Gamma-Amino butyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian central nervous system (CNS) and inhibits the neurotransmission by targeting the ionotropic transmembrane GABAA receptor. Modulators of the GABAA receptor targets the allosteric binding sites and modifies the GABA effect and these sites acts as superior drug targets within psychopharmacology.   Gabather AB has developed the novel compound GT-002 that is known to target the receptor and cause a behavioral effect in rodents. This project characterized the binding of the lead compound GT-002 to GABAA receptor in mammalian brain tissue by development and validation of a radioligand binding assay. In the assay a comparative evaluation was performed using the benzodiazepine (BZ) antagonist Flumazenil (FLU).   All experiments were performed using GABAA receptors originating from porcine and mouse brain tissue membrane, where no significant difference between the mammals was displayed. GT-002 binds with higher affinity and associates faster than FLU to the receptor and implies a two-binding site model. GT-002 displaced FLU and no tested competitive analytes targeting various modulatory sites of the receptor displaced GT-002, implying independent binding of GT-002 and allosterically impacts the BZ binding site.

The effects of a range of neuronal excitants were examined on the firing of central neurones of the cerebral cortex, ventrobasal thalamus, dentate gyrus and dorsal and ventral horns of the spinal cords of urethane anaesthetized rats. These responses were pharmacologically characterized on the basis of their susceptibilities to a number of antagonists and from these results, inferences were made concerning probable receptor mechanisms employed by the agonists. Throughout these experiments the technique of iontophoresis was found to be an ideal one for evaluating the effects of agonists and antagonists on single neurones. Neurones in the cortex, thalamus and Renshaw cells of the spinal cord were readily excited by acetylcholine. These responses were elicited also by both nicotinic and muscarinic cholinomimetics. Excitations produced by acetylcholine and acetyl-β-methylcholine were antagonized by atropine and those of acetylcholine and nicotinic agonists were blocked by nicotinic antagonists. The results may be interpreted as revealing a difference between excitatory cholinergic receptors in the rat and in the cat; the nature of these receptors is discussed. to The excitatory responses of ventrobasal thalamic neurones iontophoretically applied amino acids related to glutamate and aspartate could be blocked both by glutamate diethylester and α-aminoadipate. These two antagonists were found to possess different mechanisms of action however, as the ranking orders of susceptibility of the agonists differed for each antagonist. An analysis of these orders led to the proposal that more than one and possibly as many as three different receptors for the excitatory amino acids exist on central neurones. A number of additional compounds were tested for an evaluation of their antagonistic properties against the amino acid induced responses, and these results are discussed in light of possible steric requirements of the receptors. Granule cells of the dentate gyrus were excited by the amino acids and by their synaptic responses to stimulation of perforant path and commissural inputs. A differential effectiveness of glutamate diethylester and α-aminoadipate was suggestive that two distinct excitatory amino acid receptors, both of which appear to be of synaptic significance, coexist on the same neurones. The effects of octopamine were compared with those of catecholamines on neurones of the cortex and dorsal horn of the spinal cord. Both excitation and depression of neuronal firing was observed with octopamine and these responses appeared not to be correlated with those effected by the catecholamines. A further separation of the actions of octopamine and the catecholamines was evident when the amine induced responses were compared in the presence of the antagonists, propranolol and α-flupenthixol. These blocking compounds were effective in attenuating the effects of the catecholamines, but had no effect upon the octopamine induced changes in firing rate. The results suggest that receptors sensitive to octopamine and which appear to be pharmacologically distinct from those previously categorized as catecholamine receptors, may exist on central neurones of the rat. On the basis of the present findings, it was evident that when the technique of iontophoresis is combined with standard neurophysiological methods of identifying central neurones by their responses to synaptic stimulation, valuable information can be obtained concerning the nature of the synaptic transmitters employed by these cells. / Medicine, Faculty of / Cellular and Physiological Sciences, Department of / Graduate

