Hippocampal - gustatory cortical interactions underlying formation of taste-space cognitive maps

项目概要/摘要 动物需要学习和记住有营养和有毒食物来源的位置，以生存， 适应外部环境的变化。因此，有必要将地点与奖励联系起来， 和厌恶性的味觉体验--这些基本上是情景体验， 对口味和空间位置的联想记忆。众所周知，海马体是必要的， 记忆和空间认知地图的形成，而味觉皮层（GC）在味觉中起着核心作用 感知以及适口性和价编码。但这两个区域的神经元网络如何 交互以将味道适口性信息与它们出现的空间背景相关联，以及这种交互如何 相互作用驱动随后的行为探索接近潜在的食物来源，在很大程度上是未知的。我们 最近在大鼠中发现了海马CA 1区细胞的一个亚群， 适口性，为解决这些问题提供了基础。我们发现味觉反应的CA 1细胞 在响应于味觉刺激的慢时间尺度上编码味觉适口性，并且这些味觉响应被门控 通过单个细胞的空间反应。此外，我们还表明这种味觉反应的空间编码 CA 1子网络通过在尖锐波波纹（SWR）期间离线重新激活来细化。在这里，我们将使用 多位点电生理学、行为分析和区域间光遗传学操纵的组合 连接，以研究大脑皮层-味觉皮层相互作用在形成空间认知中的作用 生态相关食物刺激图。特别是，我们假设CA 1和GC中的网络相互作用， 学习、形成和回忆与特定味觉体验相关的位置记忆。我们将首先 使用GC和CA 1区域的神经集合的同时记录，因为大鼠学习将食欲 和厌恶的口味与特定的位置在一个适应性强的迷宫，量化探索路径如何变化， 品味体验我们将研究CA 1中味觉定位编码的发展以及 GC和CA 1活性在食物来源地点的适口性编码服务。接下来，我们将测试 食物来源的海马体与CA 1和GC中的味觉特异性再激活同时相关， 是否存在味觉和位置信息的重新激活的协调，其可以支持味觉-位置 协会.最后，我们将使用光遗传学扰动从味觉系统到海马的输入 在食物取样过程中，测试这是否会破坏对空间位置的辨别记忆的形成， 喜欢的口味总之，这些目标将为海马体中的网络如何相互作用提供重要的见解 与介导味觉的初级感觉皮层网络，以嵌入行为学相关的 食物信息的空间认知地图，从而使动物能够成功地导航味觉空间 认知地图

Project Summary/ Abstract Animals need to learn and remember the locations of nourishing and toxic food sources for survival and for adapting to changes in the external environment. It is therefore necessary to associate locations with rewarding and aversive taste experiences in spatial contexts – these are essentially episodic experiences that form associative memories of tastes and spatial locations. It is known that the hippocampus is necessary for episodic memories and formation of spatial cognitive maps, and the gustatory cortex (GC) plays a central role in taste perception as well as for palatability and valence coding. But how networks of neurons in these two regions interact to associate taste palatability information with the spatial contexts in which they occur, and how such interactions drive subsequent behavioral exploration to approach potential food sources, is largely unknown. We have recently discovered a subset of hippocampal CA1 place cells in rats that discriminate tastes based on palatability, providing a foundation for addressing these questions. We found that taste responsive CA1 cells encode taste palatability on a slow timescale in response to taste stimuli, and these taste responses are gated by the spatial responses of individual cells. Further, we also showed that spatial coding of this taste-responsive CA1 sub-network is refined through offline reactivation during sharp-wave ripples (SWRs). Here, we will use a combination of multisite electrophysiology, analyses of behavior, and optogenetic manipulation of inter-regional connectivity to investigate the role of hippocampal-gustatory cortical interactions in forming a spatial cognitive map of ecologically relevant food stimuli. In particular, we hypothesize that networks in CA1 and GC interact for learning, formation, and recall of memories of locations associated with specific taste experiences. We will first use simultaneous recordings from neural ensembles in GC and CA1 regions as rats learn to associate appetitive and aversive tastes with specific locations in an adaptable maze, quantifying how exploration paths change with taste experience. We will investigate the development of taste-location coding in CA1 and the coordination of GC and CA1 activity in service of palatability coding at food source locations. Next, we will test if SWRs in hippocampus at food sources are associated with taste-specific reactivation simultaneously in CA1 and GC, and whether there is coordination of reactivation of taste and location information that can support taste-location associations. Finally, we will use optogenetic perturbation of the input from the taste system to the hippocampus during food sampling to test if this will disrupt formation of discriminative memories for spatial locations of preferred tastes. Together, these aims will provide crucial insight into how networks in the hippocampus interact with primary sensory cortical networks that mediate taste perception, in order to embed ethologically relevant food information in the spatial cognitive map, thus enabling animals to successfully navigate a taste-space cognitive map.