Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais
Aging is associated with decreasing brain plasticity, especially after the closure of the critical periods of plasticity (a sensitive limited period in life of elevated brain plasticity). Some brain regions may be particularly affected by aging, such as prefrontal cortex (PFC), which has a key role...
| Autor principal: | RODRIGUES, Klebson de Jesus Araujo |
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| Grau: | Tese |
| Idioma: | por |
| Publicado em: |
Universidade Federal do Pará
2017
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http://repositorio.ufpa.br/jspui/handle/2011/8779 |
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ir-2011-87792017-10-16T11:38:40Z Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais RODRIGUES, Klebson de Jesus Araujo PEREIRA JÚNIOR, Antônio http://lattes.cnpq.br/1402289786010170 BAHIA, Carlomagno Pacheco http://lattes.cnpq.br/0910507988777644 Neurociência Neurofisiologia Neuroplasticidade Córtex pré-frontal Redes perineuronais Matriz extracelular Funções executivas CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA::FISIOLOGIA GERAL::NEUROFISIOLOGIA Aging is associated with decreasing brain plasticity, especially after the closure of the critical periods of plasticity (a sensitive limited period in life of elevated brain plasticity). Some brain regions may be particularly affected by aging, such as prefrontal cortex (PFC), which has a key role in the organization of higherorder cognitive aspects, the executive functions, including attention, set-shifting, working memory, decision making, etc. Decline of plasticity in the PFC and the brain is attributed mainly to the appearance of a structure called perineuronal net (PNNs) which enwraps the cell body and dendrites of many classes of neurons. PNNs are extracellular matrix structures consisting of chondroitin sulfate proteoglycans, hyaluronan, link proteins and tenascin, and are involved in the control of experience-dependent cortical plasticity and the closure of critical periods. Degradation of PNNs with the enzyme Chondroitinase ABC (ChABC) restores juvenile forms of plasticity in the adult brain. Here, we examined the developmental time course of PNN formation in the medial PFC (mPFC) of male rats ranging in age from the seventh postnatal day (PND) to 11 months. We used the lectin Vicia villosa agglutinin that binds to glycosaminoglycan chains present in the PNNs. We also investigated whether the digestion of PNNs by bilateral injection of ChABC in the mPFC may open a new window of increased plasticity in adult rats, evaluated by two executive function tests: object recognition and spontaneous alternation. We found that immature PNNs were observed in PND 20 animals, but mature PNNs were seen only after PND 75-90 and a mature form appeared around 5 months of age. In addition, our results showed that enzymatic PNN removal promoted a significant increase in performance in the ChABC-treated animals in both behavioral tests. The present study reveals for the first time the temporal development of PNN formation in the rat mPFC. We also show that the degradation of PNNs with ChABC not only promotes plasticity but also potentiates cognitive abilities in adult animals. CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico No processo de envelhecimento, há uma diminuição natural na plasticidade no Sistema Nervoso Central (SNC). Algumas regiões cerebrais podem ser particularmente afetadas pelo envelhecimento, como o córtex pré-frontal (CPF), que possui um papel fundamental nas funções executivas, incluindo atenção, flexibilidade cognitiva, memória de trabalho, tomada de decisão, etc. O declínio na plasticidade do CPF e do SNC como um todo pode ser atribuído principalmente pelo aparecimento de estruturas chamadas redes perineurais (RPNs) que envelopam o corpo celular e dendritos de classes específicas de neurônios. As RPNs são estruturas de matriz extracelular consistindo de proteoglicanos de sulfato de condroitina, ácido hialurônico, proteínas de ligação e tenascina, e estão envolvidos no controle da plasticidade cortical e também no encerramento do período crítico. Contudo, têm-se mostrado que a degradação das RPNs pela enzima Condroitinase ABC (ChABC) restaura formas juvenis de plasticidade no cérebro adulto por liberar os freios da plasticidade. O objetivo do presente trabalho é caracterizar o curso temporal da formação e desenvolvimento das RPNs no córtex pré-frontal medial (CPFm) de ratos. As RPNs foram marcadas com a lecitina Vicia villosa, que se liga a cadeias de glicosaminoglicanos presentes nas RPNs. Além disso, verificamos se a digestão localizada das RPNs no CPFm através da injeção de ChABC é capaz de abrir um novo período crítico de plasticidade e facilitar o desempenho em testes de função executiva (memória operacional). Os resultados mostraram que as RPNs no CPFm começam a surgir aos 20 DPN e amadurecem progressivamente até os 75-90 DPN. Formas exclusiamente maduras de RPNs foram observadas em animais com 5 meses de idade. Além disso, os resultados mostraram que a remoção enzimática das RPNs com ChABC promoveu melhoras no aprendizado dos testes de função executiva. 