There is considerable evidence to suggest that dopamine (DA), in addition to its role as a precursor of norepinephrine (NE) and ephinephrine, has important physiological actions in its own right. One physiological action of DA seems to be that of a neurotransmitter in the mammalian brain (Hornykiewicz, 1966). In addition, there is evidence that abnormalities of dopaminergic transmission in the central nervous system (CNS) may be of clinical importance. For example, dopaminergic over activity in the mesolimbic forebrain may be a primary feature in the etiology of schizophrenia (Meltzer and Stahl, 1976). The drugs used to treat schizophrenia act as DA antagonists in the brain (Snyder et al., 1974; Robinson et al., 1979). Drugs such as phenothiazines and butyrophenones have been shown in clinical studies to be effective in treating the fundamental symptoms of psychosis (Snyder et al., 1974). The results of animal experiments indicate that their principal mode of action is blockade of DA receptor sites in the CNS (VanRossum, 1966). However, these neuroleptics are generally nonspecific in their effects upon DA neurons and thus, cause major undesireable side effects. If new drugs could be discovered that were more structurally selective for different DA systems, then, perhaps these undesireable side effects could be eliminated. In order to develop such drugs, a closer look would have to be made at different DA systems in an attempt to demonstrate DA receptors which are topographically distinct and can thus be selectively regulated by both agonistic and antagonistic agents. The demonstration of more than one DA receptor in mammalian CNS is the subject of the research presented in this thesis.

Schizophrenia is a severe mental disorder that can manifest in various ways and is often characterized by the appearance of positive symptoms (hallucinations, delusions), negative symptoms (social and attention impairment) and cognitive dysfunction (thought disorders, memory and executive function impairments). Traditional treatment methodologies involve blocking the dopamine receptor by binding to the same site as dopamine. These treatments are largely inadequate and lead to an array of adverse side effects. Side effects include weight gain, diabetes, and movement disorders; which critically limit the therapeutic value of antipsychotic drug treatment. Limited symptom control and severe adverse effects have led to poor drug adherence and a deprived quality of life for patients suffering from schizophrenia. The complex etiology of schizophrenia combined with a lack of effective translational models and tests to represent and assess the illness have hindered drug development. Evidently, there is a strong demand for a new generation of pharmaceuticals and an improved translational pipeline for the treatment of schizophrenia. The collection of studies presented here contribute to the advancement of translational tools for drug discovery, the establishment of pre-clinical models to embody the various symptoms, and the development of a novel drug candidate for schizophrenia. Allosteric modulation of G-protein coupled receptors is evolving as a new wave of therapy with promising implications for various CNS disorders. Allosteric compounds regulate binding without blocking the receptor. PAOPA, a dopamine D2 receptor allosteric modulator, prevents and treats schizophrenia-like symptoms in pre-clinical animal models of schizophrenia with no apparent adverse effects. The studies outlined in this thesis further categorize PAOPA as a novel therapeutic candidate for schizophrenia. Moreover, the findings presented here provide further insight into the potential therapeutic mechanism of action of PAOPA and set the foundation for the development of a new generation of antipsychotic drugs. These studies constitute an innovative approach to expanding research in the field of drug development for schizophrenia. / Thesis / Doctor of Philosophy (PhD)

