Exposure to abnormal motion produces a variety of behavioural effects in both human and non-human species. The general purpose of the present studies was to produce and investigate some of these effects in the laboratory rat. In the first series of experiments, rats displayed appreciable decreases in reactivity to noxious stimuli presented after exposure to brief periods of different types of motion. This motion-induced antinociception was found to persist for periods of up to 15 min. A second series of experiments examined the role of the vestibular system in this motion-induced antinociception phenomenon. Rats whose peripheral vestibular apparatus had been rendered insensitive to accelerative stimuli did not exhibit motion-induced antinociception. Subsequent experiments attempted to delineate the role of some individual components of the central vestibular system but no single component investigated was found to play a major role in the production of antinociception. Experiments in this and the preceding series of experiments also demonstrated that the antinociceptive effect could be dissociated from dizziness or acute vestibular dysfunction. In the third series of experiments, the physiological mechanisms by which vestibular stimulation produces antinociception were investigated. Experiments in this series demonstrated that motion-induced antinociception could be blocked by opiate antagonists and that the motion-induced antinociceptive effect showed cross-tolerance with chronic morphine administration. These two findings strongly implicate an endogenous opiate peptide (endorphin) system as the underlying mechanism for mot ion-induced antinociception. The brief duration of the antinociceptive effect and the fact that disruption of the pituitary-adrenal axis did not affect motion-induced antinociception suggested that the opiate peptides involved were the enkephalins rather than B-endorphin. Other behavioural effects of abnormal motion were reported in the the fourth series of experiments. The resemblance between the symptoms of motion sickness and those of opiate administration suggested that endogenous opiate peptides may mediate motion sickness. Although exposure to abnormal motion did produce a substantial conditioned taste aversion (a behavioural assay for motion sickness in the rat), attempts to attenuate the aversion with two different opiate antagonists were unsuccessful. These results suggested that abnormal motion exerts its illness-producing effects through some mechanism other than an endogenous opiate system. In the final experiment, rats that were exposed to a brief period of abnormal motion subsequently exhibited a suppression of defensive burying behaviour that was similar to that produced by anxiolytic drugs. The results of this study indicate that abnormal vestibular stimulation may have a variety of different behavioural effects in rats. However, it appears that no single mechanism can account for all of these effects. / Arts, Faculty of / Psychology, Department of / Graduate

Objetivos: analisar a associação entre otite média crônica não colesteatomatosa (OMCNC) e os resultados obtidos no video head impulse test (vHIT). Delineamento: tipo transversal. Métodos: a amostra foi selecionada em ambulatório especializado de um hospital universitário. A inclusão dos pacientes neste estudo obedeceu aos seguintes critérios: idade entre 7 e 59 anos; diagnóstico de OMCNC unilateral, com orelha contralateral normal; não ter realizado cirurgia otológica prévia; não ter comprometimentos cognitivos e/ou neurológicos e/ou motores registrados nos prontuários. Os critérios de exclusão foram: impossibilidade de retirada de maquiagem nos olhos (impossibilita a execução do exame); não compreensão ou dificuldade na execução das ordens do exame. Os pacientes foram divididos em Grupo A (7 a 19 anos) e Grupo B (20 a 59 anos). Todos foram avaliados por meio de exame otorrinolaringológico padrão do ambulatório, anamnese e vHIT. Os exames com valor de ganho superior a 0,8 foram considerados normais. Os canais com valores de ganho entre 0,6 e 0,8 foram classificados, nesta pesquisa, como limítrofe. Nos casos considerados limítrofes, foi analisado o valor da assimetria para diagnóstico, que foi considerada anormal acima de 20%. Para o cálculo amostral evidenciou que o número mínimo de indivíduos avaliados seria de, 10 sujeitos no grupo A e 20 sujeitos no grupo B. Resultados: a amostra total foi composta por 32 indivíduos. O grupo A foi formado por 11 indivíduos, com idade média de 12,7 ± 3,9 anos e o grupo B por 21 indivíduos, com idade média de 46,3 ± 11,1 anos. A análise dos resultados do vHIT revelou que não houve diferença significativa entre o lado considerado normal e o lado considerado