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The effects of arousal on apical amplification and conscious state

Neocortical pyramidal cells can integrate two classes of input separately and use one to modulate response to the other. Their tuft dendrites are electrotonically separated from basal dendrites and soma by the apical dendrite, and apical hyperpolarization-activated currents (I(h)) further isolate su...

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Autores principales: Phillips, W. A., Larkum, M. E., Harley, C. W., Silverstein, S. M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5934888/
https://www.ncbi.nlm.nih.gov/pubmed/29877512
http://dx.doi.org/10.1093/nc/niw015
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author Phillips, W. A.
Larkum, M. E.
Harley, C. W.
Silverstein, S. M.
author_facet Phillips, W. A.
Larkum, M. E.
Harley, C. W.
Silverstein, S. M.
author_sort Phillips, W. A.
collection PubMed
description Neocortical pyramidal cells can integrate two classes of input separately and use one to modulate response to the other. Their tuft dendrites are electrotonically separated from basal dendrites and soma by the apical dendrite, and apical hyperpolarization-activated currents (I(h)) further isolate subthreshold integration of tuft inputs. When apical depolarization exceeds a threshold, however, it can enhance response to the basal inputs that specify the cell’s selective sensitivity. This process is referred to as apical amplification (AA). We review evidence suggesting that, by regulating I(h) in the apical compartments, adrenergic arousal controls the coupling between apical and somatic integration zones thus modifying cognitive capabilities closely associated with consciousness. Evidence relating AA to schizophrenia, sleep, and anesthesia is reviewed, and we assess theories that emphasize the relevance of AA to consciousness. Implications for theories of neocortical computation that emphasize context-sensitive modulation are summarized. We conclude that the findings concerning AA and its regulation by arousal offer a new perspective on states of consciousness, the function and evolution of neocortex, and psychopathology. Many issues worthy of closer examination arise.
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spelling pubmed-59348882018-06-06 The effects of arousal on apical amplification and conscious state Phillips, W. A. Larkum, M. E. Harley, C. W. Silverstein, S. M. Neurosci Conscious Review Article Neocortical pyramidal cells can integrate two classes of input separately and use one to modulate response to the other. Their tuft dendrites are electrotonically separated from basal dendrites and soma by the apical dendrite, and apical hyperpolarization-activated currents (I(h)) further isolate subthreshold integration of tuft inputs. When apical depolarization exceeds a threshold, however, it can enhance response to the basal inputs that specify the cell’s selective sensitivity. This process is referred to as apical amplification (AA). We review evidence suggesting that, by regulating I(h) in the apical compartments, adrenergic arousal controls the coupling between apical and somatic integration zones thus modifying cognitive capabilities closely associated with consciousness. Evidence relating AA to schizophrenia, sleep, and anesthesia is reviewed, and we assess theories that emphasize the relevance of AA to consciousness. Implications for theories of neocortical computation that emphasize context-sensitive modulation are summarized. We conclude that the findings concerning AA and its regulation by arousal offer a new perspective on states of consciousness, the function and evolution of neocortex, and psychopathology. Many issues worthy of closer examination arise. Oxford University Press 2016-09-11 /pmc/articles/PMC5934888/ /pubmed/29877512 http://dx.doi.org/10.1093/nc/niw015 Text en © The Author 2016. Published by Oxford University Press. http://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
spellingShingle Review Article
Phillips, W. A.
Larkum, M. E.
Harley, C. W.
Silverstein, S. M.
The effects of arousal on apical amplification and conscious state
title The effects of arousal on apical amplification and conscious state
title_full The effects of arousal on apical amplification and conscious state
title_fullStr The effects of arousal on apical amplification and conscious state
title_full_unstemmed The effects of arousal on apical amplification and conscious state
title_short The effects of arousal on apical amplification and conscious state
title_sort effects of arousal on apical amplification and conscious state
topic Review Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5934888/
https://www.ncbi.nlm.nih.gov/pubmed/29877512
http://dx.doi.org/10.1093/nc/niw015
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