On the use of transgenic mice and optogenetics to characterize genetically defined subpopulations of neurons

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.

Os programas de incentivo à cultura e o processo de fomento às organizações culturais no rio grande do norte: o caso da Casa da Ribeira em Natal

Since the emergence of the first demands for actions that were intended to give greater attention to culture in Brazil, came the first discussions which concerned the way the Brazilian government could have a positive influence in encouraging the culture, as is its interaction with the actors interested and involved with the cause. During the military dictatorship, there were programs which relied on the direct participation of the State to ensure that right, from the viewpoint of its support and implementation of public resources in developing the "cultural product" to be brought to society in its various forms of expression - all this, funded by the government. It is an example of "EMBRAFILMES" and "Projeto Seis e Meia", continued until the present day in some regions of the country, though maintained by entities not directly connected with the administration or the government. However, it was from the period of democratization and the end of the dictatorship that the Brazilian government began to look at the different culture, under its guarantee to the society. Came the first incentive laws, led by "Lei Sarney" Nº 7.505/86, which was culture as a segment which could receive foreign assistance in order to assist the government in fulfilling its public duty. After Collor era and the end of the embargo through the encouragement of culture incentive laws, consolidated the incentive model proposed in advance of Culture "Lei Sarney" and the federal laws, state and local regimentares as close to this action. This applies to the Rouanet Law (Lei Rouanet), Câmara Cascudo Law (Lei Câmara Cascudo) and Djalma Maranhão Cultural Incentive Law (Lei de Incentivo à Cultura Djalma Maranhão), existing in Natal and Rio Grande do Norte. Since then, business entities could help groups and cultural organizations to keep their work from the political sponsorship under control and regiment through the Brazilian state in the form of their Cultural Incentive Law. This framework has contributed to the strengthening of NGOs and with the consolidation of these institutions as the linchpin of Republican guaranteeing the right to access to culture, but corporate social responsibility was the one who took off in the segment treated here, through the actions of Responsibility Cultural enterprises arising from the Cultural Organizations. Therefore, in the face of this discourse, this study ascertains the process of encouraging the Culture in Rio Grande do Norte from the Deviant Case Analysis at the Casa da Ribeira, the main Cultural Organization that operates, focused action in Natal in order to assess the relationships established between the same entity and the institutions which are entitled to maintain the process of encouraging treated in this study - Enterprise, from the viewpoint of corporate sponsorship and Cultural Responsibility and State in the form of the Laws Incentive Funds and Public Culture Incentive

Os forrós da Serra da Gameleira (São Tomé/RN) : etnicidade, festa e sociabilidade

This work intends to describe and analyze the parties of forró that happen in Serra da Gameleira, in São Tomé/RN. Serra is a divided social space: groups of different ethnic origins live together in Gameleira de Baixo, Salgadinho (or Gameleira de Cima) and Chaves Belas. They are approximately two hundred families that live exclusively from agriculture. We try to understand how the parties inform about the social organization, the ethnic composition of the families that live there and the past of Serra, through the genealogy offorró players. In the discussion, we identify the festive places: in the total, we have Five houses of forró that function regularly one of them has been described. The private and public spaces inside them are intimate related, with no clear limits between the house of forró and the residence. Each house of forró has an owner, that regularly makes the parties, mobilizing a big part of the inhabitants, and provoking the straitening of the social relations. Observing the festive sociability between different social segments, the forró appears like na element that minimizes social conflicts, providing news ways of association and cooperation in the space of Serra da Gameleira. For the collection of facts, we used the ethnographic method, through the direct observation, interviewing and documentary research. The local history is recounted following the routes of oral memory and historical documents analysis. In the end of the analysis, we concluded that music and party are elements that aggregate the different groups that live in the location and determine forms of expression of what is seen as a traditional culture

