Dissertações em Neurociências e Biologia Celular (Mestrado) - PPGNBC/ICB

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2375

O Mestrado Acadêmico pertence ao Programa de Pós-Graduação em Neurociências e Biologia Celular (PPGNBC) do Instituto de Ciências Biológicas (ICB) da Universidade Federal do Pará (UFPA).

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Acesso aberto (Open Access)
Alterações morfo-funcionais em córtex isquêmico de animais tratados com transplante autólogo de células mononucleares da medula óssea
(Universidade Federal do Pará, 2015-10-08) BARBOSA JUNIOR, Mário Santos; PEREIRA JÚNIOR, Antônio; http://lattes.cnpq.br/1402289786010170; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644
Statistical data show stroke as the second leading cause of death and leading cause of disability among all other diseases in the world. The ischemic stroke (ischemic stroke) accounts for about 87% of incidence of strokes. In ischemic stroke, inflammation acts in restraint of infarction caused by ischemic stroke, and on the other hand the intensity of the inflammatory response in neurodegeneration and consequently influence the functional loss. The autologous cell therapy, mononuclear bone marrow cells, promotes modulation in neuroinflammation, being timely during an ischemic event for reduction of tissue loss and functional. In the present study, we used an experimental model of focal ischemic stroke to assess morphological and functional effects of autologous implant mononucleres bone marrow cells (CMMOs) on the morphological and functional changes related to ischemic stroke. We demonstrate in this study that the autologous BM-MNC in acute or acute and subacute periods of ischemic event, promoted neuroprotection and inflammatory modulation able to rebound in preservation and functional recovery in specific activities. We also show that the treatment enhanced in subacute period, the ischemic event, was able to promote increase in morphological and functional improvements promoted by autologous transplantation in acute period.
Acesso aberto (Open Access)
Análise cinemática do mecanismo ação-percepção em seres humanos
(Universidade Federal do Pará, 2018-08-31) SANTOS, Narrery Silva dos; GOMES, Bruno Duarte; http://lattes.cnpq.br/4932238030330851; PEREIRA JÚNIOR, Antônio; http://lattes.cnpq.br/1402289786010170
We used a manifold reaching paradigm, in two experiments, to evaluate the lateralization of motor control of arm movements. In the first experiment, we compared the kinematics of reaching movements in a manifold reaching paradigm towards a vertical bar performed with the right and left arm. Capture of kinematic data was performed with a Microsoft Kinect camera while the participants remained seated during the task. In a second experiment, participants estimated the endpoint of a third-person’s arm trajectory performing the same reaching task, but with last one-third of the movement trajectory occluded. This study included 14 individuals of both sexes with a mean age of 24.6 ± 3.9 years. The results corroborate the theory of hemispheric specialization of control of upper limb movements, with the left hemisphere being associated with precision movements and the right hemisphere with supporting movements and being more sensitive to the influence of gravity. Importantly, this difference is also reflected in the mental simulation of arm movement.
Acesso aberto (Open Access)
Análise citogenética como bioindicador para pacientes com diagnóstico sugestivo de Alzheimer
(Universidade Federal do Pará, 2013-08-02) NEGRÃO, Igor Patrick Ramos; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644; PEREIRA JÚNIOR, Antônio; http://lattes.cnpq.br/1402289786010170
Alzheimer's disease (AD) is a neurodegenerative disease that causes neuronal death and consequent progressive loss of cognitive functions, reducing the capacity for work, interfering with social relationships and behavior of the patient. Among the diseases that cause dementia, AD is the most frequent nature of the vascular a ratio of 4:1, respectively. In addition to the pharmacological therapies, diagnostic methods assist in the early identification of the disease by helping the pretreatment, thus reduced disease progression. Currently cytogenetic studies have demonstrated chromosomal abnormalities in individuals with AD and may aid in the diagnosis of disease. The aim of this study was to investigate the potential of karyotype analysis of peripheral blood lymphocytes as a diagnostic biomarker of Alzheimer's disease. For this work, we used two groups of women aged 65 or more, one group (10) suffering from AD and other normal group (10). Each subject was submitted to the socioeconomic survey, a cognitive screening test (MMSE) and the Venous blood lymphocyte culture and chromosome analysis. Our results demonstrate that the group of women with AD showed high rate of monosomy and trisomy compared to normal women. Through the study of history via questionnaire, we found the lifestyle of both groups. Compared the relationship of chromosomal abnormalities with the cognitive level of the AD group, we evidenced an inverse trend between the number of monosomy / trisomy and cognitive performance. Another aspect of our analysis was the role of each chromosome linked to AD. Chromosomes 1, 14 and 21 showed no trisomy and verify the frequency of monosomy, each chromosome has frequency below 3 % of aneuploidy, i.e., the chromosomes studied did not have a great importance in chromosomal alterations found in the study.
