Department of Neuroscience, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110.
Department of Neuroscience, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110
J Neurosci. 2021 Jun 2;41(22):4809-4825. doi: 10.1523/JNEUROSCI.2185-20.2021. Epub 2021 Apr 13.
The postrhinal area (POR) is a known center for integrating spatial with nonspatial visual information and a possible hub for influencing landmark navigation by affective input from the amygdala. This may involve specific circuits within muscarinic acetylcholine receptor 2 (M2)-positive (M2) or M2 modules of POR that associate inputs from the thalamus, cortex, and amygdala, and send outputs to the entorhinal cortex. Using anterograde and retrograde labeling with conventional and viral tracers in male and female mice, we found that all higher visual areas of the ventral cortical stream project to the amygdala, while such inputs are absent from primary visual cortex and dorsal stream areas. Unexpectedly for the presumed salt-and-pepper organization of mouse extrastriate cortex, tracing results show that inputs from the dorsal lateral geniculate nucleus and lateral posterior nucleus were spatially clustered in layer 1 (L1) and overlapped with M2 patches of POR. In contrast, input from the amygdala to L1 of POR terminated in M2 interpatches. Importantly, the amygdalocortical input to M2 interpatches in L1 overlapped preferentially with spatially clustered apical dendrites of POR neurons projecting to amygdala and entorhinal area lateral, medial (ENTm). The results suggest that subnetworks in POR, used to build spatial maps for navigation, do not receive direct thalamocortical M2 patch-targeting inputs. Instead, they involve local networks of M2 interpatches, which are influenced by affective information from the amygdala and project to ENTm, whose cells respond to visual landmark cues for navigation. A central purpose of visual object recognition is identifying the salience of objects and approaching or avoiding them. However, it is not currently known how the visual cortex integrates the multiple streams of information, including affective and navigational cues, which are required to accomplish this task. We find that in a higher visual area, the postrhinal cortex, the cortical sheet is divided into interdigitating modules receiving distinct inputs from visual and emotion-related sources. One of these modules is preferentially connected with the amygdala and provides outputs to entorhinal cortex, constituting a processing stream that may assign emotional salience to objects and landmarks for the guidance of goal-directed navigation.
后眶额皮质区（POR）是一个已知的将空间与非空间视觉信息整合的中心，并且可能是通过来自杏仁核的情感输入影响地标导航的枢纽。这可能涉及 POR 中 M2 阳性（M2）或 M2 模块内的特定回路，这些回路将来自丘脑、皮层和杏仁核的输入联系起来，并将输出发送到内嗅皮层。使用传统和病毒示踪剂在雄性和雌性小鼠中进行顺行和逆行标记，我们发现腹侧皮质流的所有高级视觉区域都投射到杏仁核，而初级视觉皮层和背侧流区域则没有这种输入。出乎意料的是，对于假定的老鼠外纹状皮层的盐和胡椒组织，追踪结果表明，来自外侧膝状体核和外侧后核的输入在层 1（L1）中空间聚类，并与 POR 的 M2 斑块重叠。相比之下，来自杏仁核的 POR L1 的输入终止于 M2 间隙。重要的是，杏仁核到 L1 中 M2 间隙的输入与投射到杏仁核和内嗅区外侧、内侧（ENTm）的 POR 神经元的空间聚类的顶端树突优先重叠。结果表明，用于构建导航空间地图的 POR 中的子网不接收直接来自丘脑皮质的 M2 斑块靶向输入。相反，它们涉及 M2 间隙的局部网络，这些网络受到来自杏仁核的情感信息的影响，并投射到 ENTm，其细胞对用于导航的视觉地标线索做出反应。视觉物体识别的主要目的是识别物体的显著性，并接近或避开它们。然而，目前尚不清楚视觉皮层如何整合包括情感和导航线索在内的多种信息流，以完成这一任务。我们发现，在一个更高的视觉区域，即后眶额皮质区，皮质片被分为从视觉和情绪相关来源接收不同输入的交错模块。其中一个模块与杏仁核优先连接，并向内嗅皮层提供输出，构成一个处理流，可能为目标导向的导航赋予物体和地标以情感显著性。