Dissertation (PhD)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Obsessive-compulsive disorder (OCD) is characterized by intrusive thoughts (obsessions) and repetiti ve mental acts or behaviours (compulsions) . For many years, it was considered a rather uncommon condition, caused by unconscious conflict, and somewhat resistant to treatment. In recent decades, however, it has emerged that OCD is a highly prevalent disorder, mediated by particular neuroanatomical circuits (e.g. striatal pathways) and neurochemical systems (e.g. the serotonin system), and responsive to treatment with serotonin reuptake inhibitors (SRIs) . Nevertheless, many questions remain; about the specificity of neuroanatomical findings to OCD, about the role of the multiple serotonin (5-HT) receptor subtypes (e.g. 5-HT10)' and about the appropriate pharmacotherapy for patients resistent to SRI treatment? In a series of studies, 1) the neuroanatomy of OCD was assessed by means of magnetic resonance imaging and neuropsychological testing, 2) the neurochemistry of OCD was assessed by means of functional brain imaging after administration of a 5-HT10 agonist, and 3) the pharmacotherapy of OCD was explored in a series of treatment-refractory OCD and OCD spectrum disorder patients using SRI augmentation with a dopamine blocker. Although no significant difference was found in the volume of the caudate in women with OCD and controls, there was a significant correlation between caudate volume and neuropsychological dysfunction in patients, consistent with evidence of striatal involvement in OCD. Functional imaging demonstrated behavioural heterogeneity, but brain-behaviour correlations were positive, consistent with preclinical evidence of a role for the 5-HTlD receptor in the mediation of OCD. Finally, preliminary treatment findings with dopamine blocker augmentation of a SRI were promising, consistent with preclinical understandings of the interactions between the dopamine and serotonin systems. Although oeD is a complex disorder, a number of future research avenues hold promise for providing a thorough delineation of its pathogenesis. / AFRIKAANSE OPSOMMING: Obsessief-kompulsiewe steuring (OKS) word gekenmerk deur indringende gedagtes (obsessies) en herhalende gedagtes of gedrag (kompulsies). Vir baie jare is dit beskou as 'n redelik seldsame toestand wat veroorsaak word deur onbewustelike konflik, en wat in 'n mate teen behandeling weerstandig is. Meer onlangs het dit egter na vore getree as 'n toestand wat baie dikwels voorkom, wat deur spesifieke neuroanatomiese siklusse (bv. striatale bane) en neurochemiese sisteme (bv. die serotonien-sisteem) teweeg gebring word, en wat op behandeling met serotonien heropname inhibeerders (SHIs) reageer. Nogtans is daar steeds baie vrae; oor die spesifisiteit van neuroanatomiese bevindinge vir OKS, oor die rol van die veelvuldige serotonien (5-HT) reseptor subtipes (bv. 5- HT1D), en oor die toepaslike farmakoterapie vir pasiënte wat weerstandig is vir SHI behandeling. In' n reeks van navorsingstudies, is 1.) die neuroanatomie van OKS deur middel van magnetiese resonans beelding en neurosielkundige toetse ondersoek, 2. ) die neurochemie van OKS deur middel van funksionele breinbeelding na toediening van 'n 5-HT1D agonis bepaal, en 3.) die farmakoterapie van OKS in 'n reeks van behandelingsweerstandige OKS en OKS-spektrum steuring pasiënte - waar gebruik gemaak is van SHI aanvulling met 'n dopamien-blokker - ondersoek. Alhoewel daar geen beduidende verskil in die volume van die caudata in vroue met OKS en kontroles gevind is nie, was daar 'n beduidende korrelasie tussen die caudata volume en neurosielkundige wanfunksionering in pasiënte, in ooreenstemming met striatale betrokkenheid in OKS. Funksionele beelding het positief, in demonstreer, maar ooreenstemming met brein-gedrag pre-kliniese heterogeneïteit korrelasies was in gedrag bewyse vir 'n rol vir die 5-HT1D reseptor in die bemiddeling van OKS. Ten laaste, voorlopige behandelingsbevindinge oor dopamienblokker aanvulling van 'n SHI is belowend, in ooreenstemming met v

A Doença de Parkinson (DP) é um distúrbio neurodegenerativo. Suas características e seus sintomas neuropatológicos são bem definidos, mas sua etiologia ainda continua desconhecida. A DP esporádica é caracterizada anatomo-patologicamente pela presença de Corpos de Lewy, que são agregados lipoproteicos que se encontram no interior do neurônio. A <font face=\"Symbol\">a-sinucleína é uma proteína solúvel presente nos terminais pré-sinápticos de vários sistemas de transmissão. Evidências sugerem que esta proteína é um componente fundamental dos Corpos de Lewy localizados nos neurônios dopaminérgicos do sistema nigroestrital de pacientes portadores de DP. Postula-se que a <font face=\"Symbol\">a-sinucleína possui uma função fundamental na patogênese da DP, pois pode afetar a homeostase de neurônios dopaminérgicos, levando ao aumento