Acesso aberto (Open Access)
Análise comportamental e histológica de um modelo animal da doença de Parkinson em camundongos suíços
(Universidade Federal do Pará, 2011-12-29) GARCEZ, Daniela Rosa; YAMADA, Elizabeth Sumi; http://lattes.cnpq.br/7240314827308306
Parkinson’s disease (PD) is one of the most common aging-related neurodegenerative diseases, having a clinical presentation featuring classic motor symptoms related to the degeneration of dopaminergic neurons of the substantia nigra pars compacta (SNpc) and dopamine decr ease in the striatum. Animal models of PD are important tools employed by researcher aiming a better understading of pathophysiologic disease mechanisms and for evaluation of potential therapeutic interventions. Such models must mimic some aspect of the disease as for instances, the degeneration of nigral dopaminergic neurons. In this context, the PD model induced by the injection of the neurotoxina 6-hydroxydopamine (6-OHDA) has been widely established in rats but a better characterization in diferent mice strain is lacking, concerning both behavioral changes and the lesion in nigrostriatal system. Such characterization is important so that this model can be reliably used for investigations of therapeutic interventions. The goal of the present study was to improve the characterization of the unilateral 6-OHDA PD model using Swiss mice, through the evaluation of behavioral changes and the effects on the SNpc dopaminergic neurons. In this investigation we have used a single unilateral intraestriatal injection of 6-OHDA, in two different toxin concentrations: 10 µg/2µl e 20 µg/2 µl. Our results have demonstrated that both 6-OHDA concentrations used provoked severe loss of nigral dopaminergic neurons, amounting to 74,5% e 89,5% respectively. This neuronal loss was highly correlated to the apomorphine-induced rotational behavior but not to the ambulation assessed in the open field test. Therefore, intraestriatal injection of 10 µg/2µl or 20 µg/2µl of 6-OHDA, using Swiss mice, reproduce an effective unilateral 6-OHDA PD model that can be reliably employed in experiments aiming to investigate neuroprotective, cellular and/or pharmacological therapies for PD.
Acesso aberto (Open Access)
Análise quantitativa de neurônios imunomarcados para parvalbumina no hipocampo e núcleo magnocelular do istmo em Actitis macularius no período de invernada
(Universidade Federal do Pará, 2020-02) GUERREIRO, Luma Cristina Ferreira; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286; DINIZ, Daniel Guerreiro; http://lattes.cnpq.br/3269424921125406; https://orcid.org/0000-0001-7369-2165
It is already known that parvalbumin (PV) neurons have their number modified in face of social, multisensory and cognitive stimuli, both in mammals and birds. However, nothing is known about its plasticity in long-distance migratory shorebirds during wintering period. Here we investigated in four distinct temporal windows of the wintering period, the plasticity of PV neurons of two brain areas of the spotted sandpiper (Actitis macularius) which includes in its migratory journey multiple stopovers for feeding and resting. We used PV as a marker of a subpopulation of inhibitory neurons and count them in the hippocampal formation (HF) and magnocellular nucleus of tectal isthmus (IMC). Based on previous evidence that HF is involved in learning and memory and social interaction, and IMC is essential for control of head and neck and eyes movements, we tested the hypothesis that PV neurons would increase in HF and remain unchanged in IMC. For this, we used the optical fractionator to estimate cell number. Brains were processed for PV immunostaining, followed by estimates of the number of PV neurons of the areas of interest. As compared with migratory rest 1, PV neurons estimates showed significant increase in the hippocampal formation of premigration group. We suggest that parvalbuminergic neurons proliferation is part of the adaptive changes of the hippocampal circuits involved with the migratory process back to the reproductive niches in north hemisphere.
Acesso aberto (Open Access)
Aspectos morfológicos comparativos entre neurônios da camada I do córtex visual de duas espécies de roedores: Cavia porcellus e Rattus norvegicus
(Universidade Federal do Pará, 2014-08-20) MOREIRA, Thayana de Nazaré Araújo; SILVA FILHO, Manoel da; http://lattes.cnpq.br/2032152778116209
The layer I has as main characteristic the low number of neurons and a high density of nerve fibers. The morphology of neurons of layer I is still understudied, so that in studies evaluating the morphology of these neurons has not yet reached a consensus on the forms and functions of these neurons. This study evaluated the morphology of neurons in layer I of the visual cortex of two rodent species: Cavia porcellus, popularly known in Brazil as a guinea pig and Rattus norvegicus, which is the rat and the Wistar strain was used, commonly used in scientific research. The guinea pig is a widely studied animal model used in several areas of science. Although this species is well studied, works on layer I of this animal are relatively rare, especially in relation to morphology and electrophysiology of neurons in this cortical region. Research in rats on neurons of layer I are more frequent, both in relation to morphology and electrophysiology. To discriminate the potential for differences in the morphology of neurons in layer I of the visual cortex of the guinea pig and mouse, this study classified these neurons according to the trajectory of their dendrites and dendritic measures analyzed using the technique of intracellular injection of biocytin. After classification of neurons comparisons were made between the same cell types of each rodent. 35 guinea India Dunkin-Hartley variety of short-haired of both sexes aged 4-5 days of postnatal life were used. As for the rats, 30 rats of Wistar variety of both sexes aged 14 to 21 days of postnatal life were used. The animals were anesthetized and had their brains removed, separated hemispheres and sections were made in the coronal plane in the occipital region where is located the visual area of rodents. Slices were maintained in artificial cerebrospinal fluid and then brought to the microscope to inject biocytin and subsequently were fixed and treated for mounting on slides and counterstained with Nissl for better viewing. Neurons found were classified as horizontal, ascending, descending and radial. The receptive field area, total and average dendritic length, total area of the cell body, dendrites number, distance from the pia mater and distribution analysis Sholl: The following dendritic measures were analyzed. Results of the most notable were the extent of dendritic branches and the size of the cell body of neurons of layer I of the guinea pig compared to rat. This suggests that in this species, a larger number of neural microcircuits can be established, and therefore greater metabolic rate justified by the size of the cell body.
