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Distinct Age-Dependent C Fiber-Driven Oscillatory Activity in the Rat Somatosensory Cortex

When skin afferents are activated, the sensory signals are transmitted to the spinal cord and eventually reach the primary somatosensory cortex (S1), initiating the encoding of the sensory percept in the brain. While subsets of primary afferents mediate specific somatosensory information from an ear...

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Autores principales: Chang, Pishan, Fabrizi, Lorenzo, Fitzgerald, Maria
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Society for Neuroscience 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7545434/
https://www.ncbi.nlm.nih.gov/pubmed/32759177
http://dx.doi.org/10.1523/ENEURO.0036-20.2020
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author Chang, Pishan
Fabrizi, Lorenzo
Fitzgerald, Maria
author_facet Chang, Pishan
Fabrizi, Lorenzo
Fitzgerald, Maria
author_sort Chang, Pishan
collection PubMed
description When skin afferents are activated, the sensory signals are transmitted to the spinal cord and eventually reach the primary somatosensory cortex (S1), initiating the encoding of the sensory percept in the brain. While subsets of primary afferents mediate specific somatosensory information from an early age, the subcortical pathways that transmit this information undergo striking changes over the first weeks of life, reflected in the gradual emergence of specific sensory behaviors. We therefore hypothesized that this period is associated with differential changes in the encoding of incoming afferent volleys in S1. To test this, we compared S1 responses to A fiber skin afferent stimulation and A + C skin afferent fiber stimulation in lightly anaesthetized male rats at postnatal day (P)7, P14, P21, and P30. Differences in S1 activity following A and A + C fiber stimulation changed dramatically over this period. At P30, A + C fiber stimulation evoked significantly larger γ, β, and α energy increases compared with A fiber stimulation alone. At younger ages, the changes in S1 oscillatory activity evoked by the two afferent volleys were not significantly different. Silencing TRPV1+ C fibers with QX-314 significantly reduced the γ and β S1 oscillatory energy increases evoked by A + C fibers, at P30 and P21, but not at younger ages. Thus, C fibers differentially modulate S1 oscillatory activity only from the third postnatal week, well after the functional maturation of the somatosensory cortex. This age-related change in afferent evoked S1 oscillatory activity may underpin the maturation of sensory discrimination in the developing brain.
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spelling pubmed-75454342020-10-09 Distinct Age-Dependent C Fiber-Driven Oscillatory Activity in the Rat Somatosensory Cortex Chang, Pishan Fabrizi, Lorenzo Fitzgerald, Maria eNeuro Research Article: New Research When skin afferents are activated, the sensory signals are transmitted to the spinal cord and eventually reach the primary somatosensory cortex (S1), initiating the encoding of the sensory percept in the brain. While subsets of primary afferents mediate specific somatosensory information from an early age, the subcortical pathways that transmit this information undergo striking changes over the first weeks of life, reflected in the gradual emergence of specific sensory behaviors. We therefore hypothesized that this period is associated with differential changes in the encoding of incoming afferent volleys in S1. To test this, we compared S1 responses to A fiber skin afferent stimulation and A + C skin afferent fiber stimulation in lightly anaesthetized male rats at postnatal day (P)7, P14, P21, and P30. Differences in S1 activity following A and A + C fiber stimulation changed dramatically over this period. At P30, A + C fiber stimulation evoked significantly larger γ, β, and α energy increases compared with A fiber stimulation alone. At younger ages, the changes in S1 oscillatory activity evoked by the two afferent volleys were not significantly different. Silencing TRPV1+ C fibers with QX-314 significantly reduced the γ and β S1 oscillatory energy increases evoked by A + C fibers, at P30 and P21, but not at younger ages. Thus, C fibers differentially modulate S1 oscillatory activity only from the third postnatal week, well after the functional maturation of the somatosensory cortex. This age-related change in afferent evoked S1 oscillatory activity may underpin the maturation of sensory discrimination in the developing brain. Society for Neuroscience 2020-10-07 /pmc/articles/PMC7545434/ /pubmed/32759177 http://dx.doi.org/10.1523/ENEURO.0036-20.2020 Text en Copyright © 2020 Chang et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
spellingShingle Research Article: New Research
Chang, Pishan
Fabrizi, Lorenzo
Fitzgerald, Maria
Distinct Age-Dependent C Fiber-Driven Oscillatory Activity in the Rat Somatosensory Cortex
title Distinct Age-Dependent C Fiber-Driven Oscillatory Activity in the Rat Somatosensory Cortex
title_full Distinct Age-Dependent C Fiber-Driven Oscillatory Activity in the Rat Somatosensory Cortex
title_fullStr Distinct Age-Dependent C Fiber-Driven Oscillatory Activity in the Rat Somatosensory Cortex
title_full_unstemmed Distinct Age-Dependent C Fiber-Driven Oscillatory Activity in the Rat Somatosensory Cortex
title_short Distinct Age-Dependent C Fiber-Driven Oscillatory Activity in the Rat Somatosensory Cortex
title_sort distinct age-dependent c fiber-driven oscillatory activity in the rat somatosensory cortex
topic Research Article: New Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7545434/
https://www.ncbi.nlm.nih.gov/pubmed/32759177
http://dx.doi.org/10.1523/ENEURO.0036-20.2020
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