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

项目摘要/摘要 动物需要学习和记住营养和有毒食物来源的位置，以求生存和 适应外部环境的变化。因此，有必要将位置与奖励联系起来 以及空间环境中令人厌恶的味觉体验--这些本质上是插曲体验，形成 味觉和空间位置的联想记忆。众所周知，海马体对于癫痫发作是必要的。 记忆和空间认知地图的形成，味觉皮质(GC)在味觉中起着中心作用 知觉以及适口性和价码。但这两个区域的神经元网络是如何 交互以将味觉适口性信息与它们发生的空间背景相关联，以及如何实现 相互作用推动了随后的行为探索，以接近潜在的食物来源，这在很大程度上是未知的。我们 最近在老鼠身上发现了海马区CA1区细胞的一个子集，它基于 适口性，为解决这些问题提供了基础。我们发现有味觉反应的CA1细胞 在一个较慢的时间尺度上编码味觉适口性以响应味觉刺激，并且这些味觉反应被选通 由单个细胞的空间反应决定。此外，我们还证明了这种味觉反应的空间编码 在尖锐波纹(SWR)期间，通过离线重新激活来细化CA1子网络。在这里，我们将使用 多部位电生理学、行为分析和区域间光遗传操作相结合 连接性研究海马-味觉皮质相互作用在空间认知形成中的作用 生态相关食物刺激物的地图。特别是，我们假设CA1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 在大鼠学习将食欲与食欲联系起来时，使用GC和CA1区神经丛的同步记录 以及在可适应的迷宫中特定位置的厌恶口味，量化探索路径如何随 品尝体验。我们将研究味觉位置编码在CA1中的发展以及与味觉位置编码的协调 GC和CA1活性在食物来源的适口性编码服务中的作用。接下来，我们将测试SWR是否在 在CA1和GC中，食物来源的海马体与味觉特定的重新激活同时相关，并且 是否存在味觉重新激活与能够支持味觉定位的位置信息的协调 联想。最后，我们将使用从味觉系统到海马体的输入的光遗传扰动 以测试这是否会扰乱对空间位置的辨别性记忆的形成 偏爱的口味。总而言之，这些目标将为海马体中的网络如何相互作用提供关键的洞察力 通过调节味觉的初级感觉皮质网络，以便嵌入与行为学相关的 空间认知地图中的食物信息，从而使动物能够成功地在味觉空间导航 认知图。

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.