小柯机器人

德国慕尼黑大学Laura Busse及其研究团队的研究发现皮质丘脑间反馈重塑小鼠丘脑视觉空间整合。2021年11月11日出版的《自然-神经科学》杂志发表了这项成果。

研究人员发现清醒小鼠，其视网膜组织的皮质反馈会增强感受野(RF)并增加背外侧膝状核(dLGN）周围的抑制。网络模型认为，广泛抑制性皮质丘脑(CT)反馈是重现这些效果所必需的，研究人员针对丘脑网状核(visTRN)的视觉扇区进行记录。

研究发现visTRN神经元具有较大的RF，具有很弱的周围抑制并对大刺激表现出强烈的反馈依赖反应。这些功能使它们成为dLGN中调节反馈增强环绕声抑制的理想选择。该研究认为皮层反馈塑造了dLGN中的空间整合，可能通过visTRN招募神经元。

研究人员表示，视觉信息通过丘脑dLGN从视网膜传递至皮层，其中广泛CT反馈参与调控空间处理。仍然未知这种调节如何从直接兴奋性和间接抑制性CT反馈途径中产生。

附：英文原文

Title: Corticothalamic feedback sculpts visual spatial integration in mouse thalamus

Author: Born, Gregory, Schneider-Soupiadis, Felix A., Erisken, Sinem, Vaiceliunaite, Agne, Lao, Chu Lan, Mobarhan, Milad H., Spacek, Martin A., Einevoll, Gaute T., Busse, Laura

Issue&Volume: 2021-11-11

Abstract: En route from the retina to the cortex, visual information passes through the dorsolateral geniculate nucleus (dLGN) of the thalamus, where extensive corticothalamic (CT) feedback has been suggested to modulate spatial processing. How this modulation arises from direct excitatory and indirect inhibitory CT feedback pathways remains enigmatic. Here, we show that in awake mice, retinotopically organized cortical feedback sharpens receptive fields (RFs) and increases surround suppression in the dLGN. Guided by a network model indicating that widespread inhibitory CT feedback is necessary to reproduce these effects, we targeted the visual sector of the thalamic reticular nucleus (visTRN) for recordings. We found that visTRN neurons have large RFs, show little surround suppression and exhibit strong feedback-dependent responses to large stimuli. These features make them an ideal candidate for mediating feedback-enhanced surround suppression in the dLGN. We conclude that cortical feedback sculpts spatial integration in the dLGN, likely via recruitment of neurons in the visTRN. The authors show that retinotopically organized feedback from the primary visual cortex sharpens receptive fields and contributes to surround suppression in mouse visual thalamus, probably by recruiting inhibition through the thalamic reticular nucleus.

DOI: 10.1038/s41593-021-00943-0

Source: https://www.nature.com/articles/s41593-021-00943-0

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