Acesso aberto (Open Access)
Ativação microglial, perda neuronal e astrocitose em um modelo experimental de epilepsia do lobo temporal
(Universidade Federal do Pará, 2011-05-12) FERREIRA, Elane de Nazaré Magno; LEAL, Walace Gomes; http://lattes.cnpq.br/2085871005197072
Epilepsy is one of the most prevalent serious chronic neurological conditions worldwide. The World Health Organization (WHO) estimates 45-50 cases in 100,000 habitants in developed countries, rising to 122 to 190, in developing countries, including Brazil. There are no risk factors in relation to gender, race or age, but it is believed that some gene mutations are associated with an increased risk to develop the disease. The pathophysiology of epilepsy involves complex factors such as loss inhibition and increased neuronal excitability in different brain regions, but mainly at the hippocampus. Mutations in ion channels and in both receptor and neurotransmitter transporters may underlie disease pathogenesis. The inflammatory response plays an important role on epilepsy pathophysiology. Recent experimental evidence suggests a major role for both microglia and astrocyte activation on the seizure exacerbation. In this dissertation, we describe the general patterns of microgial and astrocyte activation and neuronal loss in CA1, CA3, hippocampal hylus, peririnal, lateral entorrinal and motor cortices and amigdaloid complex in the first week following “Status Epilepticus” induced by pilocarpine injection. Immunohistochemistry was performed to label neurons (anti-NeuN), microglia in general (anti-Iba1), activated microglia/macrophages (anti-ED1) and astrocytes (anti-GFAP). Numbers of neurons and activated microglia were counted in the hippocampus. There was intense microglia and astrocyte activation in all motor and limbic regions studied, mainly at 3 and 7 days post SE. Minocycline treatment reduced microglia activation in the hippocampus (p<0.05), without affecting astrocytosis. There was considerable inflammation in regions outside the hippocampus with an early inflammatory response. There was no neuronal loss in the hippocampus in the first week following SE, although sporadic alterations on neuronal morphology have been observed. These results suggest that the inflammatory response is an early and generalized histopathological event in several motor and limbic structures following pilocarpine-induced SE, even in the absence of conspicuous cell loss. The patterns of microglia and astrocyte activation can be used as markers of the progressive tissue impairment in the experimental models of epilepsy.
Acesso aberto (Open Access)
Aumento da ativação neuronal e de marcação de BDNF após degradação das redes perineuronais em modelo experimental de privação sensorial
(Universidade Federal do Pará, 2016-09-23) AGUIAR, Gisele Priscila Soares de; PEREIRA JÚNIOR, Antônio; http://lattes.cnpq.br/1402289786010170; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644
The central nervous system (CNS) has the ability to processing and store information collected from the environment, and modifies and adapt under environmental stimuli diversity. However, It has low regeneration capacity after injury or neurodegenerative disease. Several works are demonstrating cellular and molecular mechanisms implicated in CNS plasticity, such as chondroitin sulfate glycosaminoglycans (GAGs-SC) important components of the extracellular matrix from nervous tissue, responsible for synaptic stabilization, toconcentrateof growth factors and ions around neurons. Removing CSPG of the nervous tissue, we can (re)opens a potential plasticity window in the CNS. The goal of our work is to evaluate the influence of removal of GAGs-SC on neuronal activity, via cFos immunolabeling, and BDNF proteins levels at the barrel cortex, under an experimental model of sensory deprivation (vibrissectomy) during critical period of plasticity. To do that, we used 18 rats (Rattus novergicus), Wistar lineage, submitted to the removal of all whiskers from their right snout (vibrissectomy) since first day of life (P0) until the end of critical period of plasticity (P30). The 40 days deprived animals received epidural polimer implant of Elvax, previously saturated with chondroitinase ABC (ChABC, to degraded the extracellular matrix) or with bovine albumin serum(BSA, control), on the barrel cortex of contralateral cerebral hemisphere to the sensory deprivation (left). The animals were perfused 10 (P50) or 20 days (P60) after Elvax implant. Our results shown that the animals submitted to the sensory deprivation, during critical period of plasticity of S1, and to GAGsSC degradation presents modification in perineuronal net (PNNs) characteristics when compared to control animals, at P50. Those animals also presents increase in cFos labeled cells (mainly at the granular layer of S1) and in BDNF labeled cells at the deprived PMBSF, both seen in 10 (P50) as 20 days (P60) after Elvax implant saturated with ChABC. In this way, we concluded that GAGs-SC removal induced local plasticity, evoking changes in cortical activity and BDNF expression at the deprived PMBSF, even 30 days after critical period of plasticity ended at S1.
