Navegando por CNPq "CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA::FISIOLOGIA GERAL::NEUROFISIOLOGIA"

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Alteração diferencial nos astrócitos radiais do hipocampo e neurogênese em aves marinhas com rotas migratórias constantes
(Universidade Federal do Pará, 2019-08-17) LIMA, Camila Mendes de; MAGALHÃES, Nara Gyzely de Morais; http://lattes.cnpq.br/2519507561210918; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286; https://orcid.org/0000-0001-6611-6880
Little is known about environmental influences on radial glia–like α cells (radial astrocytes) and their relation to neurogenesis. Because radial glia is involved in adult neurogenesis and astrogenesis, we investigated this association in two migratory shorebird species that complete their autumnal migration using contrasting strategies. Before their flights to South America, the birds stop over at the Bay of Fundy in Canada. From there, the semipalmated sandpiper (Calidris pusilla) crosses the Atlantic Ocean in a non-stop 5-day flight, whereas the semipalmated plover (Charadrius semipalmatus) flies primarily overland with stopovers for rest and feeding. Using hierarchical cluster and discriminant analysis of morphometric features to classify three-dimensionally (3D) reconstructed cells, we identified two morphotypes of radial glia, designated as Type I and Type II. The migratory process affected these cells differentially, with more intense morphological changes in Type I than in Type II morphotypes in both species. We also compared the number of doublecortin (DCX)-immunolabeled neurons with morphometric features of radial glial–like α cells in the hippocampal V region between C. pusilla and C. semipalmatus before and after autumn migration. Compared with migrating birds, the convex hull surface of radial glial–like α cells of wintering birds significantly increased in both C. semipalmatus and C. pusilla. This increase correlated with an increase of the total number of DCX-immunolabeled neurons in wintering birds. The decreased radial astrocyte morphological complexity in the semipalmated sandpiper and its increase in the semipalmated plover, a species that probably relies more on visuospatial information for navigation, may be significant, despite phylogenetic and other differences between these taxa. The migratory flight of the semipalmated plover, with stopovers for feeding and rest, versus the non-stop flight of the semipalmated sandpiper may differentially affect radial astrocyte morphology and neurogenesis.
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 comparativa dos padrões neurodegenerativos da substância cinzenta em diferentes áreas corticais de ratos adultos submetidos à lesão isquêmica focal
(Universidade Federal do Pará, 2012-09-27) SANTOS, Enio Maurício Nery dos; LEAL, Walace Gomes; http://lattes.cnpq.br/2085871005197072
Stroke can occur in any region of the central nervous system (CNS). The cerebral cortex is one of the most often affected areaby this acute neural disorder, but there are no studies that have compared the damaging pattern in different cortical regions after acomparable focal ischemia. The aim of this investigation was to evaluate the degenerative pattern of different cortical areas after focal ischemic injury. Focal ischemia was induced by stereotaxic microinjections of endothelin-1 (ET-1) into the somatosensory, motor and association cortices of adult rats (N = 45). The control animals were injected with the same volume of sterile saline (N = 27). The animals were perfused 1, 3 and 7 days after the ischemic event. The brain was removed, postfixed, cryoprotected, and sectioned in a cryostat. The general histopathology was evaluated in 50μm sections stained with cresyl violet. 20μm sections were submitted to immunohistochemistry for astrocytes (anti-GFAP), activated microglia / macrophages (anti-ED1) and overall microglial population (anti-Iba1). The damaging patterns werequalitatively evaluated under optical microscopy and quantitatively by counting the number of cells in the ipsilateral and contralateral sides to injury.Descriptive statistics and comparisons within and between groups were performed using analysis of variance with Tukey post-hoc test. Conspicuous ischemic tissue loss, microglial activation and astrocytosis were observed mainly 3 and 7 days after ischemia, which was not observed in control animals. The tissue loss and activation of glial cells were more intense in the somatosensory cortex, followed by the motor cortex. The association cortex displayed less damage compared to other cortical areas, which was confirmed by quantitative analysis. The results suggest that an ischemic lesion of the same intensity induces a differential pattern of tissue loss and neuroinflammation, depending on the cortical area, and that the primary sensory and motor areas are more susceptible to ischemia than association areas.
