Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia
Autor(a) principal: | |
---|---|
Data de Publicação: | 2013 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFRN |
Texto Completo: | https://repositorio.ufrn.br/jspui/handle/123456789/17028 |
Resumo: | Processing in the visual system starts in the retina. Its complex network of cells with different properties enables for parallel encoding and transmission of visual information to the lateral geniculate nucleus (LGN) and to the cortex. In the retina, it has been shown that responses are often accompanied by fast synchronous oscillations (30 - 90 Hz) in a stimulus-dependent manner. Studies in the frog, rabbit, cat and monkey, have shown strong oscillatory responses to large stimuli which probably encode global stimulus properties, such as size and continuity (Neuenschwander and Singer, 1996; Ishikane et al., 2005). Moreover, simultaneous recordings from different levels in the visual system have demonstrated that the oscillatory patterning of retinal ganglion cell responses are transmitted to the cortex via the LGN (Castelo-Branco et al., 1998). Overall these results suggest that feedforward synchronous oscillations contribute to visual encoding. In the present study on the LGN of the anesthetized cat, we further investigate the role of retinal oscillations in visual processing by applying complex stimuli, such as natural visual scenes, light spots of varying size and contrast, and flickering checkerboards. This is a necessary step for understanding encoding mechanisms in more naturalistic conditions, as currently most data on retinal oscillations have been limited to simple, flashed and stationary stimuli. Correlation analysis of spiking responses confirmed previous results showing that oscillatory responses in the retina (observed here from the LGN responses) largely depend on the size and stationarity of the stimulus. For natural scenes (gray-level and binary movies) oscillations appeared only for brief moments probably when receptive fields were dominated by large continuous, flat-contrast surfaces. Moreover, oscillatory responses to a circle stimulus could be broken with an annular mask indicating that synchronization arises from relatively local interactions among populations of activated cells in the retina. A surprising finding in this study was that retinal oscillations are highly dependent on halothane anesthesia levels. In the absence of halothane, oscillatory activity vanished independent of the characteristics of the stimuli. The same results were obtained for isoflurane, which has similar pharmacological properties. These new and unexpected findings question whether feedfoward oscillations in the early visual system are simply due to an imbalance between excitation and inhibition in the retinal networks generated by the halogenated anesthetics. Further studies in awake behaving animals are necessary to extend these conclusions |
id |
UFRN_f70c9c6625aed6e024459527ee3389c1 |
---|---|
oai_identifier_str |
oai:https://repositorio.ufrn.br:123456789/17028 |
network_acronym_str |
UFRN |
network_name_str |
Repositório Institucional da UFRN |
repository_id_str |
|
spelling |
Freitag, Fábio Batistahttp://lattes.cnpq.br/2623443946046050http://lattes.cnpq.br/9217956361436464Tort, Adriano Bretanha Lopeshttp://lattes.cnpq.br/3181888189086405Baron, Jerome Paul Armand LaurentNeuenschwander, Sergio2014-12-17T15:28:53Z2014-02-252014-12-17T15:28:53Z2013-08-27FREITAG, Fábio Batista. Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia. 2013. 60 f. Dissertação (Mestrado em Neurobiologia Celular e Molecular; Neurobiologia de Sistemas e Cognição; Neurocomputação Neuroengen) - Universidade Federal do Rio Grande do Norte, Natal, 2013.https://repositorio.ufrn.br/jspui/handle/123456789/17028Processing in the visual system starts in the retina. Its complex network of cells with different properties enables for parallel encoding and transmission of visual information to the lateral geniculate nucleus (LGN) and to the cortex. In the retina, it has been shown that responses are often accompanied by fast synchronous oscillations (30 - 90 Hz) in a stimulus-dependent manner. Studies in the frog, rabbit, cat and monkey, have shown strong oscillatory responses to large stimuli which probably encode global stimulus properties, such as size and continuity (Neuenschwander and Singer, 1996; Ishikane et al., 2005). Moreover, simultaneous recordings from different levels in the visual system have