Effects of expectation on gustatory cortex activity

期望对味觉皮层活动的影响

• 批准号: 7262198
• 负责人: Alfredo Fontanini
• 金额: $ 7.7万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-07 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7262198
• 关键词: Address; Amygdaloid structure; Animals; Area; Attention; Auditory; Behavioral; Bilateral; Brain; Cannulas; Cells; Code; Cognitive; Comprehension; Condition; Correlation Studies; Cues; Discrimination; Eating Disorders; Electrodes; Electromyography; Electrophysiology (science); Evaluation; Food; Food Selections; Generic Drugs; Hand; Human; Implant; Implanted Electrodes; Light; Mammals; Masticatory muscles; Mental Processes; Nature; Neurons; Neurosciences; Obesity; Oral; Outcome; Perception; Performance; Placebo Effect; Placebos; Play; Process; Public Health; Quinine; Rattus; Reaction Time; Rewards; Rodent; Role; Role playing therapy; Self Administration; Self-Administered; Sensory; Shapes; Signal Transduction; Smell Perception; Source; Specificity; Stimulus; Sucrose; Suggestion; System; Taste Perception; Testing; Thinking; Training; Work; awake; base; design; expectation; insight; interest; neural circuit; neuromechanism; physical property; receptive field; relating to nervous system; research study; response; sensory neuroscience; sensory stimulus; sensory system; theories

DESCRIPTION (provided by applicant): The brain processes sensory stimuli differently depending on whether an animal is awake or anesthetized. In anesthetized animals no internal cognitive activity influences the brain, and so stimuli are passively received and coded solely for their physical properties. In awake subjects, on the other hand, responses to stimuli are heavily modulated by ongoing mental processes (i.e. attention, expectation). The same stimulus, for instance, is interpreted differently depending on what the animal expects: humans - and their brains - led to expect a mild taste, for instance, can be "fooled" into thinking that a bitter taste is milder than it actually is. The present proposal is designed to study the neural underpinnings of such phenomena: in particular, the experiments outlined here will address the extent to which expectation influences background activity of the brain and responses to sensory stimuli. The intrinsic rewarding/aversive nature of gustatory stimuli and the importance of food selection for animal survival make taste an ideal sensory system for directly studying the effects of expectation at both the neural and behavioral level. The experiments proposed will be conducted in awake rats; ensembles of single neurons will be recorded with multiple electrodes implanted in areas known to be involved in taste and expectation (GC, orbitofrontal cortex [OFC], amygdala [AM]). Two different aspects of expectation will be investigated: generic expectation of an unknown stimulus (a process somewhat analogous to attention) and specific expectation of a known stimulus. For the first, rats will be trained to collect a taste by pressing a lever in response to a tone. In this paradigm, the tone will not provide any information regarding the identity of the taste-it will simply trigger an attentional shift related to the expectation of an unknown stimulus. Expectation of a specific stimulus, on the other hand, will be addressed in another subset of experiments involving the use of two tones, each specifically associated with a different taste. In these experiments, the auditory cues will provide information about the specific taste anticipated. Spontaneous activity, responses to anticipatory cues, and responses to unexpected and expected tastes will be recorded to parse the effects of generic and specific expectation on taste. Finally, electrodes will be implanted also in OFC and AM - two areas known to be involved in expectation - and the relationship between these two areas and GC will be studied in the experimental conditions described above. Understanding the degree to which internal states, such as expectation, shape sensory responses is a central question in the field of sensory neuroscience. The comprehension of how the brain responds to the expectation of tastes will shed light on the complexities of food selection choices of all mammals - including humans - and will provide important information which could potentially be applied to the study of obesity and eating disorders. This proposal is designed to understand the neural underpinnings of expectation of taste stimuli. Expectation plays an important role in the perception of food and in its evaluation (Deliza and MacFie 1996; Hurling and Shepherd 2003); as such, this subject has important implications on issues relevant to public health, such as food liking and selection choices. Additionally, understanding the neural basis of expectation is relevant for the study of the neural mechanisms of placebo (Nitschke et al. 2006a; Nitschke et al. 2006b; Sarinopoulos et al. 2006) - a growing field of interest in neuroscience (Petrovic et al. 2005; Ploghaus et al. 1999).

描述（由申请人提供）：大脑处理感官刺激的不同，具体取决于动物是醒着还是麻醉。在麻醉动物中，没有内部认知活性会影响大脑，因此仅针对其物理特性，被动接受和编码刺激。另一方面，在清醒对象中，对刺激的反应受到持续的心理过程（即注意，期望）的严重调节。例如，根据动物的期望，对同样的刺激进行了不同的解释：人类及其大脑 - 使人们期望一种温和的味道，可以“愚弄”以为苦味比实际情况更温和。本提案旨在研究这种现象的神经基础：特别是，此处概述的实验将解决预期影响大脑背景活动的程度以及对感觉刺激的反应。味觉刺激的内在奖励/厌恶性和食物选择对动物生存的重要性使口味成为直接研究神经和行为水平上期望的影响的理想感觉系统。提出的实验将在清醒大鼠中进行；单个神经元的集合将记录在已知参与味觉和期望的区域中的多个电极（GC，Orbitrontal Cortex [OFC]，Amygdala [am]）。将研究期望的两个不同方面：对未知刺激的通用期望（这与注意力相似）和对已知刺激的特定期望。首先，将训练大鼠通过按下杠杆来响应音调来收集品味。在此范式中，音调将无法提供有关味觉身份的任何信息，它将仅引发与未知刺激的期望有关的注意力转移。另一方面，对特定刺激的期望将在涉及使用两种音调的另一个子集中解决，每种音调都与不同的味道特别相关。在这些实验中，听觉提示将提供有关预期的特定口味的信息。将记录自发活动，对预期线索的反应以及对意外和预期口味的反应，以解析通用和特定期望对口味的影响。最后，电极也将植入OFC和AM-已知参与预期的两个区域 - 这两个区域与GC之间的关系将在上述实验条件下进行研究。了解内部状态（例如期望）形成感觉反应的程度是感觉神经科学领域的核心问题。对大脑对口味期望的反应的理解将阐明所有哺乳动物（包括人类）的食物选择选择的复杂性，并将提供重要的信息，这些信息可能有可能应用于肥胖和饮食失调的研究。该建议旨在了解味觉刺激期望的神经基础。期望在食物的感知及其评估中起着重要作用（Deliza and Macfie 1996； Hurling and Shepherd 2003）；因此，该主题对与公共卫生相关的问题（例如食物喜欢和选择选择）具有重要意义。此外，了解期望的神经基础与安慰剂神经机制的研究有关（Nitschke等，2006a; Nitschke etal。2006b; Sarinopoulos etal。2006） - 对神经科学的兴趣越来越多（Petrovic等人，Petrovic等人，2005; Ploghaus etal。1999）。