Made available in DSpace on 2014-12-17T15:37:06Z (GMT). No. of bitstreams: 1 JoseRLPC_DISSERT.pdf: 5508734 bytes, checksum: 81d9b9240f44158090493b3b76b26129 (MD5) Previous issue date: 2011-10-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The 3-hydroxytyramine/dopamine (DA) is a monoamine of catecholamineric group and consists in the progenitor substantia of synthesis of noradrenaline and adrenaline, having the enzyme tyrosine hydroxylase as a regulator of this process. Nuclei of midbrain expressing DA are the retrorubral field (RRF, A8 group), the substantia nigra pars compacta (SNc, A9 group) and the ventral tegmental area (VTA, A10 group). These nuclei are involved in three complex circuitry called mesostriatal, mesocortical and mesolimbic, which are related directly with various behavioral manifestations such as motor control, reward signaling in behavioural learning, motivation and pathological manifestations of Parkinson s disease and schizophrenia. The aim of this study was describe the morphology of midbrain dopaminergic neurons (A8, A9 and A10) of the rock cavy (Kerodon rupestris), a rodent belonging to the family Caviidae typical of the Brazilian Northeast, which is being adopted as a model for neuroanatomical studies in laboratory of neuroanatomy of the Federal University of Rio Grande do Norte. Coronal sections of brains of the rock cavies were submitted to staining by Nissl s method and immunohistochemistry against tyrosine hydroxylase. The nuclear organization of the midbrain dopaminergic nuclei of the rock cavy is very similar to that found in other animals of the order Rodentia, except by the presence of the tail of substantia nigra, which was found only in the studied species. We concluded that the midbrain dopaminergic nuclei are phylogenetically stable among species, but we think to be it necessary to expand the studies about the particularity found the rock cavy, investigating its occurrence in other species of rodents or investigating its functional relevance / A 3-hidroxitiramina/dopamina (DA) ? uma monoamina do grupo das catecolaminas e consiste na subst?ncia precursora da s?ntese de noradrenalina e adrenalina, tendo a enzima tirosinahidroxilase (TH) como reguladora deste processo. Os n?cleos do mesenc?falo que expressam DA s?o a zona retrorubral (RRF, grupo A8), a subst?ncia negra pars compacta (SNc, grupo A9) e a ?rea tegmental ventral (VTA, grupo A10). Tais n?cleos est?o envolvidos em tr?s complexas circuitarias, chamadas mesostriatal, mesol?mbica e mesocortical, as quais est?o relacionadas diretamente com diversas manifesta??es comportamentais como controle da motricidade, sinaliza??o de recompensa na aprendizagem comportamental, motiva??o e nas manifesta??es patol?gicas da Doen?a de Parkinson e esquizofrenia. O objetivo deste estudo foi descrever a morfologia dos n?cleos dopamin?rgicos do mesenc?falo (A8, A9 e A10) do moc? (Kerodon rupestris), um roedor pertencente ? fam?lia Caviidae t?pico da regi?o Nordeste do Brasil, que est? sendo adotado como modelo para estudos neuroanat?micos no Laborat?rio de Neuroanatomia da Universidade Federal do Rio Grande do Norte. Sec??es coronais do enc?falo do moc? foram submetidas ? colora??o pelo m?todo de Nissl e imunoistoqu?mica contra tirosina-hidroxilase. A organiza??o nuclear do sistema dopamin?rgico do mesenc?falo do moc? ? muito semelhante ao que foi encontrado em outros animais da ordem Rodentia, exceto na presen?a da cauda da subst?ncia negra, que foi encontrada apenas na esp?cie em quest?o. Conclu?mos que os n?cleos dopamin?rgicos do mesenc?falo s?o filogeneticamente est?veis entre as esp?cies, por?m percebemos a necessidade de se ampliar os estudos acerca da particularidade encontrada no moc?, seja investigando a sua ocorr?ncia em outras esp?cies de roedores, seja investigando a sua relev?ncia funcional