demonstrated that the oscillatory patterning of retinal ganglion cell responses are transmitted to the cortex via the LGN (Castelo-Branco et al., 1998). Overall these results suggest that feedforward synchronous oscillations contribute to visual encoding. In the present study on the LGN of the anesthetized cat, we further investigate the role of retinal oscillations in visual processing by applying complex stimuli, such as natural visual scenes, light spots of varying size and contrast, and flickering checkerboards. This is a necessary step for understanding encoding mechanisms in more naturalistic conditions, as currently most data on retinal oscillations have been limited to simple, flashed and stationary stimuli. Correlation analysis of spiking responses confirmed previous results showing that oscillatory responses in the retina (observed here from the LGN responses) largely depend on the size and stationarity of the stimulus. For natural scenes (gray-level and binary movies) oscillations appeared only for brief moments probably when receptive fields were dominated by large continuous, flat-contrast surfaces. Moreover, oscillatory responses to a circle stimulus could be broken with an annular mask indicating that synchronization arises from relatively local interactions among populations of activated cells in the retina. A surprising finding in this study was that retinal oscillations are highly dependent on halothane anesthesia levels. In the absence of halothane, oscillatory activity vanished independent of the characteristics of the stimuli. The same results were obtained for isoflurane, which has similar pharmacological properties. These new and unexpected findings question whether feedfoward oscillations in the early visual system are simply due to an imbalance between excitation and inhibition in the retinal networks generated by the halogenated anesthetics. Further studies in awake behaving animals are necessary to extend these conclusionsO processamento da informação visual se inicia na retina. A sua complexa rede de células com diferentes propriedades permite que a informação visual seja codificada em canais paralelos e transmitida para o núcleo geniculado lateral (LGN) e o córtex. Na retina, tais respostas estão frequentemente acompanhadas por oscilações sincronizadas de alta frequência (30 90 Hz) em uma maneira dependente do estímulo. Como demonstrado em estudos na rã, coelho, gato e macaco, respostas oscilatórias ocorrem em geral a estímulos relativamente grandes, podendo codificar propriedades globais do estímulo como o tamanho e continuidade (Neuenschwander and Singer, 1996; Ishikane et al., 2005). Além disso, registros simultâneos em diferentes níveis do sistema visual têm mostrado que o padrão de oscilação nas células ganglionares retinianas é transmitido para o córtex visual via LGN (Castelo-Branco et al., 1998). De uma forma geral, esses resultados sugerem que oscilações sincronizadas em uma maneira feedforward são importantes na codificação da informação visual. No presente estudo feito no LGN de gatos anestesiados, investigamos o papel das oscilações retinianas no processamento de informação visual através da apresentação de estímulos complexos, como cenas naturais, pixels aleatórios no tempo e espaço, além de grades em movimento. Esse é um importante passo para o entendimento de mecanismos de codificação em condições naturais, já que grande parte dos estudos que investigaram o papel de oscilações retinianas utilizaram-se de estímulos simples e estacionários. Análises de correlação de respostas neuronais (spiking responses) confirmaram resultados prévios mostrando que respostas oscilatórias na retina (observadas aqui a partir de registros no LGN) dependem do tamanho e estacionariedade do estímulo. Para filmes de cenas naturais (em escala de cinza e preto e branco) oscilações apareceram apenas por breves momentos provavelmente quando os campos receptores foram dominados por padrões extensos e contínuos (para ambas as escalas). As atividades oscilatórias parecem ser dependentes de uma massa crítica de células ativadas sugerindo que esse padrão regular de atividade surge através de interações horizontais na retina. Nossos resultados mostram, além disto, que surpreendentemente oscilações da retina no gato são dependentes da anestesia mediada por halotano. Na ausência deste, atividades oscilatórias estiveram ausentes independentemente das características dos estímulos visuais. Resultados semelhantes foram obtidos