综合味觉和热输入。这项拟议研究的长期目标是确定脑干中多模式口头感觉加工的机制。使用麻醉的小鼠，将从对味觉和口腔热输入都敏感的单个脑干神经元进行电生理记录。具体目标#1将测试口腔温度影响味觉神经编码的假设。将记录和分析口腔对冷味和热味刺激的反应，以确定温度如何影响味觉质量和强度信息的神经表征。具体目标#2将检验这样一个假设，即味觉神经元对类似享乐性价态的味道和温度表现出类似的敏感性。这些项目将阐明味觉神经元发出口头躯体信息的能力，并暗示口腔感觉系统将被整合，而不是一组离散的形式。对不同味觉刺激以及无害和有害口腔温度的浓度系列的神经反应的分析将对这一想法进行评估。具体目标#3将检验这样一种假设，即在启动口腔感觉时，对味觉神经元的热输入在味觉之前传递。定时测序可能是温度和味觉之间相互作用的基础--快速的、早期的热刺激可以启动味觉网络，以调节随后的味觉输入。将分析单个神经元和神经集合的反应时间进程数据，以评估味觉和热相互作用是否取决于感觉输入的顺序。总体而言，这些项目将阐明可能涉及味道整合和摄食决定的多感官神经过程。

DESCRIPTION (provided by applicant): Taste critically guides ingestive decisions that impact nutritional status and can lead to health problems in humans, such as obesity, diabetes and coronary heart disease. Thus, understanding mechanisms for taste is critical for defining how sensory factors impact human health and well being. Taste experience typically occurs in unison with other oral sensations, such as texture and temperature (somatic sensations). Taste perceptions can be modified by oral temperature, indicating the mechanisms of taste and thermosensation are linked. Taste neurons in the brain stem respond to oral temperature and, thus, are suited to process integrated taste and thermal input. The long-term goal of the proposed research is to define mechanisms of multimodal oral sensory processing in the brain stem. Using anesthetized mice, electrophysiological recordings will be made from individual brain stem neurons sensitive to both taste and oral thermal inputs. Specific Aim #1 will test the hypothesis that oral temperature influences gustatory neural codes. Oral responses to cooled and warmed taste stimuli will be recorded and analyzed to define how temperature impacts neural representations of gustatory quality and intensity information. Specific Aim #2 will test the hypothesis that taste neurons show similar sensitivities to tastes and temperatures of similar hedonic valence. These projects will elucidate the ability of taste neurons to signal oral somatic information and have implications for the oral sensory system to be integrated and not a collection of discrete modalities. Analyses of neural responses to concentration series of hedonically different taste stimuli and innocuous and noxious oral temperatures will evaluate this idea. Specific Aim #3 will test the hypothesis that upon initiating oral sensation thermal input to taste neurons is transmitted before taste. Timed sequencing may underlie interactions between temperature and taste - fast, early thermal stimulation could prime taste networks for modulation of subsequent taste input. Response time course data for individual neurons and neural ensembles will be analyzed to evaluate if taste and thermal interactions depend on the sequencing of sensory input. Overall, these projects will shed light on multisensory neural processes potentially involved in aspects of flavor integration and ingestive decisions.