Acesso aberto (Open Access)
Avaliação in vitro do efeito genotóxico e neurotóxico da rotenona em populações neuronais de encéfalo de ratos
(Universidade Federal do Pará, 2011-12-28) LIMA, Geovanny Braga; YAMADA, Elizabeth Sumi; http://lattes.cnpq.br/7240314827308306
Parkinson’s disease is a neurogenerative disease that affects dopaminergic neurons of the substantia nigra whose neurons Project to the striatum. Rotenone is a compound widely used as pesticide and which has been implicated among the environmental factors that increase the risk of developing PD. An essay that evaluate DNA damage, such as the eletroforesis comet essay, was introduced in the present work, to better understand the neurotoxic effects of the rotenone in a experimental model of PD. The comet assay was applied to neurons from mixed mesencephalic cultures exposed to different concentrations of rotenone in two different exposure times, 24 and 48 hours. The mean comet damage index showed a significant difference between the control condition and all the rotenone concentrations tested in both exposure times. However, in the comparative analysis considering time exposure for equivalent concentrations, there was significant difference only with 20 and 30 nM rotenone concentrations. This study demonstrated that, in the experimental conditions used, the comet assay detected damage to the genetic material without detectable alterations in the MTT viability test (5 nM rotenone, 24h), suggesting that genotoxic alterations may precede viability alterations in rotenone-exposed neurons. It is not possible, however, to assure that such alterations are irreversible or not.
Acesso aberto (Open Access)
Classificação de perfis de produtividade usando redes neurais artificiais a partir de registros eletroencefalográficos: uma aplicação na Mineradora Vale S.A., Complexo S11D Eliezer Batista
(Universidade Federal do Pará, 2024-01) BASTOS, Caio de Oliveira; PEREIRA JUNIOR, Antonio; http://lattes.cnpq.br/1402289786010170; https://orcid.org/0000-0002-0808-1058; GOMES, Bruno Duarte; http://lattes.cnpq.br/4932238030330851
Results and methods from neuroscience can already be applied on a routine scale. Applied neuroscience is in use, for example, to measure and study brain activity under high demand using electroencephalography (EEG). In certain work environments, human productivity is a direct function of brain activity. The intense recruitment of cognitive functions such as sustained attention and working memory influence productivity directly. The labor demands experienced by workers in mining companies are an example. This work is a part of a bigger project called “Usando Treinamento Cognitivo para o Desenvolvimento de Operadores de Alto Desempenho” from the Vale S. A. mining company and, therefore, all of the workers that participated in this study worked for that company. We used EEG to measure productivity during a task without the constraints typically found in experiments conducted in the laboratory. To this aim, we created a machine learning algorithm to analyze the resting EEG recorded before and after a 4D simulation, where mining workers (37 ± 7 years old) specialized to operate giant high-capacity shovels. The simulated task consisted of the operator using the shovel in a digging and loading routine. The task was not planned for our research. It was part of the worker’s routine training. That is, we took advantage of the workers’ training to carry out the study. Recordings were preprocessed using a band-pass filter (0.5-100 Hz) followed by filtering using ICA (Independent Component Analysis). After each operator finish the simulation, their productivity was measured by VALE S.A technical staff. The main parameter for good productivity was the amount of ore excavated. The operators were divided into groups according to ranges of productivity. The productivity was used as a label for the learning of the algorithm that consisted of an artificial neural network of the type inception. The number of neurons and layers was optimized using Bayesian optimization. The features extracted by the inception were the input to 13 classifiers. The classifier chosen for the final algorithm was the best, that is the one providing the best accuracy in the productivity classification. The training set contained 80% of the data. A hold-out validation was used to test the accuracy of the final algorithm using 20% of the data. The resulting accuracy when the operators were divided into four groups of productivity reached 91.35%. When there were only two groups of productivity the accuracy peaked at 95.05%. Our results showed that even under no laboratory constraints – during the regular training of the operators and using resting EEG – our algorithm succeed and it is ready to be used in future field operations. We have a prototype that is patentable.
Acesso aberto (Open Access)
Correlação entre medidas quantitativas de espessura retiniana, concentração de metabólitos encefálicos e funções neuropsicológicas de pacientes com transtornos neurocognitivos
(Universidade Federal do Pará, 2017-10-17) WAN-MEYL, Fabio da Silva; TEIXEIRA, Cláudio Eduardo Corrêa; http://lattes.cnpq.br/7448998858430931; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099
Currently, with the increase in life expectancy of human populations, neurodegenerative diseases, commonly occurring with the advancing age, have become a source of serious concern. Thus, research into new ways of early diagnosis of neurocognitive disorders associated with diseases such as Alzheimer's and Parkinson's, as well as the improvement of the understanding of currently available clinical neurological diagnostic methods, has been promoted throughout the world. In this sense, this work proposes to investigate the existence of possible correlations between the results of exams used in clinical neurological investigation of patients diagnosed with neurocognitive disorder associated with these important neurodegenerative diseases (Alzheimer's and Parkinson's diseases). The results show that the measurement of the thickness of the nerve fiber layer of the perimacular retina, performed by optical coherence tomography, is a parameter that may not differ significantly between groups of patients and healthy subjects. On the other hand, the measurement of the amplitude of the spectroscopic signals generated by encephalic metabolites, performed by magnetic resonance proton spectroscopy, reveals encephalic changes that vary from region to region. In addition, the neuropsychological measure of cognitive functions, performed by the automated CANTAB battery, reveals that several aspects of these functions are impaired in these patients. Finally, Principal Component Analysis shows that, considering the set of variables obtained by tomographic and neuropsychological measurements, it is possible to observe a correlation between several of these variables. Thus, it is concluded that correlating the results obtained by different approaches may add potential in the interpretation of this casuistry, which would not be possible if we consider such data in an isolated way.
