Signal processing in the visual system is mediated by classic neurotransmission and neuropeptidergic modulatory pathways. In Dipteran insects, especially in the fruitfly Drosophila melanogaster, the morphology of the visual system is very well described. However neurotransmitter and neuropeptidergic circuits within the optic lobe neuropil are only partially known. Using several transgenic fly lines and antibodies we determined the localization of the classical neurotransmitters GABA, acetylcholine and glutamate in the visual system, and their putative targets via detecting several neurotransmitter receptors. We paid particular attention to the peripheral neuropil layer called the lamina, where the light signals are filtered, channeled and amplified (Paper I). We discovered four new types of efferent tangential neurons branching distally to the lamina. Among them was the first neuropeptidergic neuron (LMIo) in this region of Drosophila. The LMIo expresses myoinhibitory peptide (MIP) and has its cell body located close to the main lateral clock neurons that express the neuropeptide pigment-dispersing factor (PDF)(Paper II). Since in other Dipteran species PDF is expressed in processes distally to the lamina, we performed comparative anatomical studies of the MIP, PDF, Ion Transport Peptide (ITP) and serotonin (5-HT) distribution in the visual system of the flies Drosophila and Calliphora. Our data suggest that PDF signaling distal to the lamina of the blowfly might be replaced by MIP signaling in the fruitfly, while ITP and 5-HT expression is conserved in the two species (Paper III). Serotonin is crucial in light adaptation during the daily light-dark cycles. We analyzed putative serotonergic circuits in the lamina. We found that LMIo neurons express the inhibitory receptor 5-HT1A, while 5-HT1B and 5-HT2 are both expressed in the epithelial glia of the lamina. Another novel wide-field neuron with lamina branches expresses the excitatory serotonin receptor 5-HT7. Our studies have identified a fairly complex neuronal circuitry in the tangential plexus above the lamina. (Paper IV). Finally we tested circadian locomotor activity rhythms in flies with the GABAB receptor knocked down on the lateral PDF-expressing clock neurons. We observed significant changes in the activity periods and diminished strength of rhythmicity during DD suggesting a modulatory role of GABA in clock function (Paper V). / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.

Defining language lateralisation is important to minimise morbidity in patients treated surgically for temporal lobe epilepsy (TLE). Functional magnetic resonance imaging (fMRI) offers a promising, non-invasive, alternative strategy to the Wada test. Here, fMRI has been used to study healthy controls and patients with TLE in order (i) to define language-related activation patterns and their reproducibility; (ii) to compare lateralisation determined by fMRI with that from the Wada test; and (iii) to explore the usefulness of multiple fMRI language paradigms. 18 healthy controls (12 right-handed and 6 left-handed) and 24 pre-operative TLE patients (19 right-handed: 12 left-TLE, 7 right-TLE; 5 left-handed: 2 right-TLE, 3 left-TLE) were studied using fMRI. Four fMRI language paradigms used: phonetic and semantic fluency, and the naming of living and non-living things. The data for all 4 tasks were acquired during a single scanning session on two occasions. All patients also underwent Wada testing. In patients and controls, phonetic and semantic fluency tasks were robustly activating and strongly lateralising. Quantified language-related lateralisation from fMRI verbal fluency data was highly reproducible and concordant with the lateralisation of the Wada test. Both fluency tasks identified patients with atypical language lateralisation, including 4/12 right-handed patients with left-TLE and 4/5 left-handed TLE patients, regardless of the side of epileptic focus. In comparison, the two confrontational naming tasks were not strongly lateralising and did not reliably agree with Wada lateralisation in either 12 right-handed controls or 19 right-handed patients with TLE. However, there was a difference in the pattern of fMRI activation in right-handed pat ients with left-TLE. Left-TLE patients had a more right lateralised network of activation when naming living things relative to non-living things, suggesting that some patients may be at risk of a category specific naming decline for non-living things after left anterior temporal lobectomy. These results demonstrate that non-invasive fMRI measures of languagerelated lateralisation may provide a practical and reliable alternative to invasive testing for pre-surgical language lateralisation in patients with TLE. The high proportion of TLE patients showing atypical language lateralisation suggests considerable plasticity of language representation in the brains of patients with intractable TLE.