para o isoflurano, anestésico com propriedades farmacológicas similares. Esse novo e inesperado resultado nos faz questionar se oscilações feedforward no sistema visual não seriam resultado de um desequilíbrio entre correntes de excitação e inibição nas redes retinianas gerado pelos anestésicos halogenados. Experimentos futuros em animais acordados serão necessários para confirmar essas conclusõesCoordenação de Aperfeiçoamento de Pessoal de Nível Superiorapplication/pdfporUniversidade Federal do Rio Grande do NortePrograma de Pós-Graduação em NeurocienciasUFRNBRNeurobiologia Celular e Molecular; Neurobiologia de Sistemas e Cognição; Neurocomputação NeuroengenRetina. Oscilação. Sincronização. Halotana. VisãoRetina. Oscillation. Synchronization. Halothane. VisualCNPQ::CIENCIAS DA SAUDE::MEDICINA::CLINICA MEDICA::NEUROLOGIAEncoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesiainfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRNinstname:Universidade Federal do Rio Grande do Norte (UFRN)instacron:UFRNORIGINALFabioBF_DISSERT.pdfapplication/pdf6339300https://repositorio.ufrn.br/bitstream/123456789/17028/1/FabioBF_DISSERT.pdfd864db11d9029d4bcca9a2aaf6e2f131MD51TEXTFabioBF_DISSERT.pdf.txtFabioBF_DISSERT.pdf.txtExtracted texttext/plain120059https://repositorio.ufrn.br/bitstream/123456789/17028/6/FabioBF_DISSERT.pdf.txt1f5ec1fb770b9346724912bfeed3b2c6MD56THUMBNAILFabioBF_DISSERT.pdf.jpgFabioBF_DISSERT.pdf.jpgIM Thumbnailimage/jpeg2353https://repositorio.ufrn.br/bitstream/123456789/17028/7/FabioBF_DISSERT.pdf.jpg22c278996ca7fde3dcc77c0c05c3eeb5MD57123456789/170282017-11-04 09:13:19.255oai:https://repositorio.ufrn.br:123456789/17028Repositório de PublicaçõesPUBhttp://repositorio.ufrn.br/oai/opendoar:2017-11-04T12:13:19Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN)false |
dc.title.por.fl_str_mv |
Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia |
title |
Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia |
spellingShingle |
Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia Freitag, Fábio Batista Retina. Oscilação. Sincronização. Halotana. Visão Retina. Oscillation. Synchronization. Halothane. Visual CNPQ::CIENCIAS DA SAUDE::MEDICINA::CLINICA MEDICA::NEUROLOGIA |
title_short |
Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia |
title_full |
Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia |
title_fullStr |
Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia |
title_full_unstemmed |
Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia |
title_sort |
Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia |
author |
Freitag, Fábio Batista |
author_facet |
Freitag, Fábio Batista |
author_role |
author |
dc.contributor.authorID.por.fl_str_mv |
|
dc.contributor.authorLattes.por.fl_str_mv |
http://lattes.cnpq.br/2623443946046050 |
dc.contributor.advisorID.por.fl_str_mv |
|
dc.contributor.advisorLattes.por.fl_str_mv |
http://lattes.cnpq.br/9217956361436464 |
dc.contributor.referees1.pt_BR.fl_str_mv |
Tort, Adriano Bretanha Lopes |
dc.contributor.referees1ID.por.fl_str_mv |
|
dc.contributor.referees1Lattes.por.fl_str_mv |
http://lattes.cnpq.br/3181888189086405 |
dc.contributor.referees2.pt_BR.fl_str_mv |
Baron, Jerome Paul Armand Laurent |
dc.contributor.referees2ID.por.fl_str_mv |
|
dc.contributor.author.fl_str_mv |
Freitag, Fábio Batista |
dc.contributor.advisor1.fl_str_mv |
Neuenschwander, Sergio |
contributor_str_mv |
Neuenschwander, Sergio |
dc.subject.por.fl_str_mv |
Retina. Oscilação. Sincronização. Halotana. Visão |
topic |
Retina. Oscilação. Sincronização. Halotana. Visão Retina. Oscillation. Synchronization. Halothane. Visual CNPQ::CIENCIAS DA SAUDE::MEDICINA::CLINICA MEDICA::NEUROLOGIA |
dc.subject.eng.fl_str_mv |
Retina. Oscillation. Synchronization. Halothane. Visual |
dc.subject.cnpq.fl_str_mv |
CNPQ::CIENCIAS DA SAUDE::MEDICINA::CLINICA MEDICA::NEUROLOGIA |
description |