da dopamina no citosol e consequente estresse oxidativo. O fator de transcrição nuclear kappa B (NF-<font face=\"Symbol\">kB) participa da regulação de respostas imunes, inflamatórias e morte celular. No sistema nervoso central este fator está presente em diversos tipos de células nervosas e seu papel é paradoxal, ora apontado como neurotóxico, ora como neuroprotetor. O NF<font face=\"Symbol\">kB pode ser estimulado por vários fatores entre eles neurotransmissores (por exemplo: dopamina e glutamato), estresse e proteína <font face=\"Symbol\">b-amilóide. Neste trabalho, pretendemos estudar as modificações moleculares nas células SH-SY5Y transduzidas com a <font face=\"Symbol\">a-sinucleína na sua forma selvagem (WT), mutante (A30P) e truncada (1-120) e tratadas com meio condicionado (CM) (proveniente do tratamento da glia com LPS) ou TNF. Analisamos a modulação da atividade do NF-<font face=\"Symbol\">kB, onde observamos o aumento da atividade quando as células foram tratadas com TNF mas não com CM. Ainda, observamos que ocorre diminuição da fosforilação da proteína MAPK42/44 durante o mesmo tratamento, e que esta diminuição pode estar ligada ao aumento da morte celular. / Parkinsons Disease (PD) is a neurodegenerative disease. The characteristics and symptoms are well defined; nevertheless its etiology remains unknown. The sporadic PD is characterized by the presence of Lewy Body (aggregate of proteins) inside the neurons. Alpha-synuclein is a soluble protein present in the pre synaptic terminal of neurons. Evidences suggest that this protein is a fundamental component of Lewy bodies localized in the dopaminergic neurons of PD patients. It is already known that alpha-synuclein has a fundamental role in pathogenesis of PD, because it can affect the homeostasis of dopaminergic neurons, leading to increase of dopamine in the cytosol and consequent oxidative stress. The nuclear transcription factor kB (NF-<font face=\"Symbol\">kB) regulates the immune, inflammatory and cell death responses. In the central nervous system, this factor is present in several types of cells and its role is paradoxal, since it can be neurotoxic or can be protective. The NF<font face=\"Symbol\">kB can be stimulated by several factors, including dopamine, glutamate, stress and <font face=\"Symbol\">b-amyloid protein. In this work, we observed the molecular modification in SH-SY5Y cells transduced with alpha-synuclein (wild-type, A30P and truncated 1-120) and treated with conditioned medium (CM) (from primary culture of glia treated with LPS) or TNF. We analyzed the modulation of NF-<font face=\"Symbol\">kB activity, in which was observed that the activity was increased when the cells were treated with TNF but not with CM. Moreover, we show that there is a decrease of MAPK42/44 phosphorilation during the treatment, and this decrease is linked to the increase of cell death of these cells overexpressing alpha-synulein.

A enzima Na+, K+-ATPase é uma proteína de membrana altamente conservada em eucariotos, capaz de gerar um gradiente eletroquímico, fundamental para o balanço osmótico das células, o potencial de repouso das membranas e a propriedade excitatória das células musculares e nervosas. Além de seu papel regulatório na homeostasia iônica, desempenha um papel na transdução de sinal e na ativação de transcrição gênica, modulando na presença de ouabaína o crescimento celular, migração e morte celular programada. A Ouabaína (OUA) é um esteróide cardiotônico, produzido no córtex da adrenal e no hipotálamo. Em linhas gerais, a sinalização da Na+, K+-ATPase promovida pela OUA parece ativar vias associadas à modulação de fatores de transcrição como a via da Src, MAPK, Ca2+ e NF-<font face=\"Symbol\">kB. Evidências indicam que o NF-<font face=\"Symbol\">kB exerça algum tipo de modulação na via canônica do WNT, no entanto os mecanismos moleculares ainda são desconhecidos. A via de sinalização WNT desempenha função importante na embriogênese e na homeostase de tecidos adultos. Assim, o objetivo do presente projeto é verificar se a administração intrahipocampal de OUA é capaz de modular a atividade das vias canônicas do NF-<font face=\"Symbol\">kB e da WNT. Estas vias foram estudadas em um decurso temporal imediato (1 -2 horas) e tardio (10, 24 e 48 horas) utilizando técnicas como Western Blotting, RT-PCR e EMSA. Os resultados encontrados mostram que a OUA (10 nM) foi capaz de ativar a via de sinalização NF-<font face=\"Symbol\">kB, após 1 hora, 10, 24 e 48 horas. A OUA também foi capaz de ativar a via canônica do WNT, sendo que após 10 horas ocorreu aumento da proteína