The entorhinal cortex is reciprocally connected with both neocortical sensory areas and the hippocampal formation, and is thought to play a pivotal role in learning and memory. Changes in synaptic strength are thought to provide the major neurophysiological basis for memory formation, but little is known about synaptic plasticity in the entorhinal cortex. The objectives of this research were to provide a basis for the interpretation of evoked potentials recorded from the entorhinal cortex following pyriform (primary olfactory) cortex stimulation 𝘪𝘯 𝘷𝘪𝘷𝘰, and to determine the conditions under which synaptic enhancements in this pathway may occur and contribute to lasting changes in the processing of olfactory information. The synaptic currents which generate field potentials in the entorhinal cortex following pyriform cortex and medial septal stimulation were first localized to the superficial layers of the entorhinal cortex using current source density analysis techniques in the anesthetized rat. This allowed changes in the strength of these synaptic inputs to be monitored in the awake rat by measuring evoked field potential amplitudes at a single cortical depth. Long-term synaptic potentiation (LTP) in this pathway was reliably induced following stimulation of the pyriform cortex with either epileptogenic stimuli, or with prolonged subconvulsive high-frequency trains. Further, stimulation which results in short-term frequency potentiation effects, was found to increase the amount of LTP induced. Concurrent stimulation of the medial septum at a frequency similar to that of the endogenous theta rhythm also resulted in a cooperative enhancement of the LTP produced. Computational modelling techniques were then used to formalize the heterosynaptic contribution of frequency potentiating medial septal inputs to Hebbian synaptic modification in entorhinal cortex. These results indicate that the frequency of rhythmic activity in sensory afferents and the activity of the medial septum may play critical roles in the regulation of synaptic plasticity in the entorhinal cortex. / Thesis / Doctor of Philosophy (PhD)

Orientador: Krunislave Antonio Nobilo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-26T03:38:50Z (GMT). No. of bitstreams: 1 Oliveira_DeiseLucianePaiva_M.pdf: 3669508 bytes, checksum: 7bfb9a84147c2aa0208a3c91c1d26d0e (MD5) Previous issue date: 2000 / Resumo: Na construção de próteses totais e pistas deslizantes de Nóbilo são utilizados como referência para o plano Dclusal , o ponto anterior, ângulo entre os Incisivos Centrais Superiores e as papilas retromolares. Após mais de 20 anos de experiência clínica com excelentes resultados, esse trabalho objetiva determinar as correlações entre os planos de Camper e o plano oclusal de Nóbilo, entre o plano de Camper e o plano oclusal Natural, entre o plano de Nóbilo e o plano oclusal Natural verificando a validade da técnica utilizada. Selecionamos vinte e cinco pacientes dentados completamente, estando em dimensão vertical f.siológica, sem nunca terem se submetidos a tratamento ortodôntico. Os pacientes foram moldados. Os modelos foram confeccionados e analisados. Na arcada superior, colocou-se um dispositivo de resina acrflica ativada quimicamente com uma esfera de chumbo que guarda a localização do ângulo incisal entre os incisivos centrais superiores. Na arcada inferior também colocou-se um dispositivo com a mesma resina incluindo a esfera de chumbo que guarda a localização do centro, o ponto mais elevado da papila retromolar . Na face foram colocadas as esferas de chumbo sobre o ponto subnasal e tragus. Foram realizadas as teleradiografias, lado esquerdo e direito. Foram feitos os traçados cefalométricos e a análise entre o plano de Camper e o plano oclusal de Nóbilo; entre o plano de Camper e o plano oclusal Natural e entre o plano Nóbilo e o plano oclusal Natural, através de programa de Computação Gráfica Corei Draw. Os resultados obtidos permitiram concluir que a média de angulação encontrada entre o plano oclusal de Nóbilo e o Natural foi de 3,3297 o para o lado esquerdo e de 3,2742° para o lado direito; entre o plano de Camper e Nóbito foi de 5,2960° para o lado esquerdo e de 5,4013° para o lado direito; entre Camper e Natural foi de 1,9630° para o lado esquerdo e de 2,0127° para o lado direito, sendo que estatisticamente não houve diferença significativa entre os lados esquerdo e direito dos respectivos planos. O estudo da relação entre os planos de Camper e plano eclusal Natural nos permitiu a comparação com os valores da literatura que estão em média em torno de 5°, compatível com o tamanho das amostras. Dessa maneira, os valores obtidos nessa pesquisa estão mais próximos do paralelismo. O menor intervalo de confiança encontrado foi em relação ao plano de Nóbilo em relação ao Natural no valor de 0,77210 que determina uma menor variabilidade entre os indivíduos da amostra quando da análise desses planos. Verificou-se pelo teste Exato de Fisher a presença de 2% de plano oclusal reverso na análise entre o plano de Camper e Nóbilo, 4% em relação ao plano de Nóbilo e Natural e 30% em relação ao plano de Camper e Natural. O plano de Nóbilo pode ser adotado com segurança como referência, devido a sua menor variabilidade entre os indíviduos, pela baixa porcentagem de plano oclusal reverso, ou seja, pela sua reprodutibilidade / Abstract: The anterior mark, angle between the superior central incisors, and retromolar pad are used in the construction of total prostheses and NóbHo's gliding plates as reference to the occlusal plane. The aim of this work, after more than 20 years of clinical experience with excellents results, is to determine the correlation between Camper' plane and Nóbilo's occlusal plane, between Camper's plane and the Natural occlusal plane