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Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits
The tachykinin peptide substance P (SP) is expressed by many interneurons and some projection neurons in the superficial dorsal horn of the spinal cord. We have recently shown that SP-expressing excitatory interneurons in lamina II correspond largely to a morphological class known as radial cells. H...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Elsevier Science
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7717171/ https://www.ncbi.nlm.nih.gov/pubmed/32634530 http://dx.doi.org/10.1016/j.neuroscience.2020.06.038 |
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author | Polgár, Erika Bell, Andrew M. Gutierrez-Mecinas, Maria Dickie, Allen C. Akar, Oğuz Costreie, Miruna Watanabe, Masahiko Todd, Andrew J. |
author_facet | Polgár, Erika Bell, Andrew M. Gutierrez-Mecinas, Maria Dickie, Allen C. Akar, Oğuz Costreie, Miruna Watanabe, Masahiko Todd, Andrew J. |
author_sort | Polgár, Erika |
collection | PubMed |
description | The tachykinin peptide substance P (SP) is expressed by many interneurons and some projection neurons in the superficial dorsal horn of the spinal cord. We have recently shown that SP-expressing excitatory interneurons in lamina II correspond largely to a morphological class known as radial cells. However, little is known about their function, or their synaptic connectivity. Here we use a modification of the Brainbow technique to define the excitatory synaptic input to SP radial cells. We show that around half of their excitatory synapses (identified by expression of Homer) are from boutons with VGLUT2, which are likely to originate mainly from local interneurons. The remaining synapses presumably include primary afferents, which generally have very low levels of VGLUT2. Our results also suggest that the SP cells are preferentially innervated by a population of excitatory interneurons defined by expression of green fluorescent protein under control of the gene for gastrin-releasing peptide, and that they receive sparser input from other types of excitatory interneuron. We show that around 40% of lamina I projection neurons express Tac1, the gene encoding substance P. Finally, we show that silencing Tac1-expressing cells in the dorsal horn results in a significant reduction in reflex responses to cold and radiant heat, but does not affect withdrawal to von Frey hairs, or chloroquine-evoked itch. |
format | Online Article Text |
id | pubmed-7717171 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Elsevier Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-77171712020-12-09 Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits Polgár, Erika Bell, Andrew M. Gutierrez-Mecinas, Maria Dickie, Allen C. Akar, Oğuz Costreie, Miruna Watanabe, Masahiko Todd, Andrew J. Neuroscience Research Article The tachykinin peptide substance P (SP) is expressed by many interneurons and some projection neurons in the superficial dorsal horn of the spinal cord. We have recently shown that SP-expressing excitatory interneurons in lamina II correspond largely to a morphological class known as radial cells. However, little is known about their function, or their synaptic connectivity. Here we use a modification of the Brainbow technique to define the excitatory synaptic input to SP radial cells. We show that around half of their excitatory synapses (identified by expression of Homer) are from boutons with VGLUT2, which are likely to originate mainly from local interneurons. The remaining synapses presumably include primary afferents, which generally have very low levels of VGLUT2. Our results also suggest that the SP cells are preferentially innervated by a population of excitatory interneurons defined by expression of green fluorescent protein under control of the gene for gastrin-releasing peptide, and that they receive sparser input from other types of excitatory interneuron. We show that around 40% of lamina I projection neurons express Tac1, the gene encoding substance P. Finally, we show that silencing Tac1-expressing cells in the dorsal horn results in a significant reduction in reflex responses to cold and radiant heat, but does not affect withdrawal to von Frey hairs, or chloroquine-evoked itch. Elsevier Science 2020-12-01 /pmc/articles/PMC7717171/ /pubmed/32634530 http://dx.doi.org/10.1016/j.neuroscience.2020.06.038 Text en © 2020 The Authors http://creativecommons.org/licenses/by/4.0/ This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Research Article Polgár, Erika Bell, Andrew M. Gutierrez-Mecinas, Maria Dickie, Allen C. Akar, Oğuz Costreie, Miruna Watanabe, Masahiko Todd, Andrew J. Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits |
title | Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits |
title_full | Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits |
title_fullStr | Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits |
title_full_unstemmed | Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits |
title_short | Substance P-expressing Neurons in the Superficial Dorsal Horn of the Mouse Spinal Cord: Insights into Their Functions and their Roles in Synaptic Circuits |
title_sort | substance p-expressing neurons in the superficial dorsal horn of the mouse spinal cord: insights into their functions and their roles in synaptic circuits |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7717171/ https://www.ncbi.nlm.nih.gov/pubmed/32634530 http://dx.doi.org/10.1016/j.neuroscience.2020.06.038 |
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