Papel da proteína de reparo XPC na regulação das proteínas de reparo APE1, OGG1 e PARP-1 em células humanas e de camundongos

studies using UV as a source of DNA damage. However, even though unrepaired UV-induced DNA damages are related to mutagenesis, cell death and tumorigenesis, they do not explain phenotypes such as neurodegeneration and internal tumors observed in patients with syndromes like Xeroderma Pigmentosum (XP) and Cockayne Syndrome (CS) that are associated with NER deficiency. Recent evidences point to a role of NER in the repair of 8-oxodG, a typical substrate of Base Excision Repair (BER). Since deficiencies in BER result in genomic instability, neurodegenerative diseases and cancer, it was investigated in this research the impact of XPC deficiency on BER functions in human cells. It was analyzed both the expression and the cellular localization of APE1, OGG1 e PARP-1, the mainly BER enzymes, in different NER-deficient human fibroblasts. The endogenous levels of these enzymes are reduced in XPC deficient cells. Surprisingly, XP-C fibroblasts were more resistant to oxidative agents than the other NER deficient fibroblasts, despite presenting the highest of 8-oxodG. Furthermore, subtle changes in the nuclear and mitochondrial localization of APE1 were detected in XP-C fibroblasts. To confirm the impact of XPC deficiency in the regulation of APE1 and OGG1 expression and activity, we constructed a XPC-complemented cell line. Although the XPC complementation was only partial, we found that XPC-complemented cells presented increased levels of OGG1 than XPC-deficient cells. The extracts from XPC-complemented cells also presented an elevated OGG1 enzimatic activity. However, it was not observed changes in APE1 expression and activity in the XPCcomplemented cells. In addition, we found that full-length APE1 (37 kDa) and OGG1- α are in the mitochondria of XPC-deficient fibroblasts and XPC-complemented fibroblasts before and after induction of oxidative stress. On the other hand, the expression of APE1 and PARP-1 are not altered in brain and liver of XPC knockout mice. However, XPC deficiency changed the APE1 localization in hypoccampus and hypothalamus. We also observed a physical interaction between XPC and APE1 proteins in human cells. In conclusion, the data suggest that XPC protein has a role in the regulation of OGG1 expression and activity in human cells and is involved mainly in the regulation of APE1 localization in mice. Aditionally, the response of NER deficient cells under oxidative stress may not be only associated to the NER deficiency per se, but it may include the new functions of NER enzymes in regulation of expression and cell localization of BER proteins

A reestruturação produtiva e as novas formas de organização do trabalho: a experiência do transporte alternativo no município de Belém/PA

The study made in this thesis analyzes the new form of work organization at the urban collective transportation sector, so called Altemative Transportation which is a new form of public transportation that appears in the Brazilian urban context by the mid ninety' s, this work is made by independent or sub-contracted workers, usually organized in cooperatives . It reflects the investigation of new forms of precarious work, unformal which has been expanding in the urban transportation sector. Thus, discusses non regulation of the services sector problem the ways of survival of exc1uded workers from the formal work market mainly afier the capital productive restructure. It has as privileged area of investigation, the sector policy of urban transportation that make field of the main nets of political articulations that define the dynamic of the urban space. It is known that the urban collective transportation allows the access to the production, circulation and general consumption being necessary to the mobility of the resident population, mainly to those with low purchasing capacity. It becomes a field of empirical investigation at the Belem municipal, located at the Amazonic region - north Brazil. The main points dealed on this research start from concrete relations from the daily life of workers that deve1op their activity on the altemative transport mediated with theoretical references needed for understanding and interpretation of the studied reality. The investigation strategies were built from the abstract (theorical knowledge produced for the reality analyze) in concrete by the investigation quantitative-qualitative from this area of urban policy, making up possible the formation of a references chart to the analyses of the studied subject. Rescue his historicity, from characterization of the urban space of the metropolitan region of Belem passing true the forms of organization and urban services performances while essential production and reproduction element of the social relations. Identifies the main individuals that historically have been participating in the construction of the municipality transport policy and the ways of expression of the local political strength relations. Outstand the State paper on the net of established relations near the local power, as well as outstand the importance of social sciences in the understanding of urban policies in the transportation area, trying to bring input to the academicals -scientific debate .The above e1ected and mentioned points in this study are crucial for a critical reflection of the transportation policies. That relation is not given, but historically built at the power relation chart that makes up this unique area of the urban policies

Identidade e participação da comunidade rural nos processos de desenvolvimento local:desafios e competências do regulado de Nhambita-Moçambique