pGSK-3<font face=\"Symbol\">b, enquanto que em 24 horas, observamos aumento da translocação nuclear da <font face=\"Symbol\">b-CATENINA. Além disso, pode-se verificar aumento de BDNF ao longo de todo o decurso temporal. / The enzyme Na+,K+-ATPase is an integral membrane protein, highly conserved in eukaryotes, that establishes the electrochemical gradient across the plasma membrane, which is essential to maintain the osmotic balance of cells, the resting membrane potential and the excitatory property of nerve and muscle cells. Besides its role in ion homeostasis, several recent studies suggest that this pump may also act as a signal transducer and transcription activator involved in cell growth, differentiation and programmed cell death. Ouabain (OUA), the ligand of Na+,K+-ATPase, is a steroid derivative that is produced by the adrenal cortex and hypothalamus. After OUA binding, the Na+,K+-ATPase signaling seems to activate pathways such as Src, MAPK, NF-<font face=\"Symbol\">kB and Ca2+. Some evidences indicate a possible crosstalk between the NF-<font face=\"Symbol\">kB signaling pathway and the canonical WNT pathway, however the molecular mechanisms are still unknown. The canonical WNT play important roles during embryogenesis and in adult tissue homeostasis. The aim of this project is to verify if the intrahipocampal administration of OUA is able to modulate the activity of the canonical pathways of NF-<font face=\"Symbol\">kB and WNT. Both pathways were studied after 1 and 2 hours, and after 10, 24 and 48 hours by methods such Western blot, RT-PCR and Electrophoretic mobility shift assays. The results show that the OUA (10 nM) was able to activate the signaling pathway NF-<font face=\"Symbol\">kB after 1, 10, 24 and 48 hours. The OUA was also able to activate the canonical WNT pathway, since after 10 hours there was an increased in pGSK-3<font face=\"Symbol\">b protein, whereas in 24 hours, we observed increased nuclear translocation of <font face=\"Symbol\">b-CATENIN. Moreover, we found increased levels of BDNF throughout the time course.

Glioblastoma multiforme (GBM) is a debilitating malignant brain tumor with expected patient survival of less than a year and limited responsiveness to most treatments, often requiring biopsy for diagnosis and invasive surgery for treatment. We propose a DNA computer system, consisting of input, computation, and output components, for diagnosis and treatment. The input component will detect the presence of three GBM biomarkers: vascular endothelial growth factor (VEGF), caveolin-1α (CAV), and B2 receptors. The computation component will include indicator segments for each of these genes, and ensure that output is only released if all the biomarkers are present. The output component will consist of the therapeutic agent interleukin-12 (IL-12). This study will designate four groups of animals: untreated tumor-free (control), tumor-inoculated (RG2), treated and tumor-free (DNA), and treated and tumor-inoculated (RG2/DNA). In the RG2 and RG2/DNA groups, we will inoculate adult male Fischer rats with RG2 cells into the striatum to induce tumor growth. Rats in the DNA and RG2/DNA groups will be implanted with the DNA system at the same location via recombinant adeno- associated viral vectors. The effectiveness of the DNA system will be evaluated through tumor size measurements, collected from brain slices stained with hematoxylin and eosin, and survival curve. Additionally, IL-12 localization will confirm the release of the output component. We anticipate that the DNA treatment will result in a decrease in tumor size, leading to smaller tumor size in the RG2/DNA group versus the RG2 group. The control group is expected to survive the longest, followed by the DNA group, then the RG2/DNA group, and finally the RG2 group. In the DNA group, IL-12 is expected to stay localized to the implantation site, remaining in its unreleased stem-loop form. On the other hand, it is expected to be released and active in the RG2/DNA group. This study provides a proof of concept to demonstrate the viability and effectiveness of a DNA system using VEGF, CAV, and B2 receptors as biomarkers and IL-12 as a therapeutic output component in the RG2 model. Further research may include varying several of the parameters used in this study, including amount of RG2 administered, choice of biomarkers, quantity and choice of output component, and choice of animal model. This system provides a promising and innovative new approach that is less invasive than surgery yet is still effective in diagnosing, targeting, and treating GBM.

