小柯机器人

美国麻省理工学院Elly Nedivi研究组将丘脑神经支配映射到单个L2/3锥体神经元并建模出其“读出”视觉输入。相关论文于2023年2月2日在线发表于国际学术期刊《自然—神经科学》。

研究人员采用了新的方法，结合遗传工具和可伸缩的组织扩展显微镜进行全细胞突触映射，揭示了主视觉皮层的单个2/3层（L2/3）锥体细胞（PC）上的丘脑和皮质兴奋性突触的数量、密度和大小。研人员发现丘脑的输入不仅稀疏，而且在单个树突和神经元之间的数量和密度上也存在显著的异质性。最令人惊讶的是，尽管L2/3 PC上的丘脑突触稀少，但它们比皮层上的突触要小。将这些发现纳入精细尺度、解剖学上可靠的L2/3 PC生物物理模型，研究人员揭示了整合在小的异质神经元集合中的具有稀疏和微弱丘脑皮层突触的单个神经元如何可靠地“读出”视觉驱动的丘脑输入。

据悉，丘脑是感觉信息从外周到哺乳动物大脑皮层的主要通道。一个主要的难题是丘脑作为进入新皮层的主要前馈投射系统的核心作用与丘脑皮层突触的稀疏之间的差异。

附：英文原文

Title: Mapping thalamic innervation to individual L2/3 pyramidal neurons and modeling their ‘readout’ of visual input

Author: Balcioglu, Aygul, Gillani, Rebecca, Doron, Michael, Burnell, Kendyll, Ku, Taeyun, Erisir, Alev, Chung, Kwanghun, Segev, Idan, Nedivi, Elly

Issue&Volume: 2023-02-02

Abstract: The thalamus is the main gateway for sensory information from the periphery to the mammalian cerebral cortex. A major conundrum has been the discrepancy between the thalamus’s central role as the primary feedforward projection system into the neocortex and the sparseness of thalamocortical synapses. Here we use new methods, combining genetic tools and scalable tissue expansion microscopy for whole-cell synaptic mapping, revealing the number, density and size of thalamic versus cortical excitatory synapses onto individual layer 2/3 (L2/3) pyramidal cells (PCs) of the mouse primary visual cortex. We find that thalamic inputs are not only sparse, but remarkably heterogeneous in number and density across individual dendrites and neurons. Most surprising, despite their sparseness, thalamic synapses onto L2/3 PCs are smaller than their cortical counterparts. Incorporating these findings into fine-scale, anatomically faithful biophysical models of L2/3 PCs reveals how individual neurons with sparse and weak thalamocortical synapses, embedded in small heterogeneous neuronal ensembles, may reliably ‘read out’ visually driven thalamic input.

DOI: 10.1038/s41593-022-01253-9

Source: https://www.nature.com/articles/s41593-022-01253-9

Nature Neuroscience：《自然—神经科学》，创刊于1998年。隶属于施普林格·自然出版集团，最新IF：28.771
官方网址：https://www.nature.com/neuro/
投稿链接：https://mts-nn.nature.com/cgi-bin/main.plex