Avaliação do efeito do ambiente enriquecido sobre o processo de desmielinização e remielinização
Data
2011-11-23
Autores
Oliveira, Nathalia Serra de 
Orientadores
Castro, Glaucia Monteiro de
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A Esclerose Múltipla (EM) é uma doença neurológica crônica, inflamatória, desmielinizante do
Sistema Nervoso Central (SNC). Para seu estudo diversos modelos vêm sendo utilizados, entre
os quais desmielinização induzida com cuprizona, a qual desencadeia alterações
comportamentais nos animais. Estudos recentes fornecem novos parâmetros sobre a ação do
enriquecimento ambiental e sua relevância para o envelhecimento e doenças
neurodegenerativas. O enriquecimento ambiental é uma condição de habitação para animais
que permite maior estimulação sensorial, motora, social e cognitiva em relação às condiçõespadrão, proporcionando a reorganização funcional dos circuitos neuronais. O presente estudo
tem por objetivo avaliar o processo de desmielinização e neurotoxicidade desencadeado pelo
tratamento com a cuprizona frente à exposição ao ambiente enriquecido. Foram utilizados ratos
da linhagem Lewis, machos com idade de sete semanas. Os animais controle receberam ração
comercial moída e o grupo tratado recebeu ração moída com adição de cuprizona (0,6%) por 4
semanas. Os grupos que passaram por o período de recuperação receberam a ração comercial
normal por mais uma semana, totalizando 5 semanas. Animais pertencentes aos grupos de
ambiente enriquecido foram expostos a sessões diárias de uma hora durante o período
experimental. Na primeira, terceira e última semana do tratamento, os animais foram
submetidos a testes de comportamento e neurotoxicidade. Grupos tratados com cuprizona
apresentam escores de neurotoxicidade significativamente mais elevados (p < 0,001) 15 dias após
início do tratamento. Os resultados do teste Walking Track demonstraram impressão completa e
uniforme das patas dos animais do grupo controle. Por outro lado, a impressão das patas dos
animais tratados apresentou-se errátil e sem uniformidade de caminhada e na distância entre as
pegadas. Animais expostos ao ambiente enriquecido e ao período de recuperação apresentam
impressão uniforme, semelhante aos dos animais controle. No Campo aberto, notou-se redução
significativa na quantidade de cruzamentos e na exploração vertical nos grupos tratados com
cuprizona quando comparado ao grupo controle, por outro lado animais tratados expostos ao
ambiente enriquecido apresentam índices semelhantes aos dos animais controle. No teste do
labirinto em cruz, com o decorrer do tratamento, o grupo cuprizona aumentou significativamente
sua permanência no braço fechado e diminuiu significativamente sua permanência no braço
aberto. Animais tratados que frequentaram sessões de ambiente enriquecido apresentam
índices semelhantes ao grupo controle e na analise do processo de desmielinização com Luxol
Fast Blue apresentam densidade intermediaria entre os grupos controle após o período de
recuperação. Estes dados sugerem que a exposição ao ambiente enriquecido pode atuar na
recuperação dos animais com desmielinização induzida pela cuprizona, estimulando a
regeneração.
Multiple Sclerosis (MS) is a chronic neurological disease, inflammatory, demyelinating of the Central Nervous System (CNS). To study this disease many models have been used, such as the demyelination induced by cuprizone, induce behavioral changes in experimental animals. Recent studies provide pointed to new clues to the environmental enrichment and their relevance to the aging and neurodegenerative diseases. The environmental enrichment is a condition of housing for animals that allows greater stimulation sensory, motor, social and cognitive in relation to pattern condition, providing the reorganization neuronal circuits. The aim of this study is analyze the demyelination and neurotoxicity process in animals treated with cuprizone exposed to the enriched environment. Lewis rats, males ageing seven weeks, received milled chow and the treated group received addition of cuprizone (0.6 %) in the diet for four weeks. The groups which were permitted to recover received a commercial chow one more week, in a total of five weeks (CEP 103/2010). The animals exposed to the enriched environment were exposed to daily sessions of one hour during the experimental period. In the first, third, and last week of treatment, the animals were subjected to tests of behavior and neurotoxicity. At the end of the treatment, the animals were anesthetized and perfused. Groups treated with cuprizone present scores of neurotoxicity significantly higher than control groups. The results of the Walking Track test demonstrated the hind foot prints impression complete and uniform in the control group. On the other hand, the treated animals presented the uncertain steps. Animals exposed to the enriched environment and were permitted to recover exhibited a uniform pattern, similar to those of control animals. In the open field, a significant reduction in the number of crosses and the readings in the cuprizone treated groups in comparison to the control group. However, treated animals exposed to the enriched environment exhibited indexes similar to control animals. The elevated plus-maze test, the cuprizone group increased significantly its permanence in the closed arm. In addition, treated animals exposed to the enriched environment present indexes similar to the control group. Supporting our clinical findings, histological analysis showed intermediate density between the groups CPZ and CTR EER at the end of the experimental period. These results suggest that the exposition to an enriched environment could act to induce the recovering of the demyelination process induced by cuprizone, activating the regeneration process.
Multiple Sclerosis (MS) is a chronic neurological disease, inflammatory, demyelinating of the Central Nervous System (CNS). To study this disease many models have been used, such as the demyelination induced by cuprizone, induce behavioral changes in experimental animals. Recent studies provide pointed to new clues to the environmental enrichment and their relevance to the aging and neurodegenerative diseases. The environmental enrichment is a condition of housing for animals that allows greater stimulation sensory, motor, social and cognitive in relation to pattern condition, providing the reorganization neuronal circuits. The aim of this study is analyze the demyelination and neurotoxicity process in animals treated with cuprizone exposed to the enriched environment. Lewis rats, males ageing seven weeks, received milled chow and the treated group received addition of cuprizone (0.6 %) in the diet for four weeks. The groups which were permitted to recover received a commercial chow one more week, in a total of five weeks (CEP 103/2010). The animals exposed to the enriched environment were exposed to daily sessions of one hour during the experimental period. In the first, third, and last week of treatment, the animals were subjected to tests of behavior and neurotoxicity. At the end of the treatment, the animals were anesthetized and perfused. Groups treated with cuprizone present scores of neurotoxicity significantly higher than control groups. The results of the Walking Track test demonstrated the hind foot prints impression complete and uniform in the control group. On the other hand, the treated animals presented the uncertain steps. Animals exposed to the enriched environment and were permitted to recover exhibited a uniform pattern, similar to those of control animals. In the open field, a significant reduction in the number of crosses and the readings in the cuprizone treated groups in comparison to the control group. However, treated animals exposed to the enriched environment exhibited indexes similar to control animals. The elevated plus-maze test, the cuprizone group increased significantly its permanence in the closed arm. In addition, treated animals exposed to the enriched environment present indexes similar to the control group. Supporting our clinical findings, histological analysis showed intermediate density between the groups CPZ and CTR EER at the end of the experimental period. These results suggest that the exposition to an enriched environment could act to induce the recovering of the demyelination process induced by cuprizone, activating the regeneration process.
Descrição
Citação
OLIVEIRA, Nathalia Serra de. Avaliação do efeito do ambiente enriquecido sobre o processo de desmielinização e remielinização. 2011. 82 f. Trabalho de conclusão de curso de graduação (Terapia Ocupacional) - Instituto de Saúde e Sociedade, Universidade Federal de São Paulo, Santos, 2011.