A enzima Na+, K+-ATPase é uma proteína de membrana altamente conservada em eucariotos, capaz de gerar um gradiente eletroquímico, fundamental para o balanço osmótico das células, o potencial de repouso das membranas e a propriedade excitatória das células musculares e nervosas. Além de seu papel regulatório na homeostasia iônica, desempenha um papel na transdução de sinal e na ativação de transcrição gênica, modulando na presença de ouabaína o crescimento celular, migração e morte celular programada. A Ouabaína (OUA) é um esteróide cardiotônico, produzido no córtex da adrenal e no hipotálamo. Em linhas gerais, a sinalização da Na+, K+-ATPase promovida pela OUA parece ativar vias associadas à modulação de fatores de transcrição como a via da Src, MAPK, Ca2+ e NF-<font face=\"Symbol\">kB. Evidências indicam que o NF-<font face=\"Symbol\">kB exerça algum tipo de modulação na via canônica do WNT, no entanto os mecanismos moleculares ainda são desconhecidos. A via de sinalização WNT desempenha função importante na embriogênese e na homeostase de tecidos adultos. Assim, o objetivo do presente projeto é verificar se a administração intrahipocampal de OUA é capaz de modular a atividade das vias canônicas do NF-<font face=\"Symbol\">kB e da WNT. Estas vias foram estudadas em um decurso temporal imediato (1 -2 horas) e tardio (10, 24 e 48 horas) utilizando técnicas como Western Blotting, RT-PCR e EMSA. Os resultados encontrados mostram que a OUA (10 nM) foi capaz de ativar a via de sinalização NF-<font face=\"Symbol\">kB, após 1 hora, 10, 24 e 48 horas. A OUA também foi capaz de ativar a via canônica do WNT, sendo que após 10 horas ocorreu aumento da proteína pGSK-3<font face=\"Symbol\">b, enquanto que em 24 horas, observamos aumento da translocação nuclear da <font face=\"Symbol\">b-CATENINA. Além disso, pode-se verificar aumento de BDNF ao longo de todo o decurso temporal. / The enzyme Na+,K+-ATPase is an integral membrane protein, highly conserved in eukaryotes, that establishes the electrochemical gradient across the plasma membrane, which is essential to maintain the osmotic balance of cells, the resting membrane potential and the excitatory property of nerve and muscle cells. Besides its role in ion homeostasis, several recent studies suggest that this pump may also act as a signal transducer and transcription activator involved in cell growth, differentiation and programmed cell death. Ouabain (OUA), the ligand of Na+,K+-ATPase, is a steroid derivative that is produced by the adrenal cortex and hypothalamus. After OUA binding, the Na+,K+-ATPase signaling seems to activate pathways such as Src, MAPK, NF-<font face=\"Symbol\">kB and Ca2+. Some evidences indicate a possible crosstalk between the NF-<font face=\"Symbol\">kB signaling pathway and the canonical WNT pathway, however the molecular mechanisms are still unknown. The canonical WNT play important roles during embryogenesis and in adult tissue homeostasis. The aim of this project is to verify if the intrahipocampal administration of OUA is able to modulate the activity of the canonical pathways of NF-<font face=\"Symbol\">kB and WNT. Both pathways were studied after 1 and 2 hours, and after 10, 24 and 48 hours by methods such Western blot, RT-PCR and Electrophoretic mobility shift assays. The results show that the OUA (10 nM) was able to activate the signaling pathway NF-<font face=\"Symbol\">kB after 1, 10, 24 and 48 hours. The OUA was also able to activate the canonical WNT pathway, since after 10 hours there was an increased in pGSK-3<font face=\"Symbol\">b protein, whereas in 24 hours, we observed increased nuclear translocation of <font face=\"Symbol\">b-CATENIN. Moreover, we found increased levels of BDNF throughout the time course.

