Modulaçao do estresse social sobre parâmetros fisiológicos, comportamentais, cognitivos e plasticidade neuronal em saguis (Callithrix jacchus) juvenis: um modelo psiquiátrico e cognitivo

Nos períodos críticos de plasticidade neural ocorre uma maior permissividade do sistema nervoso ao ambiente, por isto, a ação do estresse sobre o individuo e suas repercussões sobre áreas responsáveis pelo controle dos sistemas de resposta ao estresse e por funções cognitivas complexas vem recebendo bastante atenção. A utilização de modelos experimentais translacionais tem sido imprescindível na elucidação destes mecanismos e das patologias associadas. Diante disto, este trabalho investigou os efeitos do estresse social sobre parâmetros fisiológicos, comportamentais, cognitivos e sobre a neurogênese no córtex pré-frontal (CPF) durante um período crítico de plasticidade cerebral, a fase juvenil, em machos de Callithrix jacchus. Durante cinco meses, 5 animais foram acompanhados em suas famílias (GF) e 5 animais foram isolados socialmente por 4 meses (GI), após um mês em observação em ambiente familiar (fase basal- FB). Ao final do 5º mês foram aplicados 2 testes de memória de trabalho (MT) nos animais GF e GI. Em seguida, 3 animais de cada grupo foram sacrificados para análise do fator de neurogênese BDNF ( Brain Derived Neurotrophic Factor) por imunofluorescência no CPF (sub-regiões orbitofrontal e lateral). Os animais do GF não variaram significativamente o cortisol ao longo do estudo, enquanto o GI elevou o cortisol e comportamentos indicadores de ansiedade (CA) na primeira semana do isolamento. Em seguida, o GI apresentou uma redução no cortisol, nos CA, no peso corporal e um aumento de comportamentos estereotipados e da anedonia, alterações tipicamente depressivas em primatas não-humanos. Ao final, o GI apresentaram níveis de cortisol menores que em FB. Ambos os grupos apresentaram dificuldades em realizar e aprender as tarefas cognitivas e a presença de BDNF no córtex pré-frontal foi independente do grupo (GF ou GI), porém correlacionou-se com os níveis de cortisol presentes na ultima semana do estudo, e os animais com presença de BDNF no CPF lateral e orbitofrontal apresentaram maiores níveis de cortisol. Estes resultados contribuem no processo de validação do sagui como um bom modelo psiquiátrico translacional e aponta para possibilidade de estudos sobre transtornos depressivos na juventude e suas repercussões posteriores. Além disto, os resultados observados para as tarefas cognitivas levou-nos a fazer uma releitura dos protocolos utilizados em estudos de memoria de trabalho com animais adultos desta espécie, com a finalidade de aprimora-los facilitando a aprendizagem em animais juvenis, naives e em situações de estresse. Ademais, evidenciou-se pela primeira vez a relação do estresse, cortisol e níveis de BDNF, em animais juvenis desta espécie, com a fim de contribuir com sua utilização como modelo animal neurocognitivo.

Plasticidade dependente da experiência induzida por manipulação da matriz extracelular

The primary somatosensory cortex (S1) receives inputs from peripheral tactile receptors and plays a crucial role on many important behaviors. However, the plastic potential of this region is greatly reduced during adulthood, limiting functional recovery after injuries. This fact is due to the presence, in the brain parenchima, of structures and substances that have an inhibitory effect on plasticity, such as chondroitin sulfate proteoglicans (CSP) present in the perineuronal.nets (PNNs) surrounding a subset of neurons. Maturation of PNNs coincide with the closure of critical periods of plasticity in cortical areas, since CSP act to stabilize synaptic contacts. Removal of CSP is proven to be an effective therapeutic approach to restore plasticity and increase the odds of functional recovery after cortical lesion. In the present work, we removed CSP from the sensorimotor cortex of rats to restore plasticity and promote the compensatory morphofunctional regeneration of cortical circuits modified by removal of mystacial vibrissae during the critical period. Treatment with the CSP-digesting enzyme chondroitinase ABC proved efficient to restore plasticity in S1 circuits, as evidenced by morphological rearrangements and functional recovery.