Defining language lateralisation is important to minimise morbidity in patients treated surgically for temporal lobe epilepsy (TLE). Functional magnetic resonance imaging (fMRI) offers a promising, non-invasive, alternative strategy to the Wada test. Here, fMRI has been used to study healthy controls and patients with TLE in order (i) to define language-related activation patterns and their reproducibility; (ii) to compare lateralisation determined by fMRI with that from the Wada test; and (iii) to explore the usefulness of multiple fMRI language paradigms. 18 healthy controls (12 right-handed and 6 left-handed) and 24 pre-operative TLE patients (19 right-handed: 12 left-TLE, 7 right-TLE; 5 left-handed: 2 right-TLE, 3 left-TLE) were studied using fMRI. Four fMRI language paradigms used: phonetic and semantic fluency, and the naming of living and non-living things. The data for all 4 tasks were acquired during a single scanning session on two occasions. All patients also underwent Wada testing. In patients and controls, phonetic and semantic fluency tasks were robustly activating and strongly lateralising. Quantified language-related lateralisation from fMRI verbal fluency data was highly reproducible and concordant with the lateralisation of the Wada test. Both fluency tasks identified patients with atypical language lateralisation, including 4/12 right-handed patients with left-TLE and 4/5 left-handed TLE patients, regardless of the side of epileptic focus. In comparison, the two confrontational naming tasks were not strongly lateralising and did not reliably agree with Wada lateralisation in either 12 right-handed controls or 19 right-handed patients with TLE. However, there was a difference in the pattern of fMRI activation in right-handed pat ients with left-TLE. Left-TLE patients had a more right lateralised network of activation when naming living things relative to non-living things, suggesting that some patients may be at risk of a category specific naming decline for non-living things after left anterior temporal lobectomy. These results demonstrate that non-invasive fMRI measures of languagerelated lateralisation may provide a practical and reliable alternative to invasive testing for pre-surgical language lateralisation in patients with TLE. The high proportion of TLE patients showing atypical language lateralisation suggests considerable plasticity of language representation in the brains of patients with intractable TLE.

Licentiatavhandling (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 2 uppsatser.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2008. / Härtill 4 uppsatser.

Zugl.: Habil'schrift Bern.

Thesis (Ph. D.)--Cornell University, May, 2008. / Vita. Includes bibliographical references (leaves 147-159)

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 189-196).