afetado, considerando-se a análise intragrupo e entre grupos. Conclusão: a pesquisa evidenciou que, na amostra estudada, não houve diferença nos resultados obtidos no vHIT entre os lados afetados e não afetados pela OMCNC. / Objectives: To analyze the association between chronic otitis media (COM) without cholesteatoma and results in the video head impulse test (vHIT). Design: Cross sectional. Methods: The sample was selected in a specialized clinic of a university hospital. Patient inclusion in this study obeyed the following criteria: age between 7 and 59 years; diagnosis of unilateral COM without cholesteatoma with normal contralateral ear; not having done previous ear surgery; not having cognitive impairment and / or neurological and / or motor recorded in the medical records. The exclusion criteria were: patients with eye makeup, which cannot be removed (makes it impossible to perform the exam); patients who did not understand the operation of the test and therefore could not accomplish it. Patients were divided in group A (7 to 19) and group B (20 to 59) years of age. Both groups performed standard outpatient otolaryngology evaluation, clinical history and video head impulse test. Exams with a gain above 0.8 were considered normal. Canals gain values between 0.6 and 0.8 were classified in this study as borderline. In borderline cases considered, we analyzed the value of asymmetry for diagnosis, which was considered abnormal over 20%. For sample size calculation showed that the minimum number of individuals assessed was of 10 subjects in group A and 20 subjects in group B. Results: The total sample consisted of 32 individuals. Group A consisted of 11 subjects mean with an average age of 12.7 ± 3.9 years and the group B of 21 subjects with an average age of 46.3 ± 11.1 years. Analysis of the vHIT results showed no significant difference between the side considered normal and the side considered affected, considering the intra-group and between groups analysis. Conclusion: The research showed that, in our sample, there was no difference in the results obtained in vHIT between the affected side and the not affected by COM without cholesteatoma.

The aim of this thesis is to develop a novel technique for the estimation of firing rate dynamics from single-unit recordings of neural pulse trains. This method applies an offline digital filtering technique to extract information transmitted by a neuron in teens of a rate code. While there is increasing evidence that the traditional rate coding cannot account for all the information transmitted by a cell, and that information may also be contained in the precise timing of spikes, the firing rate signal remains the benchmark by which the vast majority of electrophysiological studies relating neural activity to functional behaviour have been interpreted. Nevertheless, there does not seem to be an agreement on a single definition of a rate code let alone a consensus on an optimal estimation method. This study raises significant concerns about the validity of some of the most common methods in systems neuroscience, and proposes a simple yet more robust alternative. This latter is based on the convolution of the spike train with an optimally designed Kaiser window. Using computer-simulated as well as experimental data obtained from single-unit recordings of vestibular canal afferents, the proposed technique is shown to consistently outperform the current methods and even to permit robust estimations under time-varying conditions. These results suggest that estimates acquired with the conventional methods are biased and hence models of neural dynamics based on these latter may not be reliable.

Objetivos: analisar a associação entre otite média crônica não colesteatomatosa (OMCNC) e os resultados obtidos no video head impulse test (vHIT). Delineamento: tipo transversal. Métodos: a amostra foi selecionada em ambulatório especializado de um hospital universitário. A inclusão dos pacientes neste estudo obedeceu aos seguintes critérios: idade entre 7 e 59 anos; diagnóstico de OMCNC unilateral, com orelha contralateral normal; não ter realizado cirurgia otológica prévia; não ter comprometimentos cognitivos e/ou neurológicos e/ou motores registrados nos prontuários. Os critérios de exclusão foram: impossibilidade de retirada de maquiagem nos olhos (impossibilita a execução do exame); não compreensão ou dificuldade na execução das ordens do exame. Os pacientes foram divididos em Grupo A (7 a 19 anos) e Grupo B (20 a 59 anos). Todos foram avaliados por meio de exame otorrinolaringológico padrão do ambulatório, anamnese e vHIT. Os exames com valor de ganho superior a 0,8 foram considerados normais. Os canais com valores de ganho entre 0,6 e 0,8 foram classificados, nesta