Plasticidade dependente da experiência induzida por manipulação da matriz extracelular

The primary somatosensory cortex (S1) receives inputs from peripheral tactile receptors and plays a crucial role on many important behaviors. However, the plastic potential of this region is greatly reduced during adulthood, limiting functional recovery after injuries. This fact is due to the presence, in the brain parenchima, of structures and substances that have an inhibitory effect on plasticity, such as chondroitin sulfate proteoglicans (CSP) present in the perineuronal.nets (PNNs) surrounding a subset of neurons. Maturation of PNNs coincide with the closure of critical periods of plasticity in cortical areas, since CSP act to stabilize synaptic contacts. Removal of CSP is proven to be an effective therapeutic approach to restore plasticity and increase the odds of functional recovery after cortical lesion. In the present work, we removed CSP from the sensorimotor cortex of rats to restore plasticity and promote the compensatory morphofunctional regeneration of cortical circuits modified by removal of mystacial vibrissae during the critical period. Treatment with the CSP-digesting enzyme chondroitinase ABC proved efficient to restore plasticity in S1 circuits, as evidenced by morphological rearrangements and functional recovery.

Cooperação e competição entre políticas no Brasil: os cursos da governabilidade no presidencialismo da catalização

Public policies have been studied in the various fields of humanities and social sciences, from different theoretical and technical aspects. However, there is still a lack of studies that incorporate the dimension that encompasses the political action and its interference in such actions, also recognizing the importance of the institutional setting of the Brazilian presidential model in implementing these policies. This fragmented and multiparty system has led to power heterogeneous sets of political parties. Thus, the ministerial offices, more than assisting the President´s government project, manage particularized agendas, which are party biased and have the influence of interest groups in hegemonic themes addressed by government agencies. When these agendas operate in sectoral and specialized policies, the friction level is apparently low. However, when this occurs in intersectoral actions, such as in regional development, there is evidence of strong signs of competition among government agencies, which in theory, should operate in an integrated manner. Although this is not a specific feature of Luiz Inacio Lula da Silva´s government- the period to be studied- there was similar behavior in Fernando Henrique Cardoso´s presidency, one realizes that the expansion of coalition on behalf of governance is increasingly interfering in the outcome of intersectoral public policies, due to these multiple arguments in action. In order to understand these processes, this study focused on the Sustainable and Integrated Development Programme for Differentiated Meso-Regions (PROMESO), part of the National Policy for Regional Development (NPRD). The program provides interface with various government agencies and their public policies in a clear intersectoral design. The research sought to identify and analyze the relationships between government agencies and their programs with interest groups, whether political parties or other segments of civil society, highlighting the logic of favoritism, which poses in second place the integration of actions in the intersectoral policies. Therefore, besides the theoretical debate that incorporates several categories of political science, public administration, public policy, geography and economics, the study focused on secondary sources, using different government agencies databases in order to raise information. It was observed that the interference of partisan politics has been disastrous for some public policies. Thus, the research confirms that cooperative character is fragile within government agencies, often limited to official documents, and that there is indeed, a striking feature of competition, especially when it comes to transversalized policies

Cooperação e competição entre políticas no Brasil: os custos da governabilidade no presidencialismo de coalizão

Public policies have been studied in the various fields of humanities and social sciences, from different theoretical and technical aspects. However, there is still a lack of studies that incorporate the dimension that encompasses the political action and its interference in such actions, also recognizing the importance of the institutional setting of the Brazilian presidential model in implementing these policies. This fragmented and multiparty system has led to power heterogeneous sets of political parties. Thus, the ministerial offices, more than assisting the President´s government project, manage particularized agendas, which are party biased and have the influence of interest groups in hegemonic themes addressed by government agencies. When these agendas operate in sectoral and specialized policies, the friction level is apparently low. However, when this occurs in intersectoral actions, such as in regional development, there is evidence of strong signs of competition among government agencies, which in theory, should operate in an integrated manner. Although this is not a specific feature of Luiz Inacio Lula da Silva´s government- the period to be studied- there was similar behavior in Fernando Henrique Cardoso´s presidency, one realizes that the expansion of coalition on behalf of governance is increasingly interfering in the outcome of intersectoral public policies, due to these multiple arguments in action. In order to understand these processes, this study focused on the Sustainable and Integrated Development Programme for Differentiated Meso-Regions (PROMESO), part of the National Policy for Regional Development (NPRD). The program provides interface with various government agencies and their public policies in a clear intersectoral design. The research sought to identify and analyze the relationships between government agencies and their programs with interest groups, whether political parties or other segments of civil society, highlighting the logic of favoritism, which poses in second place the integration of actions in the intersectoral policies. Therefore, besides the theoretical debate that incorporates several categories of political science, public administration, public policy, geography and economics, the study focused on secondary sources, using different government agencies databases in order to raise information. It was observed that the interference of partisan politics has been disastrous for some public policies. Thus, the research confirms that cooperative character is fragile within government agencies, often limited to official documents, and that there is indeed, a striking feature of competition, especially when it comes to transversalized policies