Acesso aberto (Open Access)
Correlação entre parâmetros estimados pelos testes Colour Assessment and Diagnosis e Cambridge Colour Test na avaliação da discriminação de cores
(Universidade Federal do Pará, 2015-03-31) FARIAS, Letícia Miquilini de Arruda; SOUZA, Givago da Silva; http://lattes.cnpq.br/5705421011644718
The Colour Assessment and Diagnosis (CAD) and Cambridge Colour Test (CCT) tests are widely used in basic and clinic researches, because of high sensibility and specificity of your results. These tests use distinct paradigms of stimulation to estimate the color discrimination thresholds. It is not well known about the relationship of results of each paradigm in the evaluation of color discrimination in these tests. So, the present study aimed to compare the parameters of evaluation of color discrimination estimated from CAD and CCT tests. Fifty-nine trichromat subjects and thirty eight subjects with congenital dyschromatopsia (16 protans, 22 deutans) with mean age of 26,32 ±8,9 years-old were evaluated. 66 subjects were tested in CAD and CCT tests, 29 subjects in the CAD test and 2 subjects in the CCT test. The color vision phenotype of all subjects was determined through a battery of psychophysical tests and the estimative of color discrimination thresholds was evaluated by CAD and CCT tests. The data of color discrimination thresholds was fitted ellipses. The criteria analyzed to each subject were: area of the ellipses, angle of rotation of the ellipses and size of protan, deutan and tritan vectors. For each one of parameters was realized: descriptive statistic, analysis of dispersion of parameters between CAD e CCT tests and the combination of these parameters in each test, ratio between the parameters, correlation of parameters to three mathematical models and analysis of agreement. The parameters of area and size of deutan and tritan vectors of trichromat subgroup, area and size of tritan vector of protan subgroup, and size of protan and tritan vectors of deutan subgroup exhibited equivalence between the results of both tests. The parameters of area, angle of rotation and size of protan and tritan vectors showed agreement of measures between your results. Factors as the distincts localizations of neutral points of CAD and CCT tests and the spatial arrangement of the vectors in the CIE 1976 color space in the CCT test may have influenced the determination of chromatic discrimination thresholds of both tests. Despite using distinct paradigms in configuration of stimulation, the tests CAD and CCT are comparable.
Acesso aberto (Open Access)
Dispositivo para avaliação postural em ambiente tridimensional
(Universidade Federal do Pará, 2018-07-17) NASCIMENTO, Nathalya Ingrid Cardoso do; SILVA FILHO, Manoel da; http://lattes.cnpq.br/2032152778116209
The human posture can be defined as the balance between bone and muscle structures of the human body, through which it is possible to diagnose and treat various pathologies, so that science is in search of quantitative and precise methods for its analysis. A correct upright posture is considered a good health marker, making evaluation essential for a favorable therapeutic prognosis. As a result, it is necessary to develop new tools for postural evaluation with less mathematical and methodological errors to obtain accurate and reliable results for the clinic and research. The objective of this research is to present a new tool for postural evaluation, based on an electromechanical arm that allows measuring points in the three dimensional universe. The prototype was developed and improved in order to reduce errors at the time of data collection, for which a Hall effect sensor was used. The program allows to evaluate 24 relations between the points, in addition to the vertebral column analyzing the distance in millimeters and the angle in degrees between an anatomical accident and another in the anterior views, lateral right, posterior and left lateral. The initial tests were performed on the X and Y axes in an angular model, drawn at 10-degree angles and obtained low variability in their measurements, emphasizing the high accuracy of the prototype measuring system. Thus, it was possible to develop a new method of postural evaluation with low cost, high accuracy in its results for use in clinical practice, research and later insertion in the single health system.
