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Estudo da distribuição da proteína S100b em encéfalo de ratos.; Distribution of the S100b protein specific in brain of the rats.

Campos, Leila Maria Guissoni
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/12/2007 PT
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A proteína S100b no cérebro é produzida e secretada pela célula da glia astrócito, e exerce de acordo com sua quantidade extracelular, ação trófica ou tóxica sobre os neurônios. Investigamos a distribuição da proteína S100b, no animal em condição basal, realizando o mapeamento em diferentes áreas do encéfalo, com a técnica imuno-histoquímica, explorando a hipótese do aparecimento de S100b em áreas encefálicas preferenciais. A distribuição da proteína foi analisada pela técnica do imuno-histoquímica, com utilização de anticorpo anti-S100 (b subunidade). O mapeamento da proteína S100b ao longo do eixo AP, permitiu observar marcação de elementos gliais distribuídos pelo telencéfalo, diencéfalo, e tronco encefálico, onde a proteína apresentou-se preferencialmente distribuída, na comparação dos animais. Nossos resultados sugerem que a proteína pode estar relacionada ao fato dessa distribuição ser conservada como padrão dentro da espécie.; S100b protein is expressed primarily by astroglia in the brain, and practice functional implication of S100b secretion by astrocytes into the extracellular space is scant but there is substantial evidence that secreted glial S100b exerts trophic or toxic effects depending on its concentration. We provide here a detailed description of the distribution of the calcium-binding protein S100b in and glial elements in the encefalo of rats. The distribution of S100-like immunoreactivity was analyzed by antisera: monoclonal...

Sinalização inflamatória e a modulação da expressão de genes induzida pela ação da ouabaína nas isoformas a1, a2 - Na+, K+- ATPase em células da glia.; The influence of Na,K-ATPase isoforms in ouabain signaling cascade against LPS induced NF-kB activation in glial cells.

Kinoshita, Paula Fernanda
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/09/2013 PT
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Na,K-ATPase é uma proteína de membrana que tem como função manter o equilíbrio osmótico nas células pela hidrólise de ATP. A ouabaína (OUA) se liga a Na,K-ATPase e é capaz de ativar cascatas de sinalização. As subunidades a da Na,K-ATPase possuem 4 isoformas que são distribuídas de forma diferenciada nos tecidos. As células da glia são importantes na resposta contra lesões no cérebro e também controlam a inflamação. Dados na literatura mostram que a OUA tem efeito protetor em alguns tipos de dano. O objetivo do estudo é avaliar a função da isoforma a2 na cultura de células da glia em resposta à OUA e ao LPS. Nós investigamos a ação da OUA em diversas concentrações e LPS (1g/mL) na viabilidade celular (LDH) e proliferação celular (MTT). O LPS foi utilizado como modelo de inflamação e uma das perguntas era se o tratamento prévio com OUA, seria capaz de reverter a ativação do fator de transcrição NF-kB que está envolvido com inflamação. O pré-tratamento com OUA diminuiu a ativação do NF-kB induzida pelo LPS. Após, nós silenciamos a isoforma a2 das células da glia com RNAi. Os nossos dados mostram que o pré-tratamento com OUA reverte o efeito na ativação do NF-kB causado pelo LPS. Provavelmente...

Efeitos da administração aguda de glicose após atividade física sobre o comportamento relacionado à ansiedade, memória e neuroplasticidade; Not informed by the author