A Doença de Parkinson (DP) é um distúrbio neurodegenerativo. Suas características e seus sintomas neuropatológicos são bem definidos, mas sua etiologia ainda continua desconhecida. A DP esporádica é caracterizada anatomo-patologicamente pela presença de Corpos de Lewy, que são agregados lipoproteicos que se encontram no interior do neurônio. A <font face=\"Symbol\">a-sinucleína é uma proteína solúvel presente nos terminais pré-sinápticos de vários sistemas de transmissão. Evidências sugerem que esta proteína é um componente fundamental dos Corpos de Lewy localizados nos neurônios dopaminérgicos do sistema nigroestrital de pacientes portadores de DP. Postula-se que a <font face=\"Symbol\">a-sinucleína possui uma função fundamental na patogênese da DP, pois pode afetar a homeostase de neurônios dopaminérgicos, levando ao aumento da dopamina no citosol e consequente estresse oxidativo. O fator de transcrição nuclear kappa B (NF-<font face=\"Symbol\">kB) participa da regulação de respostas imunes, inflamatórias e morte celular. No sistema nervoso central este fator está presente em diversos tipos de células nervosas e seu papel é paradoxal, ora apontado como neurotóxico, ora como neuroprotetor. O NF<font face=\"Symbol\">kB pode ser estimulado por vários fatores entre eles neurotransmissores (por exemplo: dopamina e glutamato), estresse e proteína <font face=\"Symbol\">b-amilóide. Neste trabalho, pretendemos estudar as modificações moleculares nas células SH-SY5Y transduzidas com a <font face=\"Symbol\">a-sinucleína na sua forma selvagem (WT), mutante (A30P) e truncada (1-120) e tratadas com meio condicionado (CM) (proveniente do tratamento da glia com LPS) ou TNF. Analisamos a modulação da atividade do NF-<font face=\"Symbol\">kB, onde observamos o aumento da atividade quando as células foram tratadas com TNF mas não com CM. Ainda, observamos que ocorre diminuição da fosforilação da proteína MAPK42/44 durante o mesmo tratamento, e que esta diminuição pode estar ligada ao aumento da morte celular. / Parkinsons Disease (PD) is a neurodegenerative disease. The characteristics and symptoms are well defined; nevertheless its etiology remains unknown. The sporadic PD is characterized by the presence of Lewy Body (aggregate of proteins) inside the neurons. Alpha-synuclein is a soluble protein present in the pre synaptic terminal of neurons. Evidences suggest that this protein is a fundamental component of Lewy bodies localized in the dopaminergic neurons of PD patients. It is already known that alpha-synuclein has a fundamental role in pathogenesis of PD, because it can affect the homeostasis of dopaminergic neurons, leading to increase of dopamine in the cytosol and consequent oxidative stress. The nuclear transcription factor kB (NF-<font face=\"Symbol\">kB) regulates the immune, inflammatory and cell death responses. In the central nervous system, this factor is present in several types of cells and its role is paradoxal, since it can be neurotoxic or can be protective. The NF<font face=\"Symbol\">kB can be stimulated by several factors, including dopamine, glutamate, stress and <font face=\"Symbol\">b-amyloid protein. In this work, we observed the molecular modification in SH-SY5Y cells transduced with alpha-synuclein (wild-type, A30P and truncated 1-120) and treated with conditioned medium (CM) (from primary culture of glia treated with LPS) or TNF. We analyzed the modulation of NF-<font face=\"Symbol\">kB activity, in which was observed that the activity was increased when the cells were treated with TNF but not with CM. Moreover, we show that there is a decrease of MAPK42/44 phosphorilation during the treatment, and this decrease is linked to the increase of cell death of these cells overexpressing alpha-synulein.