Role of Glutamate and CCK in PBN Taste Reactivity

谷氨酸和 CCK 在 PBN 味觉反应中的作用

• 批准号: 7008313
• 负责人: Michael Stephen King
• 金额: $ 3.4万
• 依托单位: STETSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7008313
• 关键词: behavior test; behavioral /social science research tag; cholecystokinin; glutamate receptor; laboratory rat; neural information processing; neurons; nutrient intake activity; nutrition related tag; parabrachial nucleus; psychomotor function; psychomotor reaction time; psychophysiology; stimulus /response; taste; videotape /videodisc

DESCRIPTION (provided by applicant): The long-term goal of this research is to elucidate the central neural mechanisms underlying feeding-related behaviors initiated by taste input in the rat. Recent studies have focused on the neurochemistry of two brainstem areas that receive gustatory sensory information, the rostral nucleus of the solitary tract and the parabrachial nucleus (PBN). The role of the PBN in the processing of sensory information and the initiation of oromotor responses is particularly intriguing since neurons in the PBN process taste-related sensory information and project to the network of motor neurons in the medulla that controls oromotor behaviors. Suggesting a role for glutamatergic neurotransmission within the PBN in the initiation of oromotor behaviors, microinjection of glutamate directly into the taste regions of the PBN in conscious rats elicits ingestive behaviors like mouth movements and tongue protrusions. Therefore, the first specific aim of the proposed study is to determine the role of glutamate receptors within the PBN in oromotor behaviors elicited by taste stimulation. It is hypothesized that the activitation of glutamate receptors is necessary for normal behavioral responses. Cholecystokinin (CCK) is a gut peptide that has satiety effects. There is some evidence that CCK modulates ingestive behaviors but a specific functional role for CCK and its receptors within the PBN has not been addressed. Therefore, the second specific aim of the proposed study is to determine the role of CCK in the PBN in oromotor behaviors elicited by intra-oral infusion of taste solutions in conscious rats. The hypothesis is that, consistent with its role in satiety, CCK will reduce ingestive oromotor responses to taste input. Both specific aims will be addressed by implanting cannula into the PBN as well as into the oral cavity so that glutamate or CCK receptor blockers can be injected into the PBN immediately prior to infusing taste solutions into the oral cavity in conscious rats. The proposed research is relevant to public health because it will improve the understanding of the neural circuits within the brainstem that control behavioral responses to taste input. These behavioral responses are critical to survival since they result in the acceptance of appropriate foods and rejection of potential toxins. Specifically, data collected during the proposed investigation will determine if glutamate and CCK in the PBN play a critical role in the assessment of ingested substances and subsequent behavioral responses.

描述（由申请人提供）：本研究的长期目标是阐明大鼠味觉输入引发的进食相关行为的中枢神经机制。最近的研究集中在接收味觉感觉信息的两个脑干区域的神经化学，即孤束的喙核和臂旁核（PBN）。 PBN 在感觉信息处理和口运动反应启动中的作用特别有趣，因为 PBN 中的神经元处理与味觉相关的感觉信息，并投射到髓质中控制口运动行为的运动神经元网络。表明 PBN 内的谷氨酸能神经传递在口部运动行为启动中的作用，将谷氨酸直接显微注射到有意识的大鼠 PBN 的味觉区域会引发嘴部运动和舌头伸出等摄取行为。因此，本研究的第一个具体目标是确定 PBN 内谷氨酸受体在味觉刺激引起的口腔运动行为中的作用。据推测，谷氨酸受体的激活对于正常的行为反应是必要的。胆囊收缩素 (CCK) 是一种具有饱腹感作用的肠道肽。有一些证据表明 CCK 调节摄取行为，但 CCK 及其 PBN 内受体的特定功能作用尚未得到解决。因此，本研究的第二个具体目标是确定 PBN 中的 CCK 在清醒大鼠口内输注味觉溶液引起的口腔运动行为中的作用。假设认为，与其在饱腹感中的作用一致，CCK 会减少对味觉输入的摄食口运动反应。这两个具体目标将通过将插管植入 PBN 以及口腔中来实现，以便在将味觉溶液注入清醒大鼠的口腔之前，将谷氨酸或 CCK 受体阻滞剂注射到 PBN 中。拟议的研究与公共卫生相关，因为它将提高对脑干内控制对味觉输入的行为反应的神经回路的理解。这些行为反应对于生存至关重要，因为它们会导致接受适当的食物并拒绝潜在的毒素。具体来说，在拟议的调查期间收集的数据将确定 PBN 中的谷氨酸和 CCK 是否在评估摄入物质和随后的行为反应中发挥关键作用。