This thesis is defined as a reflection on the mechanisms of expression and insertion of the homo situs in the participatory governance in Mozambique. For a better understanding of this social fact, it was settled a periodization which covered the decline of colonialism at the time of the independence, which was proclaimed in June 1975, the civil war that lasted over 16 years and the period of the democratic State, further established. Therefore, we sought to understand the mechanisms and failures of the participation of the homo situs in local development projects that absorbed the needs and problems of these peasants, not mobilizing the skills and social competences of these communities. It would be essential for the homo situs a genuine democratic practice involving a political culture based on the social construction of the territories of the traditional man which was characterized by being procedural and historical, finding in participation its higher base. In this context, it would be desirable that the community development in Mozambique could contemplate and respect the choices of the homo situs. For this purpose, it would be fundamental the consistency between theory and practice, which builds and rebuilds, continually the competence of the peasants, facilitating the possibility of realization of their primordial aspirations. In the research, it became apparent that there is not a continuous process of participation of the rural communities, which appear as participants, only at the time of the implementation of the activities. Therefore, even having the participation of the communities expected by the law, with predictable moments of discussion and necessary conditions for that, the State failed to establish an ongoing process of democratic dialogue with traditional populations, as well as it failed to organize, properly, accurate informational bases to help solve the problems of rural areas. These facts have led to obstacles to the process of conquest of the human and civil rights of the traditional communities

A investigação criminal e a vedação ao anonimato no sistema jurídico brasileiro

The thesis, prepared with basis on deductive reasoning (through the utilization of general concepts of the fundamental rights theory) and on inductive logic (by means of the consideration of particular situations in which the theme has been approached) deals with the criminal investigation and the prohibition of anonymity in the Brazilian law system. The state criminal investigation activity presents not only a substantial constitutional basis, due to the objective dimension of fundamental rights (which imposes an obligation to protect these essential values), but also a formal constitutional basis, arising from the administrative principles of rule of law, morality and efficiency, referred to in article 37 of the Constitution. The criminal investigation, however, is not an unlimited pursuit, being restrained by the duty to consider fundamental rights that oppose to its realization. One of the limits of the state investigation activity, in the Brazilian law system, is the prohibition of anonymity, referred to in article 5°, IV, of the Constitution. This prohibition is a direct constitutional restriction to the freedom of expression that aims to ensure the credibility of the diffusion of ideas and prevent the abusive exercise of this fundamental right, which could harm both persons and the state, with no possibility of punishment to the offending party. Generally, based on this prohibition, it is affirmed that a criminal investigation cannot begin and progress founded on anonymous communication of crimes. Informations about crimes to the investigative authorities require the correct identification of the stakeholders. Therefore, it is sustained that the prohibition of anonymity also comprehends the prohibition of utilization of pseudonyms and heteronyms. The main purpose of this essay is to recognize the limits and possibilities in starting and conducting criminal investigations based on communication of crimes made by unidentified persons, behind the veil of anonymity or hidden by pseudonyms or heteronyms. Although the prohibition of article 5°, IV, of the Constitution is not submitted to direct or indirect constitutional restrictions, this impediment can be object of mitigation in certain cases, in attention to the constitutional values that support state investigation. The pertinence analysis of the restrictions to the constitutional anonymity prohibition must consider the proportionality, integrated by the partial elements of adequacy, necessity and strict sense proportionality. The criminal investigation is a means to achieve a purpose, the protection of fundamental rights, because the disclosure of facts, through the investigatory activity, gives rise to the accomplishment of measures in order to prevent or punish the violations eventually verified. So, the start and the development of the state criminal investigation activity, based on a crime communication carried out by an unidentified person, will depend on the demonstration that the setting up and continuity of an investigation procedure, in each case, are an adequate, necessary and (in a strict sense) proportional means to the protection of fundamental rights

Liberdade de expressão artística: concepções filosóficas, fundamentalidade constitucional e política da pluralidade

