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Schizophrenia is among the most debilitating mental disorders, yet the pathophysiology remains unclear. The basal ganglia, a region of the brain involved in motor, cognitive, and sensory processes, may be involved in the pathophysiology of schizophrenia. Some, but not all, neuroimaging studies suggest abnormalities of the basal ganglia in schizophrenia. However, previous studies have examined whole basal ganglia nuclei as opposed to using a unified basal ganglia complex that incorporates anterior-posterior divisions, dorsal-ventral divisions, and gray-white matter segmentation. The hypothesis for the present study was that basal ganglia sub-regions forming functionally relevant subdivisions might be different in schizophrenia. Magnetic resonance imaging scans were acquired from 25 first-episode schizophrenia subjects and 24 healthy subjects. Using manual and automated neuroimaging techniques, total and segmented (gray-white matter) volumes were obtained for the caudate, putamen, and globus pallidus. For the striatum (caudate and putamen), total and segmented volumes were obtained for their respective sub-regions. These sub-regions were restructured into associative, limbic, and sensorimotor subdivisions. Schizophrenia subjects had 6% smaller gray matter volumes for the caudate and 8% smaller gray matter volumes for the associative striatum relative to healthy subjects. Basal ganglia function was studied by examining performance on a neuropsychological test that assesses frontostriatal functioning. For male subjects there was a significant negative correlation between volume of the associative striatum and performance on the neuropsychological test (r=-0.57, p=0.03). Smaller volumes of the associative striatum were associated with more errors on the neuropsychological test. This test was specific to the associative striatum, as another neuropsychological test did not reveal any correlation. In schizophrenia subjects, the relationship between basal ganglia volumes and motor symptoms severity was examined. For antipsychotic-naive subjects there was a significant negative correlation between volume of the motor striatum and severity of Parkinsonism (r=-0.65, p=0.03). The present study suggests that total basal ganglia nuclei volumes are not different in schizophrenia, but gray matter volumes of total basal ganglia nuclei and subdivisions forming functional units may be different in schizophrenia. Structural abnormalities involving the basal ganglia may lead to disrupted functional circuits in schizophrenia. / Medicine, Faculty of / Graduate

G proteins are alpha-beta-gamma heterotrimers in the resting state, bound to GDP and complexed with the unbound receptor. Once the receptor becomes occupied, the alpha subunit exchanges GDP for GTP, becomes activated, and dissociates from the receptor and can stimulate or inhibit many intracellular activities such as phosphorylation and channel conductance. For example, Gs and Golf alpha subunits stimulate and Gi alpha subunits inhibit adenylyl cyclase. Go alpha subunits are abundant in brain, but are of unknown function. cDNAs for the alpha subunit have been cloned. In order to examine the relative distributions of G proteins in the brain, we used in situ hybridization with radiolabelled synthetic oligonucleotide probes. By using a tyrosine hydroxylase antibody, we found that the dopaminergic neurons of the substantia nigra and the noradrenergic neurons of the locus ceruleus express mRNA for the alpha subunits for each of Gi, Go, and Gs. We noted a paucity of Gs mRNA in the striatum. This was surprising because the basal ganglia contain a dopamine-stimulated adenylyl cyclase activity which has been assumed to be transduced by Gs. Also, immunohistochemistry, immunoblotting, and cholera ADP-ribosylation indicated a very high level of Gs alpha-like protein in the striatum. In order to ascertain which specific G protein we were detecting, we made probes to a new G protein previously identified in the olfactory system. Golf is a stimulatory G protein with size and sequence characteristics similar to those of Gs. The cholera toxin ADP-ribosylation site and C-terminal region to which the antibody was made are identical. We made oligonucloetide probes to the translated and untranslated portions of Golf alpha. High levels Golf mRNA and protein were detected in the striatum and nucleus accumbens, in addition to the expected high levels in the olfactory tubercle. Northern blot studies indicated that Golf transcripts are approximately ten-fold more abundant than Gs alpha transcripts in the striatum. These data indicate that Golf in not an olfactory-specific G protein. It is also the major stimulatory G protein in the basal ganglia. The selective expression of high levels of Golf in dopamine-rich forebrain areas suggest that it may couple DI dopamine receptors to adenylyl cyclase. The role of Golf in dopaminergic neurotransmission and neuropsychiatric disease should be considered. / Medicine, Faculty of / Graduate