Acesso aberto (Open Access)
Efeito antineoplásico do composto 4,2´,3´,4´-tetrametoxi chalcona em linhagem de neuroblastoma B103 de rato
(Universidade Federal do Pará, 2014-03-28) COSTA, José Elierson Barros; SILVA, Anderson Manoel Herculano Oliveira da; http://lattes.cnpq.br/8407177208423247
Neuroblastoma is the most frequently diagnosed malignancy in childhood. The term is commonly used to refer to a wide variety of neuroblastic tumors, including neuroblastomas, ganglioneuromas and ganglioneuroblastomas. Estimates show that 8 million children under 15 years of age per year are affected by this cancer, where 80% of cases are affected in up to 4 years of age, the tumor is malignant cells derived from embryonic arising from primary neuronal cells, since nodes adrenal medulla and sympathetic to other points. In this study, we assessed the cytotoxic potential of the compound 4,2 ', 3', 4'- tetrametoxchalcone in vitro model B103 rat neuroblastoma. Drug stock solutions were prepared at 50mM in dimethylsulphoxide (DMSO) and stored at - 20 ° C for the preparation of new concentrations (150μM, 100 mM, 75 mM and 50 mM). Cell viability was assayed from culture of glial cells from rat cortex. Cell migration assays and colony formation were also conducted. For statistical analysis, analysis of variance criterion (ANOVA) followed by Tukey test using the BioEstat 5.0 program was conducted. In the evaluation of cytotoxic effect of chalcones, it was observed that treatment with the compound 4,2’,3’,4’- tetrametoxchalcone showed no cytotoxic effect against normal cells of rat cortex for the concentrations tested, whereas in cell cultures neuroblastoma B103 was shown that the drug promotes cell death significantly.
Acesso aberto (Open Access)
Efeito combinado do exercício físico e da degradação da matriz extracelular na plasticidade do córtex cerebral após isquemia
(Universidade Federal do Pará, 2014-04-14) CASTRO, Ketlin Jaquelline Santana de; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644; PEREIRA JÚNIOR, Antônio; http://lattes.cnpq.br/1402289786010170
Cerebrovascular diseases are major cause of neurological disability and death in Brazil, and more than 80% of them are caused by ischemic stroke. The survivors subsist with a variety of sensory, cognitive and motor deficits. Therefore, it becomes necessary to develop therapeutic strategies to promote functional recovery in this patients. After ischemia, there is an increase in the inhibitory molecules expression as proteoglycans of chondroitin sulfate (CSPGs) presents in the extracellular matrix of the nervous tissue. The removal of these molecules, as well as physical exercise, have been used as strategy to induce another window of brain plasticity and improve functional recovery. In this work, we running experimental ischemic injury on sensorimotor areas forepaw representation (S1/M1) and tested associations between removal of CSPGs and physical exercise in n=16 Wistar rats (Rattus norvegicus). To delivery drugs to the forepaw representation in the cerebral cortex, we used a biomembrane previously ChABC-saturated or BSA-saturated and all animals had 21 days of survival divided in: Control group or BSA; Exercise group; ChABC group; and ChABC + Exercise group. The lesion area was no different across groups (control: 0,48±0,12; exercise: 0,46±0,05; ChABC: 0,50±0,18; ChABC+exercise: 0,50±0,18; ANOVA and Tukey post-test). Animals that were subjected to CSPGs enzymatic removal showed immunostaining for anti-chondroitin-4-sulphate (C4S) antibody in lesion area at the end of survival, with no evidence of CSPGs degradation in Control and Exercise groups. We evaluated the functional recovery of affected paw running vertical exploration test and ladder rung walking test. The vertical exploration test showed ischemic injury did not cause extensive functional loss, not changing exploratory behavior, or the use frequency of the affected forepaw after injury (Control group: baseline (0,03±0,10), 3d (0,29±0,17), 7d (0,30±0,10), 14d (0,29±0,16) e 21d (0,27±0,13) days after injury; Exercise group: baseline (0,30±0,12), 3d (0,32±0,24), 7d (0,19±0,37), 14d (0,31±0,10) e 21d (0,32±0,09) days after injury; ChABC group: baseline (0,34±0,07), 3d (0,20±0,11), 7d (0,23±0,07), 14d (0,33±0,14) e 21d (0,39±0,16) after injury; ChABC + Exercício group: baseline (0,34±0,04), 3d (0,20±0,09), 7d (0,26±0,04), 14d (0,18±0,08) e 21d (0,27±0,04) after injury (ANOVA and Tukey post-test). The group that only had removing CSPGs presented a better performance on Ladder rung walking test but at the end of the 21-day survival, the control groups and ChABC + Exercise reached a spontaneous recovery (equivalent to pre-injury test) reaching the ChABC group. The group treated with Exercise did not achieve the spontaneous recovery showing a motor performance significantly lower than other groups at all times of reevaluation (baseline: 8,40±0,28; 3d: 4,30±0,48; 7d: 4,75±0,50; 14d 5,35±0,41; 21d: 5,05±0,67; ANOVA and Tukey post-test). We conclude that the removal of CSPGs early improves motor performance in the affected forepaw after stroke on sensoriomotor cortex but associate with specific physical exercise doesn’t improve functional recovery.
Acesso aberto (Open Access)
Efeito do ambiente sobre o período crítico de plasticidade do córtex pré-frontal de ratos
(Universidade Federal do Pará, 2012-11-19) FOLHA, Otavio Augusto de Araujo Costa; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644; PEREIRA JÚNIOR, Antônio; http://lattes.cnpq.br/1402289786010170
The critical period of plasticity is a period of postnatal brain development in which neural circuits are most susceptible to environmental influence. The critical period of plasticity of the human prefrontal cortex, which is responsible for executive functions, extends from birth to the end of adolescence and early adulthood. The critical period is defined, among other factors, by the maturation of perineuronal nets, a specialized structure of the extracellular matrix, which surrounds cell bodies and proximal dendrites of inhibitory interneurons. The aim of the present work was to ascertain the effects of environmental, through different adolescence phases, on the morphofunctional structure of the prefrontal cortex of rats and the spatial and temporal distribution of perineuronal nets. Executive functions were also evaluated by testing working memory capacity and behavioral inhibition. We observed that the chronic exposure to unpredictable stressors cause changes the critical period of plasticity in the prefrontal cortex and thereby influence the maturation of executive functions. We also observed that chronic stress induces changes in the spatial and temporal expression of perineuronal nets in the prefrontal cortex. More specifically, it induces the early maturation of these structures in adolescent rat brain. These results indicate the vulnerability of the adolescent brain to the negative effects of chronic stressors present in the environment.
