Effects of expectation on gustatory cortex activity

期望对味觉皮层活动的影响

• 批准号: 7694006
• 负责人: Alfredo Fontanini
• 金额: $ 3.27万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 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/7694006
• 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）：根据动物是清醒还是麻醉，大脑对感觉刺激的处理方式有所不同。在麻醉动物中，内部认知活动不会影响大脑，因此刺激是被动接收的，并且仅根据其物理特性进行编码。另一方面，在清醒的受试者中，对刺激的反应很大程度上受到持续的心理过程（即注意力、期望）的调节。例如，根据动物的期望，相同的刺激会有不同的解释：例如，人类和他们的大脑导致预期温和的味道，可能会被“愚弄”，认为苦味比实际味道更温和。本提案旨在研究此类现象的神经基础：特别是，此处概述的实验将解决预期影响大脑背景活动和对感官刺激的反应的程度。味觉刺激的内在奖励/厌恶性质以及食物选择对动物生存的重要性使得味觉成为直接研究神经和行为水平上的期望影响的理想感觉系统。拟议的实验将在清醒的老鼠身上进行；将通过植入已知与味觉和期望有关的区域（GC、眶额皮层 [OFC]、杏仁核 [AM]）的多个电极来记录单个神经元的集合。将研究期望的两个不同方面：未知刺激的一般期望（有点类似于注意力的过程）和已知刺激的特定期望。首先，将训练老鼠通过按下杠杆来响应音调来收集味道。在这种范式中，语气不会提供有关味道特性的任何信息，它只会触发与未知刺激的预期相关的注意力转移。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组实验中得到解决，每种音调都与不同的味道具体相关。在这些实验中，听觉线索将提供有关预期特定味道的信息。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将被记录下来，以解析一般和特定期望对口味的影响。最后，电极还将被植入 OFC 和 AM（已知与预期有关的两个区域），并且将在上述实验条件下研究这两个区域与 GC 之间的关系。了解内部状态（例如期望）塑造感觉反应的程度是感觉神经科学领域的核心问题。了解大脑如何对口味期望做出反应将有助于揭示包括人类在内的所有哺乳动物食物选择的复杂性，并将提供可能应用于肥胖和饮食失调研究的重要信息。该提案旨在了解味觉刺激预期的神经基础。期望在对食物的感知和评价中起着重要作用（Deliza 和 MacFie 1996；Hurling 和 Shepherd 2003）；因此，这个主题对与公共卫生相关的问题具有重要影响，例如食物喜好和选择。此外，了解期望的神经基础与安慰剂神经机制的研究相关（Nitschke et al. 2006a；Nitschke et al. 2006b；Sarinopoulos et al. 2006）——神经科学中一个日益增长的兴趣领域（Petrovic et al. 2005；普洛豪斯等人，1999。