Neske Garrett T, Cardin Jessica A
Department of Neuroscience, Kavli Institute for Neuroscience, Wu Tsai Neuroscience Institute, Yale University, New Haven, CT, USA.
Present address: Department of Physiology and Biophysics, State University of New York at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY, USA.
bioRxiv. 2023 Oct 10:2023.10.08.561424. doi: 10.1101/2023.10.08.561424.
Communication among different neocortical areas is largely thought to be mediated by long-range synaptic interactions between cortical neurons, with the thalamus providing only an initial relay of information from the sensory periphery. Higher-order thalamic nuclei receive strong synaptic inputs from the cortex and send robust projections back to other cortical areas, providing a distinct and potentially critical route for cortico-cortical communication. However, the relative contributions of corticocortical and thalamocortical inputs to higher-order cortical function remain unclear. Using imaging of cortical neurons and projection axon terminals in combination with optogenetic manipulations, we find that the higher-order visual thalamus of mice conveys a specialized stream of information to higher-order visual cortex. Whereas corticocortical projections from lower cortical areas convey robust visual information, higher-order thalamocortical projections convey strong behavioral state information. Together, these findings suggest a key role for higher-order thalamus in providing contextual signals that flexibly modulate sensory processing in higher-order cortex.
人们普遍认为，不同新皮质区域之间的通信主要由皮质神经元之间的长距离突触相互作用介导，丘脑仅提供来自感觉外周的信息的初始中继。高阶丘脑核从皮质接收强烈的突触输入，并向其他皮质区域发送强大的投射，为皮质-皮质通信提供了一条独特且可能至关重要的途径。然而，皮质-皮质输入和丘脑-皮质输入对高阶皮质功能的相对贡献仍不清楚。通过结合光遗传学操作对皮质神经元和投射轴突终末进行成像，我们发现小鼠的高阶视觉丘脑向高阶视觉皮质传递了一股专门的信息流。虽然来自较低皮质区域的皮质-皮质投射传递了强大的视觉信息，但高阶丘脑-皮质投射传递了强烈的行为状态信息。这些发现共同表明，高阶丘脑在提供灵活调节高阶皮质中感觉处理的背景信号方面起着关键作用。