Acesso aberto (Open Access)
Efeitos anti-inflamatórios e neuroprotetores do extrato de cipó-pucá (Cissus verticillata) após isquemia focal induzida por microinjeções de endotelina-1 (ET-1) no córtex motor de ratos adultos
(Universidade Federal do Pará, 2018-12-19) COSTA, Jonabeto Vasconcelos; LEAL, Walace Gomes; http://lattes.cnpq.br/2085871005197072
The inflammatory response may exacerbate the damaging process after acute neural disorders such as in stroke. Alternatives to obtain a decrease in the inflammatory response in the encephalic cell accident have been widely studied with the use of herbal compounds, in this hypothesis the pucá cucó (Cissus verticillata), an Amazonian medicinal plant popularly used as anti-inflammatory and antihyperglycemic used by folk medicine in the treatment of acute inflammatory diseases. However, there are no investigations into the possible anti-inflammatory and neuroprotective effects of plant extract in experimental models of acute neural disorders. In this study, we investigated the anti-inflammatory and neuroprotective effects of plant extract by supercritical extraction in adult rats submitted to acute injury induced by endothelin-1 (ET-1) in the motor cortex. Two experimental groups were delineated: the first with animals of the control group with a survival time of twenty-four hours and seven days (Group N = 3 for each survival time), submitted to focal ischemia with ET-1, but injected 5% tween intraperitoneal (ip), and the second group of animals treated with doses of 100 mg / kg (ip) of plant extract after surgery with the same survival times (Group N = 5 for each survival time). Then perfused twenty four hours and seven days after induction of ischemic injury. General histopathological analysis was performed in sections stained by cresyl violet and hematoxylin. Neutrophils and macrophages were identified by immunohistochemistry with specific antibodies (anti-MBS1 and IBA-1, respectively), astrocytes labeled with anti-GFAP antibody. Activated microglia/ macrophages and neuronal bodies were counted in the mentioned experimental groups and the astrocyte activity after the lesion was evaluated. Treatment with Cissus verticillata extract induced anti-inflammatory and neuroprotective effects in treated animals, as well as decreased tissue cavitation, astrocyte activation at the center of the lesion and decreased infiltration of polymorphonuclear and/or microglia/ macrophage inflammatory cells.
Acesso aberto (Open Access)
Efeitos da adaptação ao flicker de luminância sobre o potencial cortical provocado visual
(Universidade Federal do Pará, 2015-08-20) LOUREIRO, Terezinha Medeiros Gonçalves de; SOUZA, Givago da Silva; http://lattes.cnpq.br/5705421011644718
Visual Evoked Potential (VEP) has been a useful method to evaluate spatial vision in humans. Sustained observation of a visual stimulus produces several changes in neural responses at different processing levels in visual system. Previous studies has elucidated how primary visual cortex processing spatial information. Many others studies has also suggested about the contribution of parallel pathways M and P activation on the visual cortical responses evoked by a stimuli that excite only one of these pathways. Cortical excitation through a kind of stimulus that promotes one or both preferential adaptation could be a valuable approach to study activity from M and P pathways interactions on the visual responses. The purpose of this study is to evaluate the effects of luminance flicker adaptation on cortical responses elicited under favorable conditions of joint or differential M and P pathways activation, leading to an increase or decrease cortical responses. Eight subjects (20.25 ± 1.5) with normal vision acuity or corrected to 20/20 were tested. VEPs were recorded under three conditions of visual stimulation with no adaptation: sinusoidal gratings at 0.4, 2 and 10cpd presented at 1 Hz pattern-reversal stimulus (test stimuli). Other conditions was elicited by two-dimensional Gaussian mask adaptation stimulus with luminance variation in time domain (flicker) presented at 5 Hz, 10 Hz and 30 Hz temporal modulation. The experiment consisted on VEPs records above occipital scalp elicited by 8 seconds of adaptation stimulus followed by 2 seconds test stimuli. Cortical responses were evaluated in the time and temporal frequencies domain. In the time domain were measured latency and the P1 component amplitude (peak-line), while in the temporal frequency domain were evaluated amplitudes of alpha, beta and gamma frequency bands present in the in the records. VEPs elicited by the test stimuli were compared between flicker adaptation and no adaptation conditions. Main findings consisted on flicker adaptation that occurred differently at spatial frequencies domain. Results showed P1 component in all stimulation conditions and flicker adaptation at lower spatial frequency (0.4 cpd) in all time conditions. It has also showed a reduction at alpha band energy and an increase in the gamma band at same condition. This study concluded that flicker adaptation led to VEP amplitude decreased due to loss of alpha oscillations energy and gamma band energy increased at 0.4 cpd, and it represented a modification on the balance between M and P visual pathways.
