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Universidade do Rio Grande do Norte

1. Figuerola, Wilfredo Blanco. Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional .

Degree: 2012, Universidade do Rio Grande do Norte

Several research lines show that sleep favors memory consolidation and learning. It has been proposed that the cognitive role of sleep is derived from a global scaling of synaptic weights, able to homeostatically restore the ability to learn new things, erasing memories overnight. This phenomenon is typical of slow-wave sleep (SWS) and characterized by non-Hebbian mechanisms, i.e., mechanisms independent of synchronous neuronal activity. Another view holds that sleep also triggers the specific enhancement of synaptic connections, carrying out the embossing of certain mnemonic traces within a lattice of synaptic weights rescaled each night. Such an embossing is understood as the combination of Hebbian and non-Hebbian mechanisms, capable of increasing and decreasing respectively the synaptic weights in complementary circuits, leading to selective memory improvement and a restructuring of synaptic configuration (SC) that can be crucial for the generation of new behaviors ( insights ). The empirical findings indicate that initiation of Hebbian plasticity during sleep occurs in the transition of the SWS to the stage of rapid eye movement (REM), possibly due to the significant differences between the firing rates regimes of the stages and the up-regulation of factors involved in longterm synaptic plasticity. In this study the theories of homeostasis and embossing were compared using an artificial neural network (ANN) fed with action potentials recorded in the hippocampus of rats during the sleep-wake cycle. In the simulation in which the ANN did not apply the long-term plasticity mechanisms during sleep (SWS-transition REM), the synaptic weights distribution was re-scaled inexorably, for its mean value proportional to the input firing rate, erasing the synaptic weights pattern that had been established initially. In contrast, when the long-term plasticity is modeled during the transition SWSREM, an increase of synaptic weights were observed in the range of initial/low values, redistributing effectively the weights in a way to reinforce a subset of synapses over time. The results suggest that a positive regulation coming from the long-term plasticity can completely change the role of sleep: its absence leads to forgetting; its presence leads to a positive mnemonic change Advisors/Committee Members: Dória Neto, Adrião Duarte (advisor), CPF:10749896434 (advisor), http://lattes.cnpq.br/1987295209521433 (advisor), Ribeiro, Sidarta Tollendal Gomes (advisor), CPF:50591797100 (advisor), http://lattes.cnpq.br/0649912135067700 (advisor).

Subjects/Keywords: sono; memoria; pesos sinápticos; rede neural; entalhamento; homeostase; sleep; memory; synaptic weights; artificial neural network; embossing; homeostasis

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Figuerola, W. B. (2012). Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional . (Doctoral Dissertation). Universidade do Rio Grande do Norte. Retrieved from http://repositorio.ufrn.br/handle/123456789/15187

Chicago Manual of Style (16th Edition):

Figuerola, Wilfredo Blanco. “Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional .” 2012. Doctoral Dissertation, Universidade do Rio Grande do Norte. Accessed March 07, 2021. http://repositorio.ufrn.br/handle/123456789/15187.

MLA Handbook (7th Edition):

Figuerola, Wilfredo Blanco. “Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional .” 2012. Web. 07 Mar 2021.

Vancouver:

Figuerola WB. Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional . [Internet] [Doctoral dissertation]. Universidade do Rio Grande do Norte; 2012. [cited 2021 Mar 07]. Available from: http://repositorio.ufrn.br/handle/123456789/15187.

Council of Science Editors:

Figuerola WB. Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional . [Doctoral Dissertation]. Universidade do Rio Grande do Norte; 2012. Available from: http://repositorio.ufrn.br/handle/123456789/15187