Orientador: Ricardo de Lima Zollner / Tese (doutorado) - Universidde Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-07-20T11:14:07Z (GMT). No. of bitstreams: 1 Pavin_ElizabethJoao_D.pdf: 3589509 bytes, checksum: 84c167e3a4d2d2f0430ba93886105632 (MD5) Previous issue date: 1995 / Resumo: A excreção urinária de componentes da membrana basal, especificamente colágeno IV e laminina, foi determinada através de "immunoblotting", e estudada em ratos Wistar machos, diabéticos-induzido por drogas (aloxana e estreptozotocina) EV, e comparada a controles, em função do tempo de doença. Estudamos, também, as funções renais: glomerular e tubular, avaliando, respectivamente, clearance de creatinina e de lítio. Além disso, aspectos morfológicos renais foram analisados utilizando-se técnicas de PAS e de imuno-histoquímica, para colágeno IV e laminina, com o objetivo de verificar possíveis alterações da membrana basal. Assim, pudemos observar excreções de frações urinárias de colágeno IV (88 e 75 kDa) e laminina (108 e 88 kDa), em ambos os modelos de DM, em todos os tempos estudados. Entretanto, a fração de 57 kDa da laminina, nos animais diabéticos-induzido por estreptozotocina, somente foi expressa a partir da 5a semana de doença, enquanto nos diabéticos- induzido por aloxana sua excreção foi verificada precocemente (2º dia). As alterações da função renal foram semelhantes nos dois modelos, porém de maneira mais intensa no modelo aloxânico. Dentre elas destacaram-se: diminuição progressiva da taxa de filtração glomerular, aumento da fração de excreção de sódio; e, diminuição da reabsorção proximal deste ion, não compensada por aumento da reabsorção distai. Os achados morfológicos evidenciaram espessamento da membrana basal do capilar glomerular e aumento da matriz mesangial, iniciando-se precocemente no diabetes melliíus aloxânico. De acordo com os dados observados neste estudo, concluímos que no DM induzido por aloxana e estreptozotocina, frações urinárias de colágeno IV e laminina podem ser utilizadas como marcadores precoces de nefropatia diabética. Outrossim, o DM induzido por aloxana promove alterações funcionais renais mais intensas, principalmente tubulares, quando comparado ao modelo induzido por estreptozotocina; em adição, as alterações morfológicas observadas pela técnica de imuno-histoquímica puderam ser correlacionadas às alterações bioquímico-funcionais-renais / Abstract: The urine excretion of basement membrane components, specifically collagen IV and laminin, was determinated by immunoblotting and analyzed in male diabetic Wistar rats diabetic-induced (alloxan and streptozotocin) and compared to controls, considering the disease period. We also studied the renal functions: glomerular and tubular, evaluating creatinine and lithium clearance, respectively Moreover morphological renal aspects were analyzed by using PAS and immunohistochemical staining, for collagen IV and laminin, with the purpose of examining possible alterations at the basement membrane. In this way, we could observe urine fractions excretions of collagen IV (88, 75 kDa) and laminin (108, 88 kDa), in both DM models, in all periods of study. However the laminin fraction of 57 kDa, in the streptozotocin-induced diabetic animals, was expressed only from the 5th week of the disease, while in the alloxan-induced diabetic animals their excretion was verified earlier (on the 2nd. day). The renal function alterations were similar in the two models, but with more intensity in the alloxan model. Among them we can underline following; progressive decrease of the glomerular filtration rate, increase of the fractional sodium excretion and decrease of the proximal reabsorption of this ion, not compensated by distal reabsorption increase. The morphological findings showed a thickness of the capilar glomerular basement membrane and an increase of the mesangial matrix, beginning earlier at the alloxanic diabetes mellUus. In accordance with the data observed in this study, we conclude that at the alloxan and streptozotocin induced DM, urine fractions of collagen IV and laminin can be used as early markers of diabetic nephropathy. Besides this, the alloxan-induced DM produces functional renal alterations with more intensity, mainly tubular, when compared to the streptozotocin-induced model; in addition, the morphological alterations observed by the immunohistochemical technic could be related to the renal biochemical- functional alterations / Doutorado / Medicina Interna / Doutor em Ciências Médicas

