Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-09T00:26:04Z No. of bitstreams: 1 StefanoPupeJohann_TESE.pdf: 36592987 bytes, checksum: f44357f3110776cf9f7cb628b2d65a95 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-09T00:36:11Z (GMT) No. of bitstreams: 1 StefanoPupeJohann_TESE.pdf: 36592987 bytes, checksum: f44357f3110776cf9f7cb628b2d65a95 (MD5) / Made available in DSpace on 2016-04-09T00:36:12Z (GMT). No. of bitstreams: 1 StefanoPupeJohann_TESE.pdf: 36592987 bytes, checksum: f44357f3110776cf9f7cb628b2d65a95 (MD5) Previous issue date: 2015-03-20 / Os neurocientistas tem uma diversidade de perspectivas com as quais podem classificar diferentes partes do c?rebro. Com o surgimento de t?cnicas baseadas na gen?tica, como a optogen?tica, se torna cada vez mais importante identificar se um grupo de c?lulas, definidas atrav?s de morfologia, fun??o ou posi??o anat?mica possui um padr?o caracter?stico de express?o de um ou mais promotores gen?ticos. Isso permitiria melhores formas de estudar essas popula??es de neur?nios definidas geneticamente. Neste trabalho, eu apresento uma discuss?o te?rica e tr?s estudos experimentais nos quais essa foi a principal quest?o sendo abordada. O Estudo I discute as quest?es envolvidas em selecionar um promotor para estudar estruturas e subpopula??es na ?rea Tegmental Ventral. O Estudo II caracteriza uma subpopula??o de c?lulas na ?rea Tegmental Ventral que compartilha a express?o de um promotor, que ? anatomicamente muito restrita, e que induz avers?o quando estimulada. O Estudo II utiliza uma estrat?gia similar para investigar a subpopula??o no n?cleo subtal?mico que expressa PITX2 e VGLUT2 que, quando inativada, causa hiperlocomo??o. O Estudo IV explora o fato de que um grupo de c?lulas previamente identificadas no Hipocampo Ventral expressa CHRNA2, e indica que essa subpopula??o pode ser necess?ria e suficiente para o estabelecimento do ritmo teta (2-8 Hz) no Hipocampo Ventral de camundongos anestesiados. Todos esses estudos foram guiados pela mesma estrat?gia de identificar um promotor gen?tico capaz de permitir o controle de uma popula??o de neur?nios identificada geneticamente, e eles demonstram as diferentes formas em que essa abordagem pode generar novas descobertas. / Neuroscientists have a variety of perspectives with which to classify different parts of the brain. With the rise of genetic-based techniques such as optogenetics, it is increasingly important to identify whether a group of cells, defined by morphology, function or anatomical location possesses a distinct pattern of expression of one or more genetic promoters. This would allow for better ways to study of these genetically defined subpopulations of neurons. In this work, I present a theoretical discussion and threeexperimental studies in which this was the main question being addressed. Paper I discusses the issues involved in selecting a promoter to study structures and subpopulations in the Ventral Tegmental Area. Paper II characterizes a subpopulation of cells in the Ventral Tegmental Area that shares the expression of a promoter and is anatomically very restricted, and induces aversion when stimulated. Paper III utilizes a similar strategy to investigate a subpopulation in the subthalamic nucleus that expresses PITX2 and VGLUT2 which, when inactivated, causes hyperlocomotion. Paper IV exploits the fact that a previously identified group of cells in the ventral hippocampus expresses CHRNA2, and indicates that this population may be necessary and sufficient for the establishment of the theta rhythm (2-8 Hz) in the Local Field Potential of anesthetized mice. All of these studies were guided by the same strategy of characterizing and studying the role of a genetically defined subpopulation of cells, and they demonstrate the different ways in which this approach can generate new discoveries.