The right to artistic expression, freedom granted in the western democratic constitutionalism, is a fundamental right that cyclically, compared to other cohesive rights of expression, has been forgotten and put in an irrelevant juridical-dogmatic position. The first reason for this behaviour that disesteems artistic freedom is the valorisation of rationalism and scientificism in the modern society, subordinating academic researches to utilitarianism, relegating the purpose of feelings and spirituality on men s elocution, therefore, we investigate, guided by philosophy, the attribution of art on human formation, due to its capacity in harmonising reason and emotion. After that, we affirm the fundamental right to artistic expression s autonomy in the 1988 valid constitutional order, after a comparative explanation of freedom in the Fundamental Laws of United States, Portugal, Spain and Germany; and the construction historic-constitutional of the same right in the Brazilian Constitutions. In this desiderate, the theoric mark chosen is the Liberal Theory of the fundamental rights, guiding the exam through jusfundamental dimensions: juridical-subjective and juridical-objective. Whilst the first, classical function of resistance, delimitates the protection area of the artistic expression right from its specific content, titularity and its constitutional and subconstitutional limits, the other one establishes it as cultural good of the Social Order, defining to the State its rendering duties of protection, formation and cultural promotion. We do not admit artistic communication, granted without legal reserve, to be transposed of restrictions that belong to other fundamental rights and, when its exercise collides with another fundamental right or juridical-constitutional good, the justification to a possible state intervention that tangentiates its protection area goes, necessarily, through the perquisition of the artist s animus, the used method, the many viable interpretations and, at last, the correct application of the proportionality criteria. The cultural public politics analysis, nevertheless, observes the pluralism principle of democratic substratum, developer of the cultural dialogue and opposed to patterns determined by the mass cultural industry. All powers are attached, on the scope of its typical attributions, to materialise public politics that have the cultural artistic good as its aim, due to the constant rule contained in §1, art. 5º of the Federal Constitution. However, the access and the incentive laws to culture must be constantly supervised by the constitutional parameter of fundamental right to equality

Livre expressão :para que te quero? o interesse público no ensino do Jornalismo

The main objective of this research was studying the meanings of the freedom of expression and what professors of Journalism think about the way those meanings are used in pedagogical practices. The term freedom of expression is commonly used in journalism even though it is not so studied, consequently we don t have a word to define it. Therefore, we related the term freedom of expression in Journalism teaching to the condition as the object of this study, aiming to establish a connection among the term, the right, free expression and the endurance of the right. The theorical support to understand the dynamic of the meanings of the freedom of expression in the social practice of Journalism teaching was based in the Hegeliana dialetic theorical principles and in the language philosophy more specifically in Bakhtin s perspective from which we can mention the social auditorium, immediate conditions of production and a wider social horizon as the main categories of analysis. This study is a qualitative research with an interacionist perspective anchored in a semi-structured interview as a privileged method of data collecting made with ten professors from Journalism graduation. The analysis reveals that, in the interviewers perspective, there would be a deceiving practice from freedom of expression in the journalism teaching in which emerges either in speeches with handbills spreading the fear and/or under a stimulus form to concealment

Nas asas de Ícaro: uma análise da Pedagogia Freinet do 2º ao 5º ano do Ensino Fundamental na perspectiva da ação docente continuada

Célestin Freinet was one of the most memorable educators of the twentieth century. He presented some educational alternatives that had the objective of stimulating the construction of pedagogic actions to promote the social development of the student based upon a work centered on the free expression as the way to self-structure the knowledge. With a permanent proposal of research based on the enquiry-based learning, Freinet set human capacity (cognitive, social-affective, psychometrical) taking cooperation in consideration on the processes of knowledge construction. Based on this referential, this present work has the objective to show Freinet s pedagogy in a continuous teaching action from 2nd to 5th grade focusing the teacher s discourse and also the educative practice of the students of a city public school in Natal. The observed work revealed the teacher s discourse and educative experience and delineated the students development while immersed into Freinet s educational practice. By virtue of the nature and specificity of the theme that guided our research, we chose a qualitative approach to it, as a way of conducting ourselves during our investigative process. We observed and analyzed the method that was used to conduct the activities in the classroom, as well as the ways of expression that the children used through drawings, words (oral text), or through writing. We highlight, among the written texts, the individual and collective texts, and also letters and notes, which during some moments served as a base to express a diversity of languages. The results, after a analyzing the research data, point towards a teaching practice that favors the construction of a significant learning process through the grasping of the school environment, on which all these factors are based: society, knowledge acquisition, abilities, attitudes and values. This learning process also strengthens human solidarity bonds and mutual tolerance, on which the student s social life is seated.