Orientadores: Ricardo de Lima Zollner, Jose Vassallo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-07-19T15:11:05Z (GMT). No. of bitstreams: 1 Zantut-Wittmann_DeniseEngelbrecht_D.pdf: 4801105 bytes, checksum: ea1e7d96c898af34bc498dbacdc9b3c8 (MD5) Previous issue date: 1994 / Resumo: O trabalho teve o intuito de estudar aspectos séricos e morfológicos na relação entre a membrana basal do folículo tiroideano e doença tiroideana auto-imune, procurando elementos que possam acrescentar subsidios para o entendimento de sua fisiopatologia. O estudo sorológico de pacientes com diversas alterações tiroideanas foi realizado através de eletroforese de transferência seguida de "immunoblot", com a finalidade de detectar anticorpos anticolágeno IV e antil~rninina, dois dos elementos principais da membrana basal. Tal procedimento possibilitou a detecção de anticorpos reativos a várias frações do colágeno IV encontrados apenas na doença de Basedow-Graves. Da mesma forma, esta especificidade pôde ser verificada para os anticorpos antilarninina existentes nos soros destes pacientes, através do reconhecimento da fração reativa de 57 kDa da estrutura da larninina. . Estes anticorpos estariam envolvidos na fisiopatologia dos mecanismos auto-imunes da doença tiroideana e não somente com o estado hipermetabólico devido à tirotoxicose, pois não ocorreram em hipertiroidismo de origem tumoral benigna. Assim, o estudo morfológico através de imuno-histoquimica, especificamente do colágeno IV e laminina J poderia elucidar alguns aspectos sobre a existência de anormalidades da membrana basal folicular na doença tiroideana auto-imune. Entretanto, não houve a demonstração de alterações importantes da membrana tanto na doença de Basedow-Graves quanto na tiroidite de Hashimoto, especialmente interrupção, inclusive em áreas de intenso infiltrado linfoplasmocitário. Foram vis11:1117.ados locais de adelgaçamento da membrana, sobretudo na doença de Graves, talvez flutos do hipermetabolismo, que liberaria colágeno IV e Jarn1n1na para a circulação, e conseqüentemente, induziria a produção de seus respectivos anticorpos.Desta forma, o anticorpo anticolágeno N poderia tratar¬se não apenas de reflexo do estado hipermetabólico, mas integrante do processo fisiopatológico da doença de Graves. De modo semelhante, nossos resultados sugerem que a tração de 57 kDa da laminina seja um provável marcador sorológico para a Doença de Basedow-Graves, contudo existe a necessidade da ampliação do estudo para que possamos relacioná-los ao estágio da doença / Abstract: The purpose of the present study is to evaluate serological and morphologic aspects concerning the basement membrane (BM) of the thyroid follicle in autoimmune thyroid disease (ATD). In this way, new elements for ~ better understanding of its pathophisiology could be suggested. In order to detect antibodies to collagen IV and laminin, two major components of the BM, serological tests of patients with the diagnosis of different thyroid diseases were performed by the transfer eletrophoresis method followed by immunoblot. Only in the Basedow-Graves' disease antibodies,' to various collagen IV fractions were detected. Also, antibodies to laminin were found in these patients' sera, detected by recognition of the 57 kDa fraction of laminin. These antibodies are probably involved in the pathogenesis of ATD and are not just consequence of hypermetabolic states due to hyperthyroidism, since no antibodies could be detected in thyroid hyperfunction caused by benign thyroid neoplasia. Production of such antibodies could be atributed to or cause BM alterations as a consequence of disturbed immunological tolerance to their components, which are otherwise recognized as self, and induction of immunologic response. If this is true, immunohistochemical staining of collagen IV an Iaminin could be useful in detecting follicIe BM disruption in A TD. Our results do not corroborate this hypothesis, since we were not able to find BM alterations in thyroid diseases, even in areas of heavy lymphoplasmatic inflamation. Finding of focal BM thinning, mainly in Graves' disease, could be preliminarly explained by hypermetabolism, delivery of collagen IV and laminin to the circulation and induction of antibody production against them. This hypothesis, however, is not corroborated by the findings in toxicadenoma, another cause of hyperthyroidism, in wich BM thinning is not present. In Hashimoto thyroiditis, in disagreement with previously reported data, no disruption, nor significant BM thinnin g were seen. The pathogenetic role of these antibodies is not yet clear, but it does not seem that they cause follicular BM damage. Further investigations are needed to characterize biologically such antibodies and to understand their relationship to follicular BM in A TD / Doutorado / Medicina Interna / Doutor em Ciências Médicas

