Taste responses in defined cell types in gustatory cortex

 描述(由申请人提供)：胃肠道决定在许多人类疾病中起着关键作用，包括肥胖、糖尿病、厌食症、高血压和冠状动脉疾病。控制这些决定的最重要因素之一是味觉。哺乳动物的味觉皮质参与味觉学习和行为，电生理学研究表明，该区域的味觉激活神经元往往是宽调的(关于味觉质量)、多模式和受行为状态调节。然而，目前尚不清楚味觉质量本身是如何在GC中编码的，也不清楚单个神经元中的刺激调谐是否会随着细胞类型或功能连接的不同而变化。双光子(2P)成像是一种允许同时记录体内大量神经元的味觉诱发反应的技术。然而，到目前为止，关于味觉系统的2P研究只发表了几篇。我们将结合2P成像和特定的细胞类型鉴定，通过Cre依赖的表达或逆行标记来完成。总而言之，这些实验将检验这一假设，即GC神经元的味觉敏感度和调谐曲线作为皮质深度、细胞类型(锥体细胞与中间神经元)或投射模式的函数而变化。目的1将研究表达Thy1的锥体细胞和表达Calretinin的中间神经元的味觉反应与GC中更大数量的标记细胞的比较。目的2研究味觉丘脑或杏仁基底外侧核逆行标记的GC神经元的味觉反应。

 DESCRIPTION (provided by applicant): Ingestive decisions play a key role in a number of human conditions including obesity, diabetes, anorexia, hypertension, and coronary artery disease. One of the most important factors regulating these decisions is the sense of taste. The gustatory cortex in mammals has been shown to be involved in taste learning and behavior, and electrophysiological studies have shown that taste-activated neurons in this area tend to be broadly tuned (with regard to taste quality), multi-modal, and modulated by behavioral state. However, it is not clear how taste quality itself is encoded in the GC, and whether stimulus tuning in individual neurons varies as a function of cell type or functional connection. Two-photon (2P) imaging is a technique that allows for the simultaneous recording of taste-evoked responses in a large numbers of neurons in vivo. However, only a couple of 2P studies in the taste system have been published to date. We will combine 2P imaging with specific identification of cell types, accomplished by either Cre-dependent expression or retrograde labeling. Collectively, these experiments will test the hypothesis that taste sensitivities and tuning profile vary in GC neurons as a function of cortical depth, cell type (pyramidal cell vs. interneuron) or projection pattern. Aim 1 will investigate compare taste responses in Thy1-expressing pyramidal cells and Calretinin-expressing interneurons to the greater population of all labeled cells in GC. Aim 2 will investigate taste responses in GC neurons retrogradely labeled from either gustatory thalamus or basolateral amygdala.