A videobiografia como dispositivo de pesquisa-ação-formação: uma prática educativa com adolescentes abrigados

The focus of this thesis is a production of video biographies with/by sheltered teenagers. The general objective is discuss the potential production of video biographies while a device of research-action-formation. From de point of view of research, the study interrogates cultural practices that demarcates the passage of teenagers in shelter institutional; From the point of view of action, seeks to identify the modes of appropriation of space for audiovisual creation by teenagers; and, from the point of view of formation, asks the potentiality of audiovisual language while the way from which teenagers can auto-configure themselves responsibly, in the reinvention of places and others worlds for them. The research falls in the intersection of qualitative approach of ethnographic and of research-action-formation. Is anchored theoretically in autobiographical approaches - Pineau (2005); Passeggi (2008); Delory-Momberger (2008); Josso (2010) e Bertaux (2010) - and in the filmic method - Ramos (2003); Wohlgemuth (2005) and Comoli (2009). Participated in the research eleven teenagers members of the production cycle of biographical traces, among these, the three teenagers who advanced to cycles of audiovisual recording life narratives and reflective exercises around produced reports, procedures of which we extract the set of empirical material analyzed The analysis revealed that teens use in under three types of practices: the practices of mess , as way of expression; the practices of evasion , as resistance to restraint the right to come and go, and the practices of claim a regime of "truth" to the institutional environment, which emerge as a survival tactic in the face of paths desvínculos, family abandonment and neglect. The study also showed the appropriation of spaces of audio-visual creation meaningful expression through music by teenagers and encourage dialogue between and with the teenagers and the achievement of reflective exercises focused for awareness of their stories in becoming. These findings show a broader sense the thesis that visual language is a potent mobilizer artifact reflections and empowerment of individuals in situations of social exclusion

Corpo e aprendizagem em Boris Cyrulnik e em Merleau-Ponty

This research seeks to identify views of the body and learning the authors Boris Cyrulnik and Merleau - Ponty, thus tracing reflective for the educational field in several areas, with emphasis on physical education paths . We notice that the above authors present a wide collection of books, needing to develop this theoretical construct a limitation in their works. Therefore , on the theme of the body , were used mainly books The Sixth Sense , Boris Cyrulnik and Phenomenology of Perception , Merleau- Ponty , as both present in their organizational context a specific chapter on this subject . The phenomenological approach is included as path to be taken to devise this study because it is based on daily reflections that the human being perceives through his experiences with his peers and mainstream culture. The phenomenological reduction was carried out from the readings and interpretations of texts, writers and commentators, as well as approaching with life aspects of experience as a police officer and professor of ethics. The interpretation points to the understanding of body and learning that can be propagated within the Physical Education and as a way to understand and learn the constructs lived through sensitivity. The design of the body, feelings and affections of Boris Cyrulnik firm the empathetic bonds between human beings, bringing confidence to explore the world, learning through the new link with the other. This notion is close to the notion of expressive body Merleau Ponty, who holds intentions in their gestures (movements), entwining in time and space. Boris Cyrulnik and Merleau-Ponty expressed as the human being is enigmatic, lying embedded in a social and cultural world, so the experiences to traçarem existential trajetória and learning need in order to enaltercer freedom of expression as a mechanism that can be deployed in the appropriation of concepts and the criticality of the subject facing widespread theories (biological, social, anthropological , etc.) . From the reflections of the research is that recomneda Physical Education , as epistemological working area apprenticeships stemmed body movements should enable reflection on their practice, other do be done, but enabling the creation of different senses and meanings each body attitude

Avaliação de dois clones de Escherichia coli recombinante quanto ao crescimento e expressão de antígenos de Leishmania chagasi (kmp11 e P36)