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)
Atividade antiproliferativa e antineoplásica de flavonóides da espécie Brosimum acutifolium em modelo de glioblastoma in vitro
(Universidade Federal do Pará, 2013-05-24) MAUÉS, Luis Antônio Loureiro; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978
Among the tumors that affect the nervous system, glioblastoma multiforme (GBM) is notable by its high degree of aggressiveness and poor prognosis, with an average survival of 15 months from diagnosis. The present study aimed to investigate the antiproliferative and antineoplastic activity of four flavonoids isolated from species Brosimum acutifolium (Huber). two flavans: 4'-hydroxy-7,8-(2",2"-dimethylpyran)-flavan (BAS-1) and 7,4'-dihydroxy-8-(3,3-dimethylallyl)-flavan (BAS-4), and two chalcones: 4,2'-dihydroxy-3',4'-(2",2"-dimetilpirano)-chalcone (BAS-6) and 4,2',4'-trihydroxy-3'-(3,3-dimethylallyl)-chalcone (BAS-7), tested on rat C6 glioblastoma in vitro. Our results showed good cytotoxic activity for flavans (BAS-1, -4) and the chalcone BAS-7, with IC50 less than 100 μM in the MTT viability test, since the chalcone BAS-6, showed no cytotoxicity at the concentrations tested. These flavonoids showed less cytotoxity for non-neoplastic cell (glia), with higher degree of security for the BAS and BAS-4-7, once showed lower cytotoxic effect on non-neoplastic cell, and less hemolytic. Analysis of cell migration showed that treatment with BAS-1; -4 and -7 at low concentrations was effective in promoting the inhibition of cell migration. These three flavonoids were also very promising in inhibiting colony formation and growth, and promote cell cycle arrest with a substantial increase in population SubG0 for treatment with BAS-1 and -4 with 100 μM. The flavans BAS-1 and -4 also showed increased ability to promote losing in the integrity of the mitochondrial membrane potential (ΔΨm) and increased for staining with Annexin V, indicating that these drugs cause death by apoptosis. However the analysis by electron microscopy showed markedly the presence of autophagic vacuoles in the treatment with BAS-4 suggesting that the process of cell death occurs by apoptosis as well as autophagy. Based on these results it can be concluded that the flavonoids BAS-1, -4, and -7 have potential as an anticancer agent in the therapy of GBM and BAS-4 is the most promising of all.
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)
Caracterização da injúria no córtex motor de ratos em um modelo de exposição crônica ao metilmercúrio (MeHg)
(Universidade Federal do Pará, 2016-12-21) SANTANA, Luana de Nazaré da Silva; LIMA, Rafael Rodrigues; http://lattes.cnpq.br/3512648574555468
The mercury is an environmental contaminant which poses a great risk to human health. Exposure to this toxic metal occurs mainly through a diet contaminated by methylmercury (MeHg) in low concentrations and over a long period of time. Thus, in this study we propose an assessment of the effects of MeHg on the motor cortex in an animal model of chronic exposure and low dose, similar to dietary exposure in areas of high environmental toxicity of mercury. Adult rats were exposed to MeHg for 60 days with a dose of 0.04 mg/kg/day, while the control group received only the vehicle. After this period, they were subjected to behavioral testing in order to evaluate the motor performance after mercury exposure, and then sacrificed and evaluated for oxidative biochemical parameters (change in the concentration of nitrite - NO Lipid Peroxidation - LPO and Antioxidant Capacity Total) as well as evaluation of total deposits of mercury in the motor cortex and changes in cell density of neurons and astrocytes. Data were tabulated and statistically analyzed by Student's t-test (p <0.05). It was possible to observe total mercury deposits in the motor cortex, and deficits in motor parameters, with a reduction in the overall locomotion, on balance and increase in the number of failure, coupled with a significant increase in the levels of NO and LPO and decreased ability antioxidant full of animals exposed, reducing the population of astrocytes and neurons compared to control animals these findings suggest that exposure of adult animals to MeHg, even at low dose and chronically, causes changes in the motor cortex with damage to their functions.