Acesso aberto (Open Access)
Efeitos da estimulação multissensorial e cognitiva sobre o declínio cognitivo senil agravado pelo ambiente empobrecido das instituições de longa permanência
(Universidade Federal do Pará, 2012-08-27) OLIVEIRA, Thaís Cristina Galdino de; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286; DINIZ, Domingos Luiz Wanderley Picanço; http://lattes.cnpq.br/9601463988942971
The aim of the present report is to investigate possible impacts of cognitive and multisensory stimulation on the performances of institutionalized and community people in the mini-mental state examination (MMSE) and in language tests. Subjects were divided in two groups paired by years of school and age: 1) institutionalized (n = 25, 76.0 ± 6.9 years old) which inhabit in long-stay institutions and 2) non-institutionalized (n = 17, 74.2 ± 4.0 years old) which inhabit in the community with their families. MMSE was applied to select cognitively healthy volunteers which were subsequently submitted to the stimulation and neuropsychological and language assessments. MMSE and specific language tests, including Boston naming, semantic (VSF) and phonological (PSF) verbal fluencies, Montreal Communication Evaluation Battery (MAC) and the Boston cookie theft picture description task were done. The multisensory and cognitive intervention was applied in groups of 10 volunteers submitted to a series of stimulation sessions twice a week, over six months in a total of 48 sessions. Sessions were based on language and memory exercises, visual, olfactory and auditory stimulus, as well as ludic activities including music, sing and dance. Both groups were assessed at the beginning (before interventions), in the middle (after 24 sessions) and at the end (after 48 sessions) of intervention. As compared to the non-institutionalized (community) group, the institutionalized one showed lower performances in all tasks in all time windows. Each patient was compared with himself using a contrast index (C) that was designed to be able to express performances of all tests in a single (0 -1) scale of cognitive performances. The contrast index was estimated as follow: (C = (D – A) / (D + A), where D corresponds to the scores before stimulation and A after stimulation). All patients improve their performances after intervention and the impact was significantly higher in the institutionalized group. We suggest that the impoverished environment where institutionalized people live is contributing to the lower cognitive scores observed at the first assessment and by the higher impact of the stimulation program in this group. As compared to the classic MMSE neuropsychological test, language tests seem to be much significantly more sensitive to detect early changes in the cognitive status. Taken together the results may have implications for public health policies dedicated to the aged population.
Acesso aberto (Open Access)
Efeitos da terapia motora baseada em movimentos de dança nas funções da teoria da mente e do ritmo Mu de pessoas com doença de Parkinson
(Universidade Federal do Pará, 2023-08) VILHALVA, Jade Thalia Rodrigues; KREJCOVA, Lane Viana; http://lattes.cnpq.br/2604693973864638; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644; https://orcid.org/0000-0003-3794-4710
Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects brain regions whose neural circuitry is responsible for controlling voluntary movements. In addition to motor symptoms, PD patients have non-motor symptoms that drastically affect their quality of life. These include cognitive alterations, among which deficits in working memory, deficits in executive functions and in the ability to deduce the mental states of others (Theory of Mind: ToM) stand out, and may also be related to the functions of mirror neurons (MN). The MN are neurons activated when a person performs or observes a given action, thus performing “internal” simulation of the observed acts, a necessary process for the ability to recognize emotions and intentions in the ToM. Their activity is influenced by prior training of observed motor actions and can be recorded using electroencephalography (EEG) through changes in the Mu band wave amplitudes (alpha 1 waves) detected when an individual observes the actions of another person. The present work investigated the effects of motor therapy on electroencephalographic activity and its correlations with MT functions in patients affected by PD. For this purpose, electroencephalographic evaluations were performed to investigate desynchronization patterns characteristic of mirror neuron activity, in addition to the Reading the Mind in the Eyes (RME) and Faux Pas Recognition (FPR) tests. We evaluated patients diagnosed with PD (n=09), under pharmacological regimen, Hoehn and Yahr 2-4, of both sexes and with mean age of 62.9 ± 7.1 years and mean of 5.8 ± 1.3 years of diagnosis , in time windows before joining the project after twelve months of participation in 2 weekly sessions of motor therapy in dance. Tabulated data were analyzed using Student's t-test. No significant differences were observed in the evaluation parameters of the FPR test in the Test and Retest temporal windows, whereas in the RMT test the average score obtained by the participants in the Test was 9.7 points, while in the Retest the average was 11.3 points with observed significance (p=0.0148), whereas electroencephalographic statistical analysis (TRPs) showed significant results in the level of desynchronization of alpha 1 waves (p=0.014 and p=0.010) during specific electrophysiological evaluation. The data showed that although the individuals did not show improvement in performance in most components of the analyzed TM tests, the electrophysiological results indicate alteration of specific cortical activity related to the activation of the mirror neuron system, influenced by motor therapy in dance, which may configure then, as an adjuvant therapeutic option in the management of motor and non-motor symptoms of PD.