Visceral leishmaniosis caused by Leishmania chagasi, also known as calazar, presented, in the period from 1990 to 2005, tax of incidence in Brazil varying between 1 and 3 cases for 100 000 inhabitants. The Northeast region that up to the year of 2000 contributed with almost 90% of the registered cases is reducing his participation in the current decade, reaching 56% in 2005. Conventional leishmaniasis treatment is costly and it shows high toxicity, demanding more research for alternative treatments, with special interest in development of vaccines and diagnosis kits which include production of recombinant antigens by host cells. Escherichia coli has been the microorganism most studied and used as a host for recombinant protein production. Therefore, the aim of this work was to study the influence of induction on cellular growth and to verify the type of Leishmania chagasi antigens expression (intra or extracellular) during two recombinant E. coli clones (kmp11 and P36) cultivation in rotary incubator (shaker) using three different media (2xTY, TB, FASS+EL). For that, tests were carried out using conditions established in the literature for E. coli (37°C and 200 rpm) and media supplemented with antibiotics to guarantee that only competent cells grows. First, tests were carried out without induction in order to verify the two microorganisms kinetic behavior (growth and substrate consumption) in different media. Next, the induction was carried out through the addition of IPTG (1mM as final concentration), at the first hour of cultivation. It was observed that protein expression were intracellular for all clones and media tested, however the highest level of expression was clearly observed by the electrophoresis band density (intensity) for 2xTY medium and kmp11 protein. Although it contains the lowest substrate concentration, consequently, a reduced cellular concentration when compared to other media, it appeared that this medium and clone combination is the most indicated for recombinant protein production. Therefore, the objective of this work was achieved, since the interested proteins were produced. Consequently, this result motivates new studies for production optimization using different cultivation strategies

Palavras da maldição: O Ceará de José Alcides Pinto entre símbolos e alegorias.

This work treats about the speeches that produced the crisis of symbols of Ceará, researching on matters and ways of expression of space between 1950s and 1970s. Therefore, we search discursive practices that since the end of nineteenth century built the identity of Ceará and in the middle of twentieth century produced the crisis of modes of seeing and telling the space in front of enunciations of the national modernization, especially with the emergence of politics by SUDENE to the Northeast, the progressive actions by Catholic Church, the defense of tradition by regional literature of union of Ceará Clã. The contradictions between the glorification and fear the modernization of Brazil produced on the space speeches that his identity would be fractured, that the old symbols of drought, cangaço, mysticism and colonels declined. Among analyzed speeches, we centered the analysis of Trilogia da Maldição formed of novels O Dragão, of 1964, Os Verdes Abutres da Colina and João Pinto de Maria: a biografia de um louco by José Alcides Pinto. In this novel, the enunciation of the crisis of symbologies about the space produced another aesthetic, the allegory, which, mixed with the mystical and melancholy, in search of ways to restore the language of the old themes Ceará, drop of Ceará the same stigma of anti-modern space, where the images of delay changed icons of a fractured identity in front of the modern streams, where the word was transformed in the dimension precarious and redeemer of the tradition, of old, of nature, of the plenitude of senses. In Jose Alcides, the colonel returns as the origin of the lost space, the drought is the revolt of God against the devil place, the apocalypse, the end imminent threat to the village, signs that fantastic, however, are in dialogue with the settings space and time in which they were produced

Imunoexpressão das claudinas -1 e -7 em ameloblastomas e germes dentais humanos

We investigated the immunohistochemistry expression of claudins -1 and -7 in ameloblastoma and in human dental germs on the pattern of distribution (focal, regional or diffuse), the cells that expressed (if central or peripheral) and the location of that expression in the cell components recital membrane, cytoplasm and nucleus. Among the 29 cases of ameloblastoma, 24 were type solid and 6 unicystic. In 7 mandibular specimens of human fetuses found dental germs from the stage of bud to the crown. We note that the pattern of expression in the dental germs was variable for claudinas studied according to the cell type and stage of differentiation and was invariate only in the cells of stellate reticulum. In epithelium internal of enamel organ, claudin-1 has been decreasing with the progression of differentiation as to claudina-7 that was found in the cells of the peripheral papilla. For ameloblastoma the expression was more significant than that observed in dental germs. Fisher s exact test no found association between the expression of claudinas cells in central and peripheral and the type of ameloblastoma (solid or unicystic). Thus, in general the claudin-1 was positive in the central cell of 93,1% of the cases and in peripheral cells of 51,7%. The claudin-7 was expressed in the cells of all cases central and peripheral cells from 89,7%. For both claudins the distribution was predominantly diffuse cells both in central and peripheral cells. Given our findings it is suggested that the expression of claudins may be indicative of the involvement of these molecules in morphogenetics events culminating with the dental development and that possibly influence the development of neoplastic ameloblastoma