Diss. (sammanfattning) Stockholm : Karol inst., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 5 uppsatser.

Thesis (Ph. D.)--Cornell University, May, 2008. / Vita. Includes bibliographical references (leaves 143-165).

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-15T14:05:59Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_AndersonFelipe_Versão Final.pdf: 4770513 bytes, checksum: bd8c869ddc087cfbf7bc953f303cf9e5 (MD5) / Made available in DSpace on 2016-04-15T14:05:59Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_AndersonFelipe_Versão Final.pdf: 4770513 bytes, checksum: bd8c869ddc087cfbf7bc953f303cf9e5 (MD5) Previous issue date: 2015-08-21 / A desnutrição durante o período perinatal tem sido associada a aumento da compulsão alimentar, preferência por alimentos palatáveis e risco de desenvolvimento de obesidade na vida adulta. O apetite é controlado por vários sistemas fisiológicos, dentre os quais o sistema neural de recompensa. A dopamina é um conhecido neurotransmissor deste sistema, estando envolvida nas relações de prazer proporcionado por alimentos e drogas, agindo através da ligação em receptores neuronais, de duas classes: D1-like e D2-like. O objetivo deste trabalho foi avaliar a expressão dos receptores dopaminérgicos D1 no Núcleo Accumbens e estriado, áreas relacionadas ao comportamento alimentar, em ratas desnutridas. Dois grupos experimentais foram formados: grupo-controle (CF - fêmeas gestadas por mães normonutridas durante a gestação e lactação) e grupo-desnutrido (DF - fêmeas gestadas por mães que receberam dieta hipoprotéíca no período perinatal). Os animais passaram a receber dieta-padrão de laboratório após o desmame e tiveram o peso avaliado em diferentes momentos da vida. No 120º dia, foram sacrificadas e submetidas à perfusão, para retirada dos encéfalos. Após os cortes dos cérebros em micrótomo de congelamento, procedeu-se a Imunohistoquímica para contagem de neurônios marcados para DRD1. As imagens foram obtidas através de câmera acoplada ao microscópio óptico e a morfometria realizada no software livre ImageJ. Os dados estatísticos foram expressos em média±desvio-padrão, sendo analisados no software livre GraphPad Prism 5. Os animais desnutridos apresentaram menor peso em relação aos normonutridos desde o nascimento até o sacrifício. Não foi encontrada diferença significativa entre os grupos na expressão de DRD1 nas áreas cerebrais analisadas (Estriado: CF: 230,0 ± 86,40, n=4; DF: 225,50 ± 89,90, n=4; Núcleo Accumbens: CF: 109,80 ± 41,40, n=4; DF: 128,0 ± 49,50, n=5; test t de Student, p<0,05). Estes dados sugerem que a expressão dos receptores D1 está diretamente relacionada à quantidade de dopamina liberada na fenda sináptica, quantidade essa que é maior na apresentação de alimentos novos e palatáveis. / Malnutrition during the perinatal period has been linked to increased binge eating, preference for palatable foods and risk of obesity developing in adulthood. Appetite is controlled by several physiological systems, including the neural reward system. Dopamine is a neurotransmitter in this system and it is involved in relations of pleasure provided by foods and drugs, acting through its binding to neuronal receptors of two classes: D1-like and D2-like. The goal of this study was to evaluate the expression of dopamine D1 receptors in the striatum and Nucleus Accumbens, areas related to feeding behavior, in malnourished rats. Two experimental groups were formed: the control group (CF - rats coming from normonutridas mothers during pregnancy and lactation) and group-malnourished (DF - coming rats of mothers who received low protein diet during the perinatal period). The animals began to receive standard laboratory diet after weaning and had the weight assessed at different times of life. In 120 days, they were sacrificed and submitted to perfusion, to remove the brains. After the cuts of the brains in freezing microtome, it proceeded to Immunohistochemistry for counting neurons marked for DRD1. The images were obtained through camera coupled to an optical microscope and morphometry performed on the Free Software ImageJ. Statistical data were expressed as mean ± standard deviation and analyzed the free software GraphPad Prism 5. Malnourished animals showed lower weight compared to well-nourished from birth to the sacrifice. There was no significant difference between groups in the expression of DRD1 the analyzed brain areas (Striatum: CF: 230.0 ± 86.40, n = 4; DF: 225.50 ± 89.90, n = 4; Nucleus Accumbens: CF: 109.80 ± 41.40, n = 4; DF: 128.0 ± 49.50, n = 5; Student's t test, p <0.05). These data suggest that the expression of D1 receptors is directly related to the amount of dopamine released in the synaptic cleft, which amount is higher in presenting new and palatable food.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24499号 / 医博第4941号 / 新制||医||1064(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊藤 貴浩, 教授 中島 貴子, 教授 藤田 恭之 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

