Resumo: Conhecer os mecanismos que regem a embriogenese e a maturacao do sistema nervoso e de grande interesse para todos os diferentes ramos da neurociencia. Durante o desenvolvimento dos mamiferos sabe-se que ocorrem fenomenos que levam a definicao do numero de neuronios e refinamento das conexoes sinapticas, que tem caracteristicas proprias nas diferentes regioes do sistema nervoso e podem diferir tambem quanto a sua duracao. Apos o nascimento, diversos sinais neurais e bioquimicos podem modificar significativamente a organizacao morfologica e funcional dos circuitos da medula espinhal, periodo que podemos considerar como critico. Tendo em vista esses fatores, o trabalho visou analisar o proteoma, complemento proteico completo do genoma, da regiao lombar da medula espinhal de rato em busca de proteinas envolvidas com o processo de neurodesenvolvimento. Amostras de medula de rato foram coletadas em diferentes tempos de vida, abrangendo o dia do nascimento (P0), com dois (P2), quatro (P4), sete (P7) e vinte e um (P21) dias de vida e comparadas utilizando-se a eletroforese de duas dimensoes em gel de poliacrilamida e identificacao por espectrometrias de massas. Os perfis proteomicos obtidos permitiram identificar proteinas diferencialmente expressas entre as amostras de P4 e P21. Destas, cinco foram mais expressas em amostras de P4: XLas, fragmento da cadeia beta da ATP sintase trasnportadora de H+, a cadeia 2B da tubulina beta e a neuromodulina; e tres foram mais expressas nas amostras de P21: GFAP, neurofilamento de cadeias polipeptidicas leve e reguladora da proteina G. Estes resultados indicam que ha uma expressao proteica diferencial e que sao as provaveis proteinas envolvidas no processo de desenvolvimento pos-natal da medula espinhal Ver menos

Abstract: To know the mechanisms that govern the embryogenesis and the maturing of the nervous system is of great interest for all the different branches of the neuroscience. During the development of the mammals one is known to take place phenomena that lead to the definition of the number of neurons and refinement of the synaptic connections, which has characteristics own in the different regions of the nervous system and which duration can also differ as for his duration. After the birth, several neurons signs and biochemical can modify significantly the morphological and functional organization of the circuits of the spinal cord, period that we can consider like critic. In mind these factors, the work aimed to analyses the proteome, the genome complete protein complement, of the lumbar region of the spinal cord of rat in search of proteins wrapped with the process of neurodevelopment. Samples of rat's spinal cord were collected in different times of life, including the day of the birth (P0), with two (P2), four (P4), seven (P7) and twenty one (P21) days of life and compared by two dimensional gel electrophoresis and identification by mass spectrometry. The proteomics profiles obtained allowed to identify proteins differently expressed between the samples of P4 and P21. Of this, five were more expressed in samples of P4: XLas, H+ transporting ATP synthase beta chain (fragment), Tubulin beta-2B chain and the neuromodulin; and three were more expressed in the samples of P21: GFAP, Neurofilament light polypeptide and Regulator of G-protein signaling 14. These results indicate that there is a differential protein expression and which are the probable proteins wrapped in the process of native-powders development of the spinal cord Ver menos