Layer 6b Is Driven by Intracortical Long-Range Projection Neurons
Summary: Layer 6b (L6b), the deepest neocortical layer, projects to cortical targets and higher-order thalamus and is the only layer responsive to the wake-promoting neuropeptide orexin/hypocretin. These characteristics suggest that L6b can strongly modulate brain state, but projections to L6b and t...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2020-03-01
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| Series: | Cell Reports |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2211124720302059 |
| _version_ | 1818309838859403264 |
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| author | Timothy A. Zolnik Julia Ledderose Maria Toumazou Thorsten Trimbuch Tess Oram Christian Rosenmund Britta J. Eickholt Robert N.S. Sachdev Matthew E. Larkum |
| author_facet | Timothy A. Zolnik Julia Ledderose Maria Toumazou Thorsten Trimbuch Tess Oram Christian Rosenmund Britta J. Eickholt Robert N.S. Sachdev Matthew E. Larkum |
| author_sort | Timothy A. Zolnik |
| collection | DOAJ |
| description | Summary: Layer 6b (L6b), the deepest neocortical layer, projects to cortical targets and higher-order thalamus and is the only layer responsive to the wake-promoting neuropeptide orexin/hypocretin. These characteristics suggest that L6b can strongly modulate brain state, but projections to L6b and their influence remain unknown. Here, we examine the inputs to L6b ex vivo in the mouse primary somatosensory cortex with rabies-based retrograde tracing and channelrhodopsin-assisted circuit mapping in brain slices. We find that L6b receives its strongest excitatory input from intracortical long-range projection neurons, including those in the contralateral hemisphere. In contrast, local intracortical input and thalamocortical input were significantly weaker. Moreover, our data suggest that L6b receives far less thalamocortical input than other cortical layers. L6b was most strongly inhibited by PV and SST interneurons. This study shows that L6b integrates long-range intracortical information and is not part of the traditional thalamocortical loop. : Zolnik et al. find that layer 6b, the deepest and least-studied neocortical layer, is an input node for cortical long-range intercommunication. Mapping the input connections of L6b reveals that this layer receives significantly stronger input from long-range intracortical neurons compared with other types of neurons, such as thalamic neurons. Keywords: layer 6, layer 6b, cortex, thalamus, long-range |
| first_indexed | 2024-12-13T07:36:32Z |
| format | Article |
| id | doaj.art-77380060326f496f988f9474bf745aec |
| institution | Directory Open Access Journal |
| issn | 2211-1247 |
| language | English |
| last_indexed | 2024-12-13T07:36:32Z |
| publishDate | 2020-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Cell Reports |
| spelling | doaj.art-77380060326f496f988f9474bf745aec2022-12-21T23:55:05ZengElsevierCell Reports2211-12472020-03-01301034923505.e5Layer 6b Is Driven by Intracortical Long-Range Projection NeuronsTimothy A. Zolnik0Julia Ledderose1Maria Toumazou2Thorsten Trimbuch3Tess Oram4Christian Rosenmund5Britta J. Eickholt6Robert N.S. Sachdev7Matthew E. Larkum8Institute for Biology, Humboldt-Universität zu Berlin, Berlin, GermanyInstitute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, GermanyInstitute for Biology, Humboldt-Universität zu Berlin, Berlin, GermanyNeuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, GermanyJanelia Research Campus, Ashburn, VA, USANeuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, GermanyNeuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, GermanyInstitute for Biology, Humboldt-Universität zu Berlin, Berlin, GermanyInstitute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany; Corresponding authorSummary: Layer 6b (L6b), the deepest neocortical layer, projects to cortical targets and higher-order thalamus and is the only layer responsive to the wake-promoting neuropeptide orexin/hypocretin. These characteristics suggest that L6b can strongly modulate brain state, but projections to L6b and their influence remain unknown. Here, we examine the inputs to L6b ex vivo in the mouse primary somatosensory cortex with rabies-based retrograde tracing and channelrhodopsin-assisted circuit mapping in brain slices. We find that L6b receives its strongest excitatory input from intracortical long-range projection neurons, including those in the contralateral hemisphere. In contrast, local intracortical input and thalamocortical input were significantly weaker. Moreover, our data suggest that L6b receives far less thalamocortical input than other cortical layers. L6b was most strongly inhibited by PV and SST interneurons. This study shows that L6b integrates long-range intracortical information and is not part of the traditional thalamocortical loop. : Zolnik et al. find that layer 6b, the deepest and least-studied neocortical layer, is an input node for cortical long-range intercommunication. Mapping the input connections of L6b reveals that this layer receives significantly stronger input from long-range intracortical neurons compared with other types of neurons, such as thalamic neurons. Keywords: layer 6, layer 6b, cortex, thalamus, long-rangehttp://www.sciencedirect.com/science/article/pii/S2211124720302059 |
| spellingShingle | Timothy A. Zolnik Julia Ledderose Maria Toumazou Thorsten Trimbuch Tess Oram Christian Rosenmund Britta J. Eickholt Robert N.S. Sachdev Matthew E. Larkum Layer 6b Is Driven by Intracortical Long-Range Projection Neurons Cell Reports |
| title | Layer 6b Is Driven by Intracortical Long-Range Projection Neurons |
| title_full | Layer 6b Is Driven by Intracortical Long-Range Projection Neurons |
| title_fullStr | Layer 6b Is Driven by Intracortical Long-Range Projection Neurons |
| title_full_unstemmed | Layer 6b Is Driven by Intracortical Long-Range Projection Neurons |
| title_short | Layer 6b Is Driven by Intracortical Long-Range Projection Neurons |
| title_sort | layer 6b is driven by intracortical long range projection neurons |
| url | http://www.sciencedirect.com/science/article/pii/S2211124720302059 |
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