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Midbrain local circuits shape sound intensity codes

Hierarchical processing of sensory information requires interaction at multiple levels along the peripheral to central pathway. Recent evidence suggests that interaction between driving and modulating components can shape both top down and bottom up processing of sensory information. Here we show th...

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Autores principales: Grimsley, Calum Alex, Sanchez, Jason Tait, Sivaramakrishnan, Shobhana
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3812908/
https://www.ncbi.nlm.nih.gov/pubmed/24198763
http://dx.doi.org/10.3389/fncir.2013.00174
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author Grimsley, Calum Alex
Sanchez, Jason Tait
Sivaramakrishnan, Shobhana
author_facet Grimsley, Calum Alex
Sanchez, Jason Tait
Sivaramakrishnan, Shobhana
author_sort Grimsley, Calum Alex
collection PubMed
description Hierarchical processing of sensory information requires interaction at multiple levels along the peripheral to central pathway. Recent evidence suggests that interaction between driving and modulating components can shape both top down and bottom up processing of sensory information. Here we show that a component inherited from extrinsic sources combines with local components to code sound intensity. By applying high concentrations of divalent cations to neurons in the nucleus of the inferior colliculus in the auditory midbrain, we show that as sound intensity increases, the source of synaptic efficacy changes from inherited inputs to local circuits. In neurons with a wide dynamic range response to intensity, inherited inputs increase firing rates at low sound intensities but saturate at mid-to-high intensities. Local circuits activate at high sound intensities and widen dynamic range by continuously increasing their output gain with intensity. Inherited inputs are necessary and sufficient to evoke tuned responses, however local circuits change peak output. Push–pull driving inhibition and excitation create net excitatory drive to intensity-variant neurons and tune neurons to intensity. Our results reveal that dynamic range and tuning re-emerge in the auditory midbrain through local circuits that are themselves variable or tuned.
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spelling pubmed-38129082013-11-06 Midbrain local circuits shape sound intensity codes Grimsley, Calum Alex Sanchez, Jason Tait Sivaramakrishnan, Shobhana Front Neural Circuits Neuroscience Hierarchical processing of sensory information requires interaction at multiple levels along the peripheral to central pathway. Recent evidence suggests that interaction between driving and modulating components can shape both top down and bottom up processing of sensory information. Here we show that a component inherited from extrinsic sources combines with local components to code sound intensity. By applying high concentrations of divalent cations to neurons in the nucleus of the inferior colliculus in the auditory midbrain, we show that as sound intensity increases, the source of synaptic efficacy changes from inherited inputs to local circuits. In neurons with a wide dynamic range response to intensity, inherited inputs increase firing rates at low sound intensities but saturate at mid-to-high intensities. Local circuits activate at high sound intensities and widen dynamic range by continuously increasing their output gain with intensity. Inherited inputs are necessary and sufficient to evoke tuned responses, however local circuits change peak output. Push–pull driving inhibition and excitation create net excitatory drive to intensity-variant neurons and tune neurons to intensity. Our results reveal that dynamic range and tuning re-emerge in the auditory midbrain through local circuits that are themselves variable or tuned. Frontiers Media S.A. 2013-10-30 /pmc/articles/PMC3812908/ /pubmed/24198763 http://dx.doi.org/10.3389/fncir.2013.00174 Text en Copyright © 2013 Grimsley, Sanchez and Sivaramakrishnan. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Grimsley, Calum Alex
Sanchez, Jason Tait
Sivaramakrishnan, Shobhana
Midbrain local circuits shape sound intensity codes
title Midbrain local circuits shape sound intensity codes
title_full Midbrain local circuits shape sound intensity codes
title_fullStr Midbrain local circuits shape sound intensity codes
title_full_unstemmed Midbrain local circuits shape sound intensity codes
title_short Midbrain local circuits shape sound intensity codes
title_sort midbrain local circuits shape sound intensity codes
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3812908/
https://www.ncbi.nlm.nih.gov/pubmed/24198763
http://dx.doi.org/10.3389/fncir.2013.00174
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