Universidade do Rio Grande do Norte

2. Figuerola, Wilfredo Blanco. Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional .

Degree: 2012, Universidade do Rio Grande do Norte

Several research lines show that sleep favors memory consolidation and learning. It has been proposed that the cognitive role of sleep is derived from a global scaling of synaptic weights, able to homeostatically restore the ability to learn new things, erasing memories overnight. This phenomenon is typical of slow-wave sleep (SWS) and characterized by non-Hebbian mechanisms, i.e., mechanisms independent of synchronous neuronal activity. Another view holds that sleep also triggers the specific enhancement of synaptic connections, carrying out the embossing of certain mnemonic traces within a lattice of synaptic weights rescaled each night. Such an embossing is understood as the combination of Hebbian and non-Hebbian mechanisms, capable of increasing and decreasing respectively the synaptic weights in complementary circuits, leading to selective memory improvement and a restructuring of synaptic configuration (SC) that can be crucial for the generation of new behaviors ( insights ). The empirical findings indicate that initiation of Hebbian plasticity during sleep occurs in the transition of the SWS to the stage of rapid eye movement (REM), possibly due to the significant differences between the firing rates regimes of the stages and the up-regulation of factors involved in longterm synaptic plasticity. In this study the theories of homeostasis and embossing were compared using an artificial neural network (ANN) fed with action potentials recorded in the hippocampus of rats during the sleep-wake cycle. In the simulation in which the ANN did not apply the long-term plasticity mechanisms during sleep (SWS-transition REM), the synaptic weights distribution was re-scaled inexorably, for its mean value proportional to the input firing rate, erasing the synaptic weights pattern that had been established initially. In contrast, when the long-term plasticity is modeled during the transition SWSREM, an increase of synaptic weights were observed in the range of initial/low values, redistributing effectively the weights in a way to reinforce a subset of synapses over time. The results suggest that a positive regulation coming from the long-term plasticity can completely change the role of sleep: its absence leads to forgetting; its presence leads to a positive mnemonic change Advisors/Committee Members: Dória Neto, Adrião Duarte (advisor), CPF:10749896434 (advisor), http://lattes.cnpq.br/1987295209521433 (advisor), Ribeiro, Sidarta Tollendal Gomes (advisor), CPF:50591797100 (advisor), http://lattes.cnpq.br/0649912135067700 (advisor).

Subjects/Keywords: sono; memoria; pesos sinápticos; rede neural; entalhamento; homeostase; sleep; memory; synaptic weights; artificial neural network; embossing; homeostasis

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Figuerola, W. B. (2012). Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional . (Thesis). Universidade do Rio Grande do Norte. Retrieved from http://repositorio.ufrn.br/handle/123456789/15187

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Figuerola, Wilfredo Blanco. “Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional .” 2012. Thesis, Universidade do Rio Grande do Norte. Accessed March 07, 2021. http://repositorio.ufrn.br/handle/123456789/15187.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Figuerola, Wilfredo Blanco. “Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional .” 2012. Web. 07 Mar 2021.

Vancouver:

Figuerola WB. Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional . [Internet] [Thesis]. Universidade do Rio Grande do Norte; 2012. [cited 2021 Mar 07]. Available from: http://repositorio.ufrn.br/handle/123456789/15187.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Figuerola WB. Dinâmica da Plasticidade Sináptica em neurônios do hipocampo durante ciclos de sono: um estudo computacional . [Thesis]. Universidade do Rio Grande do Norte; 2012. Available from: http://repositorio.ufrn.br/handle/123456789/15187

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

3. Adrian, Frank Alan. Exact ensemble dynamics for spike-timing-dependent plasticity.

Degree: MS, 2008, Oregon Health Sciences University

Subjects/Keywords: Synapses; Fokker-Planck equation; Hebbian plasticity; synaptic weights; stochastic approaches; Kramers-Moyal expansion

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Adrian, F. A. (2008). Exact ensemble dynamics for spike-timing-dependent plasticity. (Thesis). Oregon Health Sciences University. Retrieved from doi:10.6083/M4SQ8XCB ; http://digitalcommons.ohsu.edu/etd/342

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Adrian, Frank Alan. “Exact ensemble dynamics for spike-timing-dependent plasticity.” 2008. Thesis, Oregon Health Sciences University. Accessed March 07, 2021. doi:10.6083/M4SQ8XCB ; http://digitalcommons.ohsu.edu/etd/342.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Adrian, Frank Alan. “Exact ensemble dynamics for spike-timing-dependent plasticity.” 2008. Web. 07 Mar 2021.

Vancouver:

Adrian FA. Exact ensemble dynamics for spike-timing-dependent plasticity. [Internet] [Thesis]. Oregon Health Sciences University; 2008. [cited 2021 Mar 07]. Available from: doi:10.6083/M4SQ8XCB ; http://digitalcommons.ohsu.edu/etd/342.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Adrian FA. Exact ensemble dynamics for spike-timing-dependent plasticity. [Thesis]. Oregon Health Sciences University; 2008. Available from: doi:10.6083/M4SQ8XCB ; http://digitalcommons.ohsu.edu/etd/342

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.