Orientadores: Fernando Cendes, Íscia Lopes-Cendes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T00:02:21Z (GMT). No. of bitstreams: 1 Bilevicius_Elizabeth_D.pdf: 3815616 bytes, checksum: 984636c562a41b059889857b7a8b2037 (MD5) Previous issue date: 2011 / Resumo: O objetivo foi realizar uma análise multifatorial dos aspectos clínicos e de ressonância magnética (quantitativos e qualitativos) relacionados à resistência ao tratamento com drogas anti-epilépticas (DAES) em pacientes com epilepsia de lobo temporal mesial e melhor caracterizar o grupo de resposta intermediário a DAES, aqui denominado remitente-recorrente. Foram incluídos 165 pacientes e divididos em 3 grupos de acordo com a resposta medicamentosa: 50 respondedores (31 mulheres) , 87 não respondedores ao uso de DAES (53 mulheres) e 28 remitentes-recorrentes (17 mulheres) . Estes foram avaliados quanto à idade, freqüência de crises e idade no início destas, presença de crises febris, presença e lateralidade da atrofia hipocampal à análise visual, fatores precipitantes e DAES utilizadas. A quantificação dos volumes hipocampais foi realizada através de volumetria manual pelo software DISPLAY e as comparações dos volumes médios de ambos os hipocampos foi realizada entre os 3 grupos e 30 controles sadios por ANOVA. As imagens de ressonância magnética também foram avaliadas através da técnica de Morfometria Baseada em Voxel (VBM) com o software SPM 5 (Statistical Parametric Mapping)/MATLAB 7.7.0, comparando os três grupos com 75 indivíduos normais e entre si através de Teste -T. Observamos que idade de início das crises foi menor (p=0,005) e a freqüência das crises ao início foi maior (p=0,018) em farmacorresistentes quando comparado aos outros 2 grupos. As DAES mais utilizadas foram a carbamazepina e o clobazam (em associação) em todos os grupos. As doses de carbamazepina utilizadas foram maiores em farmacorresistentes (p<0,001) e remitentes-recorrentes (p=0,02) em comparação aos responsivos. Em relação ao clobazam, observamos dose significativamente maior somente nos farmacorresistentes em comparação aos outros dois grupos (p=0,017). A comparação da média dos volumes hipocampais entre os 3 grupos e controle evidenciou diferenças somente entre farmacorresistentes e controles bilateralmente (esquerda ,p = 0,004; direita, p=0,02). A análise por VBM evidenciou atrofia de substância cinzenta em todos os grupos. No grupo farmacorresponsivo tal atrofia foi mais restrita a áreas ipsilaterais ao foco epileptigênico, ao passo que nos grupos farmacorresistente e remitente-recorrente esta atrofia apresentou-se mais difusa. A comparação entre os grupos evidenciou as seguintes áreas com maior redução de substância cinzenta nos grupos farmacorresistente e remitenterecorrente quando comparados aos farmacorresponsivos: frontal periorbital bilateral (p<0,01), cíngulo (p<0,05) e temporal contralateral ao foco epileptogênico (p<0,05). Desta forma, observamos que embora as características clínicas demonstrassem mais similaridades entre os grupos respondedor e remitente-recorrente, a análise de VBM mostrou redução de substância cinzenta mais difusa em farmacorresistentes e remitentesrecorrentes. Assim pudemos observar que as variáveis clínicas relacionadas ao pior prognóstico foram idade e freqüência de início de crises. Em relação às variáveis estruturais, embora a atrofia de substância cinzenta (SC) se apresentasse mais difusamente em pacientes de pior resposta medicamentosa, também ocorre em áreas extra-hipocampais e mesmo extratemporais em pacientes considerados farmacorresponsivos mesmo que ipsilateralmente ao foco epileptogênico. Por último, conseguimos caracterizar clínica e estruturalmente o grupo remitente-recorrente, observado na prática clínica, porém até então muito pouco reconhecido na literatura / Abstract: The objective of the present work was to investigate the relationship between brain MRI and clinical characteristics and patterns of antiepileptic drug (AED) response in patients with mesial temporal lobe epilepsy (MTLE).In order to do that,one hundred sixty five MTLE patients were divided into seizure-free with AED (50 AEDresponders, 31 women), 87 pharmacoresistants (53 women), and 28 remitting-relapsing seizure control group (17 women). All groups were evaluated regarding age, frequency of seizures and age at epilepsy onset, duration of epilepsy, febrile seizures (FS), presence and side of hippocampal atrophy on visual inspection (HA), initial precipitating injuries (IPIs), type and quantity of AEDS used. The right and left hipoccampi from 99 patients belonging to all three groups (43 pharmacoresistants, 31 pharmacoresponsive and 25 remitting-relapsing subjects). were submitted to manual morphometry by DISPLAY software (Brain Imaging Centre, Montreal, Canada) as well as hipoccampi selected from 30 healthy controls. The calculated mean from those hipoccampi were compared within subjects and with controls. For gray matter (GM) MRI voxel-based morphometry (VBM) we selected only patients with unilateral HA on visual MRI analysis (n=100). Comparisons were made between all groups and 75 healthy controls. Age at epilepsy onset was lower (p=0,005) and initial frequency of seizures was higher in pharmacoresistants compared with the other two groups (p=0,018). The most used AEDS were carbamazepine and clobazam (always in association). The highest carbamazepine dose was observed in pharmacorresistants (p<0,001) and remitting-relapsing group (p=0,02). The highest dose of clobazam occurred only in pharmacoresistant group (p=0,017). The comparison between the mean hippocampi volumes from three groups and controls showed differences only on the pharmacoresistants left (p=0,004) and right(p=0,02) hippocampus comparing to controls. All groups showed GM atrophy compared to controls in ipsilateral hippocampus, bilateral parahippocampal gyri, frontal, occipital, parietal and cerebellar areas. In the AED-responders group such findings were more restricted to areas ipsilateral to the epileptic focus and more widespread in pharmacoresistants and remitting-relapsing groups. VBM pairwise comparisons showed areas with GM volume reduction in pharmacoresistants and remitting-relapsing compared with AED-responders in bilateral periorbital frontal (p< 0,01), cingulum (p<0,05), and temporal lobe contralateral to the epileptic focus (p< 0,05). We may conclude that, pharmacoresistants and remittingrelapsing patients presented a similar pattern of GM atrophy which was more widespread compared with AED-responders on VBM. We could also observe that age at epilepsy onset was lower (p=0,005) and initial seizure frequency was higher in pharmacoresistants / Doutorado / Neurociencias / Doutor em Ciências

