Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers

Detalhes bibliográficos
Autor(a) principal: FERNANDES-DE-LIMA,VERA M.
Data de Publicação: 2001
Outros Autores: KOGLER,JOÃO E., BENNATON,JOCELYN, HANKE,WOLFGANG
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Anais da Academia Brasileira de Ciências (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000300006
Resumo: The brain is an excitable media in which excitation waves propagate at several scales of time and space. ''One-dimensional'' action potentials (millisecond scale) along the axon membrane, and spreading depression waves (seconds to minutes) at the three dimensions of the gray matter neuropil (complex of interacting membranes) are examples of excitation waves. In the retina, excitation waves have a prominent intrinsic optical signal (IOS). This optical signal is created by light scatter and has different components at the red and blue end of the spectrum. We could observe the wave onset in the retina, and measure the optical changes at the critical transition from quiescence to propagating wave. The results demonstrated the presence of fluctuations preceding propagation and suggested a phase transition. We have interpreted these results based on an extrapolation from Tasaki's experiments with action potentials and volume phase transitions of polymers. Thus, the scatter of red light appeared to be a volume phase transition in the extracellular matrix that was caused by the interactions between the cellular membrane cell coat and the extracellular sugar and protein complexes. If this hypothesis were correct, then forcing extracellular current flow should create a similar signal in another tissue, provided that this tissue was also transparent to light and with a similarly narrow extracellular space. This control tissue exists and it is the crystalline lens. We performed the experiments and confirmed the optical changes. Phase transitions in the extracellular polymers could be an important part of the long-range correlations found during wave propagation in central nervous tissue.
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spelling Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymersintrinsic optic signalsvolume phase transitionspolymersspreading depressioncentral gray matterextracellular matrixThe brain is an excitable media in which excitation waves propagate at several scales of time and space. ''One-dimensional'' action potentials (millisecond scale) along the axon membrane, and spreading depression waves (seconds to minutes) at the three dimensions of the gray matter neuropil (complex of interacting membranes) are examples of excitation waves. In the retina, excitation waves have a prominent intrinsic optical signal (IOS). This optical signal is created by light scatter and has different components at the red and blue end of the spectrum. We could observe the wave onset in the retina, and measure the optical changes at the critical transition from quiescence to propagating wave. The results demonstrated the presence of fluctuations preceding propagation and suggested a phase transition. We have interpreted these results based on an extrapolation from Tasaki's experiments with action potentials and volume phase transitions of polymers. Thus, the scatter of red light appeared to be a volume phase transition in the extracellular matrix that was caused by the interactions between the cellular membrane cell coat and the extracellular sugar and protein complexes. If this hypothesis were correct, then forcing extracellular current flow should create a similar signal in another tissue, provided that this tissue was also transparent to light and with a similarly narrow extracellular space. This control tissue exists and it is the crystalline lens. We performed the experiments and confirmed the optical changes. Phase transitions in the extracellular polymers could be an important part of the long-range correlations found during wave propagation in central nervous tissue.Academia Brasileira de Ciências2001-09-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000300006Anais da Academia Brasileira de Ciências v.73 n.3 2001reponame:Anais da Academia Brasileira de Ciências (Online)instname:Academia Brasileira de Ciências (ABC)instacron:ABC10.1590/S0001-37652001000300006info:eu-repo/semantics/openAccessFERNANDES-DE-LIMA,VERA M.KOGLER,JOÃO E.BENNATON,JOCELYNHANKE,WOLFGANGeng2001-10-05T00:00:00Zoai:scielo:S0001-37652001000300006Revistahttp://www.scielo.br/aabchttps://old.scielo.br/oai/scielo-oai.php||aabc@abc.org.br1678-26900001-3765opendoar:2001-10-05T00:00Anais da Academia Brasileira de Ciências (Online) - Academia Brasileira de Ciências (ABC)false
dc.title.none.fl_str_mv Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
title Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
spellingShingle Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
FERNANDES-DE-LIMA,VERA M.
intrinsic optic signals
volume phase transitions
polymers
spreading depression
central gray matter
extracellular matrix
title_short Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
title_full Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
title_fullStr Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
title_full_unstemmed Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
title_sort Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers
author FERNANDES-DE-LIMA,VERA M.
author_facet FERNANDES-DE-LIMA,VERA M.
KOGLER,JOÃO E.
BENNATON,JOCELYN
HANKE,WOLFGANG
author_role author
author2 KOGLER,JOÃO E.
BENNATON,JOCELYN
HANKE,WOLFGANG
author2_role author
author
author
dc.contributor.author.fl_str_mv FERNANDES-DE-LIMA,VERA M.
KOGLER,JOÃO E.
BENNATON,JOCELYN
HANKE,WOLFGANG
dc.subject.por.fl_str_mv intrinsic optic signals
volume phase transitions
polymers
spreading depression
central gray matter
extracellular matrix
topic intrinsic optic signals
volume phase transitions
polymers
spreading depression
central gray matter
extracellular matrix
description The brain is an excitable media in which excitation waves propagate at several scales of time and space. ''One-dimensional'' action potentials (millisecond scale) along the axon membrane, and spreading depression waves (seconds to minutes) at the three dimensions of the gray matter neuropil (complex of interacting membranes) are examples of excitation waves. In the retina, excitation waves have a prominent intrinsic optical signal (IOS). This optical signal is created by light scatter and has different components at the red and blue end of the spectrum. We could observe the wave onset in the retina, and measure the optical changes at the critical transition from quiescence to propagating wave. The results demonstrated the presence of fluctuations preceding propagation and suggested a phase transition. We have interpreted these results based on an extrapolation from Tasaki's experiments with action potentials and volume phase transitions of polymers. Thus, the scatter of red light appeared to be a volume phase transition in the extracellular matrix that was caused by the interactions between the cellular membrane cell coat and the extracellular sugar and protein complexes. If this hypothesis were correct, then forcing extracellular current flow should create a similar signal in another tissue, provided that this tissue was also transparent to light and with a similarly narrow extracellular space. This control tissue exists and it is the crystalline lens. We performed the experiments and confirmed the optical changes. Phase transitions in the extracellular polymers could be an important part of the long-range correlations found during wave propagation in central nervous tissue.
publishDate 2001
dc.date.none.fl_str_mv 2001-09-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000300006
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000300006
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S0001-37652001000300006
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Academia Brasileira de Ciências
publisher.none.fl_str_mv Academia Brasileira de Ciências
dc.source.none.fl_str_mv Anais da Academia Brasileira de Ciências v.73 n.3 2001
reponame:Anais da Academia Brasileira de Ciências (Online)
instname:Academia Brasileira de Ciências (ABC)
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reponame_str Anais da Academia Brasileira de Ciências (Online)
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