Processing in the visual system starts in the retina. Its complex network of cells with different properties enables for parallel encoding and transmission of visual information to the lateral geniculate nucleus (LGN) and to the cortex. In the retina, it has been shown that responses are often accompanied by fast synchronous oscillations (30 - 90 Hz) in a stimulus-dependent manner. Studies in the frog, rabbit, cat and monkey, have shown strong oscillatory responses to large stimuli which probably encode global stimulus properties, such as size and continuity (Neuenschwander and Singer, 1996; Ishikane et al., 2005). Moreover, simultaneous recordings from different levels in the visual system have demonstrated that the oscillatory patterning of retinal ganglion cell responses are transmitted to the cortex via the LGN (Castelo-Branco et al., 1998). Overall these results suggest that feedforward synchronous oscillations contribute to visual encoding. In the present study on the LGN of the anesthetized cat, we further investigate the role of retinal oscillations in visual processing by applying complex stimuli, such as natural visual scenes, light spots of varying size and contrast, and flickering checkerboards. This is a necessary step for understanding encoding mechanisms in more naturalistic conditions, as currently most data on retinal oscillations have been limited to simple, flashed and stationary stimuli. Correlation analysis of spiking responses confirmed previous results showing that oscillatory responses in the retina (observed here from the LGN responses) largely depend on the size and stationarity of the stimulus. For natural scenes (gray-level and binary movies) oscillations appeared only for brief moments probably when receptive fields were dominated by large continuous, flat-contrast surfaces. Moreover, oscillatory responses to a circle stimulus could be broken with an annular mask indicating that synchronization arises from relatively local interactions among populations of activated cells in the retina. A surprising finding in this study was that retinal oscillations are highly dependent on halothane anesthesia levels. In the absence of halothane, oscillatory activity vanished independent of the characteristics of the stimuli. The same results were obtained for isoflurane, which has similar pharmacological properties. These new and unexpected findings question whether feedfoward oscillations in the early visual system are simply due to an imbalance between excitation and inhibition in the retinal networks generated by the halogenated anesthetics. Further studies in awake behaving animals are necessary to extend these conclusions |
publishDate |
2013 |
dc.date.issued.fl_str_mv |
2013-08-27 |
dc.date.accessioned.fl_str_mv |
2014-12-17T15:28:53Z |
dc.date.available.fl_str_mv |
2014-02-25 2014-12-17T15:28:53Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
FREITAG, Fábio Batista. Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia. 2013. 60 f. Dissertação (Mestrado em Neurobiologia Celular e Molecular; Neurobiologia de Sistemas e Cognição; Neurocomputação Neuroengen) - Universidade Federal do Rio Grande do Norte, Natal, 2013. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufrn.br/jspui/handle/123456789/17028 |
identifier_str_mv |
FREITAG, Fábio Batista. Encoding mechanisms based on fast oscillations in the retina of the cat and their dependencies on anesthesia. 2013. 60 f. Dissertação (Mestrado em Neurobiologia Celular e Molecular; Neurobiologia de Sistemas e Cognição; Neurocomputação Neuroengen) - Universidade Federal do Rio Grande do Norte, Natal, 2013. |
url |
https://repositorio.ufrn.br/jspui/handle/123456789/17028 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal do Rio Grande do Norte |
dc.publisher.program.fl_str_mv |
Programa de Pós-Graduação em Neurociencias |
dc.publisher.initials.fl_str_mv |
UFRN |
dc.publisher.country.fl_str_mv |
BR |
dc.publisher.department.fl_str_mv |
Neurobiologia Celular e Molecular; Neurobiologia de Sistemas e Cognição; Neurocomputação Neuroengen |
publisher.none.fl_str_mv |
Universidade Federal do Rio Grande do Norte |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFRN instname:Universidade Federal do Rio Grande do Norte (UFRN) instacron:UFRN |
instname_str |
Universidade Federal do Rio Grande do Norte (UFRN) |
instacron_str |
UFRN |
institution |
UFRN |
reponame_str |
Repositório Institucional da UFRN |
collection |
Repositório Institucional da UFRN |
bitstream.url.fl_str_mv |
https://repositorio.ufrn.br/bitstream/123456789/17028/1/FabioBF_DISSERT.pdf https://repositorio.ufrn.br/bitstream/123456789/17028/6/FabioBF_DISSERT.pdf.txt https://repositorio.ufrn.br/bitstream/123456789/17028/7/FabioBF_DISSERT.pdf.jpg |
bitstream.checksum.fl_str_mv |
d864db11d9029d4bcca9a2aaf6e2f131 1f5ec1fb770b9346724912bfeed3b2c6 22c278996ca7fde3dcc77c0c05c3eeb5 |
bitstream.checksumAlgorithm.fl_str_mv |
MD5 MD5 MD5 |
repository.name.fl_str_mv |
Repositório Institucional da UFRN - Universidade Federal do Rio Grande do Norte (UFRN) |
repository.mail.fl_str_mv |
|
_version_ |
1802117784888410112 |