Acesso aberto (Open Access)
Caracterização dos efeitos comportamentais, teciduais e bioquímicos da administração intermitente e episódica de EtOH em ratas da adolescência à fase adulta
(Universidade Federal do Pará, 2016-10-18) FERNANDES, Luanna de Melo Pereira; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
The consumption of ethanol (EtOH) is enhanced particularly in adolescent female pubic. The EtOH intake and intermittent episodic own consumption rate around 3 times per week. The toxic effects of this kind of consumption is especially dangerous over the continuous consumption of EtOH followed due to the high dietary intakes of abstinence, causing major changes in the central nervous system (CNS) maturing in a short time consumption. Considering the epidemiological relevance and the harmful effects of EtOH on the oxidative balance, hormone production and neurotrophin CNS maturing, the aim of this study was to investigate the behavioural, tissue and biochemical responses derived from intermittent and episodic consumption of EtOH in rats in phase from adolescence to adulthood. Wistar female adolescents (n = 80) received by gavage, distilled water or EtOH (3 g/kg/day) for 3 consecutive days per week. The animals were assessed seven and a half hours after the last administration day 1, 4 and 8 weeks of episodes of binge drinking (37, 58 and 86 DPN, respectively), besides, a period of 14 days of abstinence was added after BD 8 (100 DPN) to evaluate the ability to reverse the CNS damage generated on it. The battery of behavioural tests consisted of spontaneous locomotor activity, object recognition, elevated plus maze, test pole, walking beam and rotarod. The animals were sacrificed and blood samples collected for evaluation of corticosterone levels of malondialdehyde, catalase activity, the activity of superoxide dismutase and glutathione content. Therefore, the hippocampus was dissected to quantify the immunocontent BDNF. The administration of EtOH reached average peak blood concentration of 197.4 mg / dL and the period of 7.5 hours after the last administration EtOH in acute binge blood concentration was 0.7 mg / dL. Thus, the animals underwent behavioural tests post-consumer EtOH, not under the drug effect. Consumption of EtOH in binge did not affect weight gain of adolescent animals into adulthood, however, reduced the exploratory locomotor activity, impaired motor coordination, balance and motor learning associated with bradykinesia, as well as loss in the mnemonic process and increased anxiety-like behaviour. These losses were accompanied by hormonal elevation of corticosterone, reduced hippocampal BDNF levels and systemic imbalance in the oxidative balance. Thus, it was possible to identify that the damage found on the similar behaviour to anxiety, short-term memory, bradykinesia and spontaneous locomotor activity appeared from EtOH post-consumption for three consecutive days, however, they showed no recovery or worsening of damage after repeated episodes. In contrast, there was recovery of short-term memory in object recognition task associated with the return of normal levels of BDNF in adulthood. Moreover, it showed worsening in motor learning in young adult phase followed by gradual and partial recovery after prolonged period of drug withdrawal, yet the loss of motor coordination and balance remained in adulthood.
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)
Desenvolvimento de aplicativo para realização do finger tapping test e a influência do sexo e da dominância manual no desempenho do finger tapping test baseado em smartphone
(Universidade Federal do Pará, 2023-11) BRITO, Felipe André da Costa; SOUZA, Givago da Silva; http://lattes.cnpq.br/5705421011644718; https://orcid.org/0000-0002-4525-3971
The Finger Tapping Test (FTT) is a classical neuropsychological test that assesses motor functioning, and recently it has been employed using smartphones. For classical protocols, it has been observed that sex and handedness influence the performance during the test. By assessing the influence of sex and handedness on the test, it is possible to adjust the performance measurements to ensure the validity of test results and avoid sex- and handedness-related bias. The present study aimed to evaluate the influence of sex and handedness on smartphone-based FTT performance. We developed an Android application for the FTT and recruited 40 males and 40 females to carry out three spatial designs on it (protocols I, II, and III). Participants’ performance was measured using the global, temporal, and spatial parameters of the FTT. We observed that for the performance in protocol I, handedness had a significant influence on global and temporal variables, while the interaction between handedness and sex had a greater influence on spatial variables. For protocols II and III, we observed that handedness had a significant influence on global, temporal, and spatial variables compared to the other factors. We concluded that the smartphone-based test is partly influenced by handedness and sex, and these factors should be considered during the evaluation of the smartphone-based FTT.
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.