and between Natural occlusal plane and the Nóbilo's occlusal plane. Verifying then the validity of the technique that was used. We selected 25 pacients with complete dentition, in physiological vertical dimension, who had never submitted to an orthodontic treatment. The patients were molded. activated with a sphere of lead that keeps the incisal angle location between the The models were ma de and analysed. A device of Acrylic Resin chemically central superior incisors, was placed at the superior arcade. At the inferior arcade, a device with the same resin was also placed including the sphere of lead that keeps the central location the most elevated point of retromolar pad. On the face, spheres of lead were placed on the subnasal and tragus points. Radiographies were taken of both rtght and left sides. Also, cephatometric tracings and analysis were carried out between Camper's plane and Nóbilo's occfusal plane, between Camper's plane and the Natural ocelusal plane and between the Natural oeelusal plane and Nóbilo's oectusal plane by using Corei Draw, whieh is a graphie eomputer programo The results obtained after the statistical evaluation allowed us to eonelude that the mean angulation found was 3,3297° to left side and 3,2742° to rigth side between Nóbilo's occlusal plane and the Natural one; 5,2960° to left side and 5,4013° to right side between Camper's plane and Nóbilo's one and 1,9630° to left side and 2,0127° to right si de between Camper's plane and the Natural one, and there were no significant difference between lefi and right sides. This last one gave us the opportunity to compare values of the literature whieh are around 50' eompatible with the size of the samples. Thus, the values obtained in this researeh are eloser to parallelism. The lowest index of reliability found was 0,7721° in relaeion to the Natural plane and Nóbilo's one. This value determines a lower variability between the individuais of the sample when these planes are analysed. The presenee of 2% the reverse occlusal plane in the analysis between Camper's plane and Nóbilo's one , 4% in relation to Nóbilo's plane and Natural one, and 30% in relation to Camper's plane and the Natural one was verified by the Exact Test of Fisher. The Nóbilo's oeelusal plane can be accepted with seeurtty due your lower vartability between the individuais, a by lower percentage of the reverse occlusal plane, because your capable of being reproduced. / Mestrado / Fisiologia Oral / Mestre em Odontologia

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La ventilation nasale est vitale pour le nouveau-né, respirateur nasal exclusif. Le tiers antérieur des fosses nasales peut être modifié par une sténose congénitale de l’orifice piriforme, tandis leur partie postérieure peut être fermée par une atrésie choanale uni ou bilatérale ou par des lésions du nasopharynx.Les simulations numériques permettent d’analyser l’écoulement et le conditionnement de l’air en contournant les limites techniques et éthiques rencontrées in vivo. Devant la rareté des données dans la littérature, une étude de faisabilité a été nécessaire et concluante : les modèles numériques sont qualitativement proches de la réalité. Un travail sur les conditions physiologiques chez le nouveau-né a ensuite été réalisé, avec une méthodologie retravaillée. La reconstruction tridimensionnelle des fosses nasales est possible dès la naissance. La création d’une sphère centrée sur la pointe du nez, éloignant le domaine d’entrée de la zone d’intérêt, a permis d’analyser le rôle du tiers antérieur des fosses nasales.La valve nasale joue un rôle majeur en inspiration : perte de charge, accélération, guidage des flux et réchauffement de l’air. Les trois quarts du réchauffement ont lieu en amont du cornet inférieur. Une obstruction nasale entraîne une réduction des vitesses et une augmentation des températures de l'air. La simulation de l’inspiration d’air à 0°C a permis de constater que les fosses nasales permettent d’amortir les effets du refroidissement de l’air extérieur.Ce travail constitue une première approche de la physiologie de la ventilation nasale du nouveau-né par modélisation numérique, indispensable à la compréhension de la pathologie nasale néonatale. / Nasal breathing is essential for the newborn, exclusive nasal breather. The anterior third of the nasal fossae may be modified by a congenital stenosis of the pyriform aperture, while their posterior part may be closed by unilateral or bilateral choanal atresia.Numerical simulations are a good means to analyze airflow and air-conditioning: they circumvent the technical and ethical limits encountered in vivo. Given the rarity of available data in the literature, a feasibility study was necessary and was conclusive: numerical models are qualitatively close to reality. A work on the physiological conditions in newborns was conducted, using refined methodology. The three-dimensional reconstruction of the nasal fossae is possible from birth. The creation of a sphere centered on the tip of the nose, moving the boundary conditions away from the area of interest, made it possible to analyze the role of the anterior third od the nasal fossae.The nasal valve plays a major in inspiration: it is a zone of pressure loss, acceleration, flow guidance and air warming. Three-fourths of the warming takes place upstream the inferior turbinate. A partial nasal obstruction modifies these results with lower velocities and higher temperature of the air. The simulation of the inspiration of cold air (0°C) has shown that the nasal fossae can dampen, without canceling, the effects of air cooling. This work is a first approach to the physiology of nasal ventilation of the newborn by numerical modeling, which is essential to the understanding of neonatal nasal pathology.