Orientador: Fernando Cendes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-13T01:46:44Z (GMT). No. of bitstreams: 1 Campos_BrunoAugustoGoulart_M.pdf: 774663 bytes, checksum: ef708c3035e1e8aaca7bef6613de3b28 (MD5) Previous issue date: 2009 / Resumo: Objetivos: Comparar as medidas relativas de N-Acetil Aspartato (NAA) em pacientes com epilepsia do lobo temporal (ELT) entre aqueles com resposta adequada a primeira droga anti-epiléptica (DAE) com aqueles que não responderam a primeira DAE, requerendo outra monoterapia ou politerapia. Métodos: Nós estudamos 27 indivíduos no grupo-controle, 25 pacientes com ELT com resposta a primeira DAE (grupo-resposta) e 21 que não responderam a primeira DAE (grupo-falência) e que eram regularmente acompanhadas no nosso serviço de epilepsia. Todos foram submetidos a estudo por imagem e espectroscopia pela RNM e a razão NAA/Creatina foi calculada. Resultados: A razão NAA/Creatina foi testada por análise de variância (ANOVA) entre os grupos, mostrando uma significativa redução tanto no hipocampo ipsilateral quanto no contralateral relacionado ao EEG (p<0,001 e p=0,021 respectivamente). A análise post hoc não mostrou diferença significativa entre o grupo-resposta e o grupo-controle, mas com diferença entre o grupo-falência e os outros grupos. A análise individual mostrou uma redução maior que dois desvios-padrão abaixo da média dos controles em nove dos 21 (42,8%) pacientes no grupo-falência, mas em nenhum dos pacientes no grupo-resposta. Discussão: Nosso trabalho mostrou uma redução significativa na razão NAA/Cre no grupo com falência à primeira DAE, mas não no grupo com que apresentou resposta à primeira DAE comparado aos indivíduos do grupo controle. Estes resultados indicam que pacientes com ELT com resposta à primeira DAE têm menos evidência de dano ou disfunção neuronal/axonal comparado a aqueles refratários a primeira DAE. / Abstract: Purpose: To compare relative N-acetylaspartate (NAA) measurements in temporal lobe epilepsy (TLE) patients with good response to the first trial of AED (an important prognostic factor) to TLE patients who failed the first AED trial and required further AED trials with monotherapy or polytherapy. Methods: We studied 27 individuals in control-group, 25 TLE patients who responded to the first AED (response-group) and 21 who did not (failure-group) that were regularly seen at our Epilepsy Service. They were submitted to both MRI and proton spectroscopy, and NAA/Creatine ratio calculated. Results: ANOVA of NAA/Cre demonstrated significant reduction in both ipsilateral and contralateral hippocampus related to EEG focus (p<0.001 and p=0.021), and post hoc analysis of ipsilateral and contralateral hippocampus did not reach statistic significance between response-group and control-group, but we found difference between failuregroup and the others groups. Individual analysis showed NAA/Cre ratios lower than 2 SD below the mean of controls in nine of 21 (42.8%) patients in the first AED failure group (six with unilateral and three with bilateral NAA/Cre reduction) but in none of patients who responded to first AED. Discussion: Our study demonstrated observed in refractory and mild TLE patients with HA. These results indicates that patients with TLE who respond well to first AED have significantly less evidence of neuronal and axonal damage/dysfunction compared to those who are refractory to first AED. / Mestrado / Neurociencias / Mestre em Fisiopatologia Médica