pesquisa, como limítrofe. Nos casos considerados limítrofes, foi analisado o valor da assimetria para diagnóstico, que foi considerada anormal acima de 20%. Para o cálculo amostral evidenciou que o número mínimo de indivíduos avaliados seria de, 10 sujeitos no grupo A e 20 sujeitos no grupo B. Resultados: a amostra total foi composta por 32 indivíduos. O grupo A foi formado por 11 indivíduos, com idade média de 12,7 ± 3,9 anos e o grupo B por 21 indivíduos, com idade média de 46,3 ± 11,1 anos. A análise dos resultados do vHIT revelou que não houve diferença significativa entre o lado considerado normal e o lado considerado afetado, considerando-se a análise intragrupo e entre grupos. Conclusão: a pesquisa evidenciou que, na amostra estudada, não houve diferença nos resultados obtidos no vHIT entre os lados afetados e não afetados pela OMCNC. / Objectives: To analyze the association between chronic otitis media (COM) without cholesteatoma and results in the video head impulse test (vHIT). Design: Cross sectional. Methods: The sample was selected in a specialized clinic of a university hospital. Patient inclusion in this study obeyed the following criteria: age between 7 and 59 years; diagnosis of unilateral COM without cholesteatoma with normal contralateral ear; not having done previous ear surgery; not having cognitive impairment and / or neurological and / or motor recorded in the medical records. The exclusion criteria were: patients with eye makeup, which cannot be removed (makes it impossible to perform the exam); patients who did not understand the operation of the test and therefore could not accomplish it. Patients were divided in group A (7 to 19) and group B (20 to 59) years of age. Both groups performed standard outpatient otolaryngology evaluation, clinical history and video head impulse test. Exams with a gain above 0.8 were considered normal. Canals gain values between 0.6 and 0.8 were classified in this study as borderline. In borderline cases considered, we analyzed the value of asymmetry for diagnosis, which was considered abnormal over 20%. For sample size calculation showed that the minimum number of individuals assessed was of 10 subjects in group A and 20 subjects in group B. Results: The total sample consisted of 32 individuals. Group A consisted of 11 subjects mean with an average age of 12.7 ± 3.9 years and the group B of 21 subjects with an average age of 46.3 ± 11.1 years. Analysis of the vHIT results showed no significant difference between the side considered normal and the side considered affected, considering the intra-group and between groups analysis. Conclusion: The research showed that, in our sample, there was no difference in the results obtained in vHIT between the affected side and the not affected by COM without cholesteatoma.

Objetivos: analisar a associação entre otite média crônica não colesteatomatosa (OMCNC) e os resultados obtidos no video head impulse test (vHIT). Delineamento: tipo transversal. Métodos: a amostra foi selecionada em ambulatório especializado de um hospital universitário. A inclusão dos pacientes neste estudo obedeceu aos seguintes critérios: idade entre 7 e 59 anos; diagnóstico de OMCNC unilateral, com orelha contralateral normal; não ter realizado cirurgia otológica prévia; não ter comprometimentos cognitivos e/ou neurológicos e/ou motores registrados nos prontuários. Os critérios de exclusão foram: impossibilidade de retirada de maquiagem nos olhos (impossibilita a execução do exame); não compreensão ou dificuldade na execução das ordens do exame. Os pacientes foram divididos em Grupo A (7 a 19 anos) e Grupo B (20 a 59 anos). Todos foram avaliados por meio de exame otorrinolaringológico padrão do ambulatório, anamnese e vHIT. Os exames com valor de ganho superior a 0,8 foram considerados normais. Os canais com valores de ganho entre 0,6 e 0,8 foram classificados, nesta pesquisa, como limítrofe. Nos casos considerados limítrofes, foi analisado o valor da assimetria para diagnóstico, que foi considerada anormal acima de 20%. Para o cálculo amostral evidenciou que o número mínimo de indivíduos avaliados seria de, 10 sujeitos no grupo A e 20 sujeitos no grupo B. Resultados: a amostra total foi composta por 32 indivíduos. O grupo A foi formado por 11 indivíduos, com idade média de 12,7 ± 3,9 anos e o grupo B por 21 indivíduos, com idade média de 46,3 ± 11,1 anos. A análise dos resultados do vHIT revelou que não houve diferença significativa entre o lado considerado normal e o lado considerado afetado, considerando-se a análise intragrupo e entre grupos. Conclusão: a pesquisa evidenciou que, na amostra estudada, não houve diferença nos resultados obtidos no vHIT entre os lados afetados e não afetados pela OMCNC. / Objectives: To analyze the association between chronic otitis media (COM) without cholesteatoma and results in the video head impulse test (vHIT). Design: Cross sectional. Methods: The sample was selected in a specialized clinic of a university hospital. Patient inclusion in this study obeyed the following criteria: age between 7 and 59 years; diagnosis of unilateral COM without cholesteatoma with normal contralateral ear; not having done previous ear surgery; not having cognitive impairment and / or neurological and / or motor recorded in the medical records. The exclusion criteria were: patients with eye makeup, which cannot be removed (makes it impossible to perform the exam); patients who did not understand the operation of the test and therefore could not accomplish it. Patients were divided in group A (7 to 19) and group B (20 to 59) years of age. Both groups performed standard outpatient otolaryngology evaluation, clinical history and video head impulse test. Exams with a gain above 0.8 were considered normal. Canals gain values between 0.6 and 0.8 were classified in this study as borderline. In borderline cases considered, we analyzed the value of asymmetry for diagnosis, which was considered abnormal over 20%. For sample size calculation showed that the minimum number of individuals assessed was of 10 subjects in group A and 20 subjects in group B. Results: The total sample consisted of 32 individuals. Group A consisted of 11 subjects mean with an average age of 12.7 ± 3.9 years and the group B of 21 subjects with an average age of 46.3 ± 11.1 years. Analysis of the vHIT results showed no significant difference between the side considered normal and the side considered affected, considering the intra-group and between groups analysis. Conclusion: The research showed that, in our sample, there was no difference in the results obtained in vHIT between the affected side and the not affected by COM without cholesteatoma.

No description available.

Made available in DSpace on 2015-07-22T20:49:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-01-26 / Objetivo: comparar o nistagmo pós-calórico da prova com ar a 50 e 24°C com o da prova com água a 44 e 30°C. Método: estudo transversal controlado em 40 indivíduos hígidos, sem sintomas e sinais de alteração da audição e do equilíbrio corporal e que não estavam fazendo uso de medicamentos. Os indivíduos foram instruídos quanto ao preparo do exame e submetidos à avaliação vestibular incluindo a prova calórica com ar a 50 e 24°C e com água a 44 e 30°C. Os mesmos foram distribuídos de forma aleatória em dois grupos, segundo a ordem de estimulação calórica, ora iniciando com ar, ora com água. Resultados: À comparação das provas com ar e com água, não houve diferença significante entre os valores da velocidade angular da componente lenta (VACL) do nistagmo pós-calórico quanto à ordem de realização das estimulações, entre as orelhas e entre os valores de predomínio labiríntico e de preponderância direcional. Os valores de VACL foram maiores nas estimulações com água do que com ar (p=0,008; p<0,001). A temperatura fria evocou respostas mais intensas do que a temperatura quente nas provas com ar e com água (p<0,001). Conclusão: A prova calórica com água apresenta valores de VACL maiores do que a prova calórica com ar, mas ambas as provas apresentam semelhança nos valores da VACL maiores na temperatura fria e nos resultados dos valores relativos de predomínio labiríntico e preponderância direcional do nistagmo. / Purpose: to compare the nystagmus response in air (50°C/24°C) and water (44°C/30°C) caloric tests. Method: controlled cross-sectional study in 40 healthy individuals without any symptoms or signs of either hearing or balance disorders who were not making use of any medications. The individuals underwent an otoneurological evaluation, including air (50°C/24°C) and water (44°C/30°C) caloric tests. Results: Comparing air and water caloric tests, no significant difference was found among the values of slow-phase velocity post-caloric nystagmus regarding the stimulation order, between ears and between the values of unilateral weakness and directional preponderance. Slow-phase velocity values were higher in water than in air stimulation (p=0.008, p<0.001). Cold stimulation evoked more intense responses than warm stimulation in both air and water tests (p<0.001). Conclusion: In air (50°C/24°C) and water (44°C/30°C) caloric tests, the post-caloric nystagmus is similar in terms of slow-phase velocity values in both ears, higher responses in the cold temperature, unilateral weakness and directional preponderance results but it is different with regard to slow-phase velocity values which are higher in water test. / TEDE / BV UNIFESP: Teses e dissertações