Cargando…
Layer 5 of cortex innervates the thalamic reticular nucleus in mice
Neurons in the thalamic reticular nucleus (TRN) are a primary source of inhibition to the dorsal thalamus and, as they are innervated in part by the cortex, are a means of corticothalamic regulation. Previously, cortical inputs to the TRN were thought to originate solely from layer 6 (L6), but we re...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
National Academy of Sciences
2022
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9499584/ https://www.ncbi.nlm.nih.gov/pubmed/36095204 http://dx.doi.org/10.1073/pnas.2205209119 |
_version_ | 1784795027055050752 |
---|---|
author | Carroll, Briana J. Sampathkumar, Vandana Kasthuri, Narayanan Sherman, S. Murray |
author_facet | Carroll, Briana J. Sampathkumar, Vandana Kasthuri, Narayanan Sherman, S. Murray |
author_sort | Carroll, Briana J. |
collection | PubMed |
description | Neurons in the thalamic reticular nucleus (TRN) are a primary source of inhibition to the dorsal thalamus and, as they are innervated in part by the cortex, are a means of corticothalamic regulation. Previously, cortical inputs to the TRN were thought to originate solely from layer 6 (L6), but we recently reported the presence of putative synaptic terminals from layer 5 (L5) neurons in multiple cortical areas in the TRN [J. A. Prasad, B. J. Carroll, S. M. Sherman, J. Neurosci. 40, 5785–5796 (2020)]. Here, we demonstrate with electron microscopy that L5 terminals from multiple cortical regions make bona fide synapses in the TRN. We further use light microscopy to localize these synapses relative to recently described TRN subdivisions and show that L5 terminals target the edges of the somatosensory TRN, where neurons reciprocally connect to higher-order thalamus, and that L5 terminals are scarce in the core of the TRN, where neurons reciprocally connect to first-order thalamus. In contrast, L6 terminals densely innervate both edge and core subregions and are smaller than those from L5. These data suggest that a sparse but potent input from L5 neurons of multiple cortical regions to the TRN may yield transreticular inhibition targeted to higher-order thalamus. |
format | Online Article Text |
id | pubmed-9499584 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | National Academy of Sciences |
record_format | MEDLINE/PubMed |
spelling | pubmed-94995842023-03-12 Layer 5 of cortex innervates the thalamic reticular nucleus in mice Carroll, Briana J. Sampathkumar, Vandana Kasthuri, Narayanan Sherman, S. Murray Proc Natl Acad Sci U S A Biological Sciences Neurons in the thalamic reticular nucleus (TRN) are a primary source of inhibition to the dorsal thalamus and, as they are innervated in part by the cortex, are a means of corticothalamic regulation. Previously, cortical inputs to the TRN were thought to originate solely from layer 6 (L6), but we recently reported the presence of putative synaptic terminals from layer 5 (L5) neurons in multiple cortical areas in the TRN [J. A. Prasad, B. J. Carroll, S. M. Sherman, J. Neurosci. 40, 5785–5796 (2020)]. Here, we demonstrate with electron microscopy that L5 terminals from multiple cortical regions make bona fide synapses in the TRN. We further use light microscopy to localize these synapses relative to recently described TRN subdivisions and show that L5 terminals target the edges of the somatosensory TRN, where neurons reciprocally connect to higher-order thalamus, and that L5 terminals are scarce in the core of the TRN, where neurons reciprocally connect to first-order thalamus. In contrast, L6 terminals densely innervate both edge and core subregions and are smaller than those from L5. These data suggest that a sparse but potent input from L5 neurons of multiple cortical regions to the TRN may yield transreticular inhibition targeted to higher-order thalamus. National Academy of Sciences 2022-09-12 2022-09-20 /pmc/articles/PMC9499584/ /pubmed/36095204 http://dx.doi.org/10.1073/pnas.2205209119 Text en Copyright © 2022 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by-nc-nd/4.0/This article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND) (https://creativecommons.org/licenses/by-nc-nd/4.0/) . |
spellingShingle | Biological Sciences Carroll, Briana J. Sampathkumar, Vandana Kasthuri, Narayanan Sherman, S. Murray Layer 5 of cortex innervates the thalamic reticular nucleus in mice |
title | Layer 5 of cortex innervates the thalamic reticular nucleus in mice |
title_full | Layer 5 of cortex innervates the thalamic reticular nucleus in mice |
title_fullStr | Layer 5 of cortex innervates the thalamic reticular nucleus in mice |
title_full_unstemmed | Layer 5 of cortex innervates the thalamic reticular nucleus in mice |
title_short | Layer 5 of cortex innervates the thalamic reticular nucleus in mice |
title_sort | layer 5 of cortex innervates the thalamic reticular nucleus in mice |
topic | Biological Sciences |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9499584/ https://www.ncbi.nlm.nih.gov/pubmed/36095204 http://dx.doi.org/10.1073/pnas.2205209119 |
work_keys_str_mv | AT carrollbrianaj layer5ofcortexinnervatesthethalamicreticularnucleusinmice AT sampathkumarvandana layer5ofcortexinnervatesthethalamicreticularnucleusinmice AT kasthurinarayanan layer5ofcortexinnervatesthethalamicreticularnucleusinmice AT shermansmurray layer5ofcortexinnervatesthethalamicreticularnucleusinmice |