The induction of synaptic plasticity at CA1 synapses requires NMDAR activation. Modulation of NMDAR function by various GPCRs can shift the thresholds for LTP and LTD induction and contribute to metaplasticity. Here we showed that the activity of GluN2A- and GluN2B-containing NMDARs is differentially regulated by Gαi/o-coupled, Gαq- and Gαs-coupled receptors. Furthermore, enhancing the relative function of GluN2A-to-GluNB NMDAR activity by GPCRs can alter the balance of LTP and LTD induction and contribute to metaplasticity. In CA1 neurons, activation of the Gαs-coupled D1/D5R selectively recruited Fyn kinase and enhanced GluN2B-mediated NMDAR currents. Biochemical experiments confirmed that D1/D5R stimulation activates Fyn kinase and enhances the tyrosine phosphorylation of GluN2B subunits. In contrast, activation of the Gαq-coupled PAC1R selectively recruited Src kinase to enhance the function of GluN2A-containing NMDARs. Enhancing the functional ratio of GluN2A-to-GluN2B subunits by PAC1R activation lowered the threshold for LTP induction whereas enhancing the functional ratio of GluN2B-to-GluN2A subunits by D1/D5R activation increased the threshold for LTP induction. Unexpectedly, activation of the Gαi/o-coupled mGluR2/3 enhanced NMDAR-mediated function via a previously unidentified mechanism. Inhibition of the cAMP-PKA pathway via mGluR2/3 activation resulted in activation of Src via decreased phosphorylation of its C-terminal Tyr527 by Csk. Stimulation of mGluR2/3 selectively potentiated the function of GluN2A-containing NMDARs but whether it shifted the modification threshold θm to the left requires further investigation.

The induction of synaptic plasticity at CA1 synapses requires NMDAR activation. Modulation of NMDAR function by various GPCRs can shift the thresholds for LTP and LTD induction and contribute to metaplasticity. Here we showed that the activity of GluN2A- and GluN2B-containing NMDARs is differentially regulated by Gαi/o-coupled, Gαq- and Gαs-coupled receptors. Furthermore, enhancing the relative function of GluN2A-to-GluNB NMDAR activity by GPCRs can alter the balance of LTP and LTD induction and contribute to metaplasticity. In CA1 neurons, activation of the Gαs-coupled D1/D5R selectively recruited Fyn kinase and enhanced GluN2B-mediated NMDAR currents. Biochemical experiments confirmed that D1/D5R stimulation activates Fyn kinase and enhances the tyrosine phosphorylation of GluN2B subunits. In contrast, activation of the Gαq-coupled PAC1R selectively recruited Src kinase to enhance the function of GluN2A-containing NMDARs. Enhancing the functional ratio of GluN2A-to-GluN2B subunits by PAC1R activation lowered the threshold for LTP induction whereas enhancing the functional ratio of GluN2B-to-GluN2A subunits by D1/D5R activation increased the threshold for LTP induction. Unexpectedly, activation of the Gαi/o-coupled mGluR2/3 enhanced NMDAR-mediated function via a previously unidentified mechanism. Inhibition of the cAMP-PKA pathway via mGluR2/3 activation resulted in activation of Src via decreased phosphorylation of its C-terminal Tyr527 by Csk. Stimulation of mGluR2/3 selectively potentiated the function of GluN2A-containing NMDARs but whether it shifted the modification threshold θm to the left requires further investigation.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

The process of receptor supersensitivity (RSS) has a long history and is an epiphenomenon of neuronal denervation. Dopamine (DA) RSS (DARSS) similarly occurs after DA denervation, and this process is invoked in neuropsychiatric and neurodegenerative disorders. From studies largely over the past 25 years, much has been learned regarding DARSS. For example, overt D1 DARSS occurs after perinatal destruction of nigrostriatal DA fibers. However, following perinatal destruction of DA innervation, the most-prominent behavioral effects of a D1 agonist are observed after a series of D1 agonist treatments--a process known as priming of D1 DA receptors. Moreover, perinatal lesioning of DA fibers produces prominent serotonin (5-HT) RSS, and in fact 5-HT RSS appears to modulate D1 DA RSS. In rodents, receptor supersensitization by these means appears to be irreversible. In contrast to the observed D1 DARSS, D2 DARSS apparently does not occur after perinatal DA denervation. Also, while repeated D1 agonist treatment of intact rats has no observable effect, repeated D2 agonist treatments, during or after the ontogenetic phase, produces prominent life-long D2 RSS. The process may have an association with substance abuse. Therefore, production of D1 and D2 DARSS occurs by different means and under different circumstances, and in association with perhaps different neuronal phenotypes, and with greater incidence in either intact (D2) or DA-lesioned counterparts (D1). The physiological consequence of RSS are multiple.

No description available.