Topographically organized representation of space and context in the medial prefrontal cortex
Topographically organized representation of space and context in the medial prefrontal cortex
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DOI：
10.1101/2021.06.04.447085
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发表时间：
2021-06
影响因子：
11.1
通讯作者：
Jonas-Frederic Sauer;Shani Folschweiller;M. Bartos
中科院分区：
文献类型：
--
作者：
Jonas-Frederic Sauer;Shani Folschweiller;M. Bartos
意义新皮质由具有特殊功能的区域组成(例如，感觉和联想)。尽管功能多样，但新出现的证据表明，对空间进行编码可能是大脑皮层回路的普遍特征。在这里，我们确定了沿腹背轴的空间调谐深度的梯度。空间调谐特性的复杂地形图可能支持内侧前额叶皮质子网络之间的分工，以支持与执行上下文相关行为结果相关的局部电路计算。新皮质锥体细胞的空间调谐在不同的皮质区域被观察到，并被认为主要依赖于来自海马结构的输入。尽管对海马区的位置编码进行了很好的研究，但对新皮质空间调谐系统的许多特性仍然不够了解。特别是，从海马到新皮质的直接解剖连接的地形如何影响空间调节深度，以及海马输出区CA1的空间编码动态，如在新环境中的重新映射，是否传递到新皮质，目前尚不清楚。通过使用老鼠在虚拟环境中导航，我们在小鼠的内侧前额叶皮质解决了这些问题，该皮质接受来自海马体的直接输入。我们发现，在没有任务规则的情况下，空间的前额叶表征迅速出现，它区分熟悉的环境和新的环境，并在重新暴露于相同的熟悉环境时恢复。地形图分析显示，在表示自己的位置时存在背腹倾斜，这与海马区输入的神经密度相反。这些结果共同揭示了自发运动过程中动态出现的、按地形组织的前额叶位置编码。
Significance The neocortex is composed of areas with specialized functions (e.g., sensory versus associational). Despite this functional diversity, emerging evidence suggests that the encoding of space might be a universal feature of cortical circuits. Here, we identified a gradient of spatial tuning depth along the dorsoventral axis. A complex topography of spatial tuning properties might support a division of labor among medial prefrontal cortical subnetworks to support local circuit computation relevant for the execution of context-dependent behavioral outcomes. Spatial tuning of neocortical pyramidal cells has been observed in diverse cortical regions and is thought to rely primarily on input from the hippocampal formation. Despite the well-studied hippocampal place code, many properties of the neocortical spatial tuning system are still insufficiently understood. In particular, it has remained unclear how the topography of direct anatomical connections from hippocampus to neocortex affects spatial tuning depth, and whether the dynamics of spatial coding in the hippocampal output region CA1, such as remapping in novel environments, is transmitted to the neocortex. Using mice navigating through virtual environments, we addressed these questions in the mouse medial prefrontal cortex, which receives direct input from the hippocampus. We found a rapidly emerging prefrontal representation of space in the absence of task rules, which discriminates familiar from novel environments and is reinstated upon reexposure to the same familiar environment. Topographical analysis revealed a dorsoventral gradient in the representation of the own position, which runs opposite to the innervation density of hippocampal inputs. Jointly, these results reveal a dynamically emerging and topographically organized prefrontal place code during spontaneous locomotion.