2017-07-04T14:15:21Z 2017-07-04T14:15:21Z 2016-11-01 Tese RODRIGUES, Klebson de Jesus Araújo. Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais. 2016. 46 f. Tese (Doutorado) - Universidade Federal do Pará, Instituto de Ciências Biológicas, Belém, 2016. Programa de Pós-graduação em Neurociências e Biologia Celular. http://repositorio.ufpa.br/jspui/handle/2011/8779 por Acesso Aberto application/pdf Universidade Federal do Pará Brasil Instituto de Ciências Biológicas UFPA Programa de Pós-Graduação em Neurociências e Biologia Celular |
| institution |
Repositório Institucional - Universidade Federal do Pará |
| collection |
RI-UFPA |
| language |
por |
| topic |
Neurociência Neurofisiologia Neuroplasticidade Córtex pré-frontal Redes perineuronais Matriz extracelular Funções executivas CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA::FISIOLOGIA GERAL::NEUROFISIOLOGIA |
| spellingShingle |
Neurociência Neurofisiologia Neuroplasticidade Córtex pré-frontal Redes perineuronais Matriz extracelular Funções executivas CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA::FISIOLOGIA GERAL::NEUROFISIOLOGIA RODRIGUES, Klebson de Jesus Araujo Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais |
| topic_facet |
Neurociência Neurofisiologia Neuroplasticidade Córtex pré-frontal Redes perineuronais Matriz extracelular Funções executivas CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA::FISIOLOGIA GERAL::NEUROFISIOLOGIA |
| description |
Aging is associated with decreasing brain plasticity, especially after the closure of the critical periods of plasticity (a sensitive limited period in life of elevated brain plasticity). Some brain regions may be particularly affected by aging, such as prefrontal cortex (PFC), which has a key role in the organization of higherorder cognitive aspects, the executive functions, including attention, set-shifting, working memory, decision making, etc. Decline of plasticity in the PFC and the brain is attributed mainly to the appearance of a structure called perineuronal net (PNNs) which enwraps the cell body and dendrites of many classes of neurons. PNNs are extracellular matrix structures consisting of chondroitin sulfate proteoglycans, hyaluronan, link proteins and tenascin, and are involved in the control of experience-dependent cortical plasticity and the closure of critical periods. Degradation of PNNs with the enzyme Chondroitinase ABC (ChABC) restores juvenile forms of plasticity in the adult brain. Here, we examined the developmental time course of PNN formation in the medial PFC (mPFC) of male rats ranging in age from the seventh postnatal day (PND) to 11 months. We used the lectin Vicia villosa agglutinin that binds to glycosaminoglycan chains present in the PNNs. We also investigated whether the digestion of PNNs by bilateral injection of ChABC in the mPFC may open a new window of increased plasticity in adult rats, evaluated by two executive function tests: object recognition and spontaneous alternation. We found that immature PNNs were observed in PND 20 animals, but mature PNNs were seen only after PND 75-90 and a mature form appeared around 5 months of age. In addition, our results showed that enzymatic PNN removal promoted a significant increase in performance in the ChABC-treated animals in both behavioral tests. The present study reveals for the first time the temporal development of PNN formation in the rat mPFC. We also show that the degradation of PNNs with ChABC not only promotes plasticity but also potentiates cognitive abilities in adult animals. |
| author_additional |
PEREIRA JÚNIOR, Antônio |
| author_additionalStr |
PEREIRA JÚNIOR, Antônio |
| format |
Tese |
| author |
RODRIGUES, Klebson de Jesus Araujo |
| title |
Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais |
| title_short |
Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais |
| title_full |
Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais |
| title_fullStr |
Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais |
| title_full_unstemmed |
Plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais |
| title_sort |
plasticidade aumentada no córtex pré-frontal de ratos com a remoção de redes perineuronais |
| publisher |
Universidade Federal do Pará |
| publishDate |
2017 |
| url |
http://repositorio.ufpa.br/jspui/handle/2011/8779 |
| _version_ |
1787149017679921152 |
| score |
11.687526 |