<p>Validerat; 20151021 (global_studentproject_submitter)</p>

Animals must respond to external cues and changes in internal state by modifying their behavior. The basal ganglia are a collection of subcortical nuclei that contribute to action selection by integrating sensorimotor, limbic and reward information to control motor output. In early life, however, animals display distinct behavioral responses to risk and reward and enhanced vulnerability to neuropsychiatric disease. This arises from the postnatal maturation of brain structures such as the striatum, the main input nucleus of the basal ganglia. Here, using biochemical, electrophysiological and behavioral approaches in transgenic mice, I have explored the molecular and circuit mechanisms that control striatal maturation. In Chapter 1, I begin by reviewing the structure, physiology and function of the basal ganglia, with an emphasis on the striatum. I then describe the existing literature on the development and maturation of striatal neurons and their afferents. In Chapter 2, I review the molecular mechanisms of macroautophagy, a lysosomal degradation pathway that has recently been implicated in the regulation of neurotransmission, including its contribution to neuronal development, neurotransmitter release, and postsynaptic function. The subsequent chapters can be split into two themes. In the first, encompassing chapters 3 and 4, I characterize the postnatal maturation of striatal physiology and define circuit mechanisms that control this process. In Chapter 3, I demonstrate that dopamine (DA) neurotransmission in the striatum initiates the maturation of striatal projection neuron (SPN) intrinsic excitability. I show that DA signaling leads to the maturation of SPN excitability via increased activity of the potassium channel, Kir2. Interestingly, introduction of DA beginning in adulthood could not rescue SPN hyperexcitability while it could during the juvenile period. In Chapter 4, I characterize the maturation of cholinergic interneurons (ChIs) in the striatum and describe the biophysical mechanisms that drive increases in spontaneous activity that occur in ChIs during postnatal development. Finally, I show that the functional maturation of ChIs leads to changes in DA release during the postnatal period. The second theme includes Chapters 5 and 6, in which I explore the role of macroautophagy in striatal function and development. In chapter 5, I used biochemical approaches to show that autophagic flux is suppressed postnatally in the striatum due to increased signaling through the kinase activity of the mammalian target of rapamycin. In Chapter 6, I generated conditional knockouts of Atg7, a required macroautophagy gene, in different populations of SPNs and find that macroautophagy plays cell-type specific roles in SPN physiology. In one subtype of SPNs, macroautophagy regulates intrinsic excitability via degradation of Kir2 channels, which is the first demonstration of macroautophagic control of neuronal excitability. Finally, in Chapter 7, I conclude with a general discussion, where I highlight themes in the molecular and circuit mechanisms of striatal maturation and their implication for neurodevelopmental disease.

The striatopallidal (indirect) pathway is considered as the main modulatory locus for the basal ganglia control of motor functions. According to the classic basal ganglia model, the striatopallidal pathway inhibits motor activity mainly via its projection to globus pallidus (GPe). However, striatopallidal medium spiny neurons (MSNs) form extensive feedback and lateral inhibitory networks via their collaterals. Thus, the striatopallidal pathway may control motor activity either through its projections onto GPe or through the striatal collaterals. To further define the circuit mechanism whereby the striatopallidal pathway controls motor activity, we have developed two new optogenetic transgenic mouse lines expressing channelrhodospin-2 (ChR2) or archaerhodopsin-3 (Arch) selectively in the striatopallidal neurons under the Adora2a gene promoter. Consistent with previous optogenetic studies, we found that ChR2 activation and Arch silencing of the striatopallidal neurons in dorsolateral striatum (DLS) suppressed and increased motor activity, respectively. However, contrary to the prediction from the classical model, we found that selective activation of the striatopallidal axon projections in GPe increased locomotor activity. Thus, light stimulation of MSN cell bodies and collaterals in DLS, versus stimulation in GPe axon projections, produced opposite motor responses. This led us to reassess the function of the striatopallidal collaterals and to test the hypothesis that the profuse projections and collaterization within the striatum may contribute to striatopallidal pathway control of motor activity. We found that ChR2-mediated activation of the striatopallidal neurons in DLS induced c-Fos expression in ChR2/GFP-positive MSNs. Conversely, Arch-mediated silencing of the striatopallidal neurons induced c-Fos expression and MAPK phosphorylation in Arch/GFP-negative MSNs surrounding the Arch/GFP-positive MSNs. This c-Fos/pMAPK expression pattern in MSNs is consistent with the suppression of GABA release in GFP-positive cells, resulting in the induction of c-Fos in GFP-negative cells having collateral connections with the GFP-positive cells. Together, our findings revealed a previously unrecognized complexity and novel motor control mechanism of the striatopallidal pathway: activation of striatopallidal projections to GPe increases motor activity while activation of striatopallidal neurons and collaterals in the DLS may contribute to motor suppression. These findings call for a revisit of GPe as a potential locus for deep brain stimulation in Parkinson’s disease.

Ultrastructural observations reveal that the spermatozoid of Lycopodium obscurum is crescent shaped and contains two posteriorly directed flagella that are inserted at the front of the cell. The nucleus is broad and elongated with a narrow posterior projection or nuclear diverticulum. Spline microtubules (MTs) number 180 at their maximum and provide the framework for the cell. These MTs extend from the anterior of the locomotory apparatus and along the outermost surface of the nucleus, with a central shank of 14-17 MTs encircling the cell for at least one-third gyre beyond the nucleus. The two basal bodies are slightly staggered and positioned at the front of the cell over a highly elongated multilayered structure (MLS). The MLS extends laterally around the cell anterior and curves posteriorly over the nucleus. One large anterior mitochondrion is situated subjacent to the MLS, while numerous small mitochondria are scattered near or among the lobes of the single plastid. The plastid rests on the inner nuclear surface and contains numerous large starch grains. This cell differs from that of L. cernuum, the only other species of Lycopodium examined to date, in that it is more elongated and has an anterior-posterior orientation of the nucleus, basal bodies, MLS, and spline. Comparisons with coiled gametes of bryophytes and Selaginella suggest that some degree of coiling and cell streamlining may be ancestral in archegoniate spermatozoids.