Shimizu, William Akira Lima
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 02/02/2015 PT
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O estímulo pela atividade física pode mediar a ação do IGF-1 sobre a indução à neuroplasticidade, modular o neurometabolismo e influenciar a memória e a ansiedade. Entretanto, a atividade física também pode induzir à hipoglicemia, condição que pode ser revertida com a administração de rápida fonte de glicose provinda da alimentação. Assim como a atividade física, a dieta exerce forte influência nos processos moleculares, celulares e comportamentais e estudos analisando o efeito exclusivo de dietas ricas em açúcar revelam prejuízos sobre a memória e favorecimento à ansiedade. Portanto, analisar os efeitos moleculares e comportamentais num protocolo que contemple atividade física e dieta não exclusiva de xarope de milho podem corroborar ou discordar das pesquisas que analisam os mecanismos de uma dieta exclusiva. O objetivo desse trabalho foi verificar os efeitos da administração de xarope de glicose do milho a 15% após atividade física aguda forçada em esteira sobre a memória, a ansiedade, a atividade locomotora, a neuroplasticidade e a morte celular de camundongos machos. Foram formados 4 grupos, sendo sedentário controle (SED), treinado controle (TRE), sedentário administrado (SED15%) e treinado administrado (TRE15%). O regime de treinamento consistiu em atividade física forçada em esteira por 40 min a 0...

Calcified congenital arachnoid cyst with heterotopic neuroglia in wall.

Shuangshoti, S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1978 EN
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Two unique findings, advanced calcification and ectopic neuroglia, were encountered in the wall of a giant congenital arachnoid cyst occurring in a 40 year old woman. The cyst almost totally filled the supratentorial subdural space of the left hemicranial cavity, was not connected with the subarachnoid space, and thus developed intra-arachnoidally. Its congenitally derived nature was supported by the unique finding of heterotopic neuroglia in the wall. Congenital arachnoid cyst must be distinguished from various cystic lesions within the central nervous system, including the neuroepithelial cyst which can arise throughout the neuraxis. It is suggested that pathogenesis of the congenital arachnoid cyst is related to aberrant flow of the ventricular cerebrospinal fluid into the developing leptomeninx in the process of differentiation of the subarachnoid space. The tract or pouch may occur within the arachnoid mater, and the cyst is formed intra-arachnoidally when the former filled with fluid is closed off from the subarachnoid space.

Quantitative changes in neuroglia in the white matter of the mouse brain following hypoxic stress.

Sturrock, R R
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1976 EN
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27.13%
Two experimental and one control group of 70-80 day old mice were used in this study. The two experimental groups were subjected to hypoxia for 2 days in a decompression chamber at 390 mmHg. The animals in one experimental group were killed on removal from the chamber (hypoxic group) while those in the other (recovery group) were allowed to recover at sea-level atmospheric pressure for one week before being killed. Semithin, toluidine blue stained sections from the anterior limb of the anterior commissure were examined to find whether any quantitative changes occurred in the neuroglia with hypoxic stress. The following changes were observed: (1) The percentage of astrocytes in the hypoxic and recovery groups was significantly (P less than 0-005) lower than in the control group. (2) The percentage of oligodendrocytes in the hypoxic and recovery groups was significantly (P less than 0-001) higher than in the control group. (3) The percentage of microglia in the recovery groups was significantly (P less than 0-02) lower than in either of the other two groups. (4) The percentage of astrocytes in the recovery group was slightly (2-1%) higher than in the hypoxic group, and although not statistically significant, this result suggested that a slow return to normal might be occurring. (5) Little change was observed in cell density. The possible significance of these changes is discussed. I should like to express my indebtedness to Dr E.J. Clegg of the Department of Anatomy...

Extracellular potassium activity, intracellular and extracellular potential responses in the spinal cord.

Lothman, E W; Somjen, G G
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1975 EN
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1. Microcapillary electrode assemblies of two or three channels were used to record extracellular and intracellular potentials together with the extracellular activity of potassium ions, from essentially single locations within the substance of the decapitate spinal cord of cats. A liquid ion exchanger filled the tip of the potassium sensing microprobe. Activity was evoked by electrical stimulation of afferent peripheral nerves (ventral roots were cut). 2. Within the substance of the spinal grey matter increments of extracellular potassium activity evoked by repetitive afferent volleys were precisely correlated with magnitudes of sustained shifts of extracellular electric potential. Raising [K+]o from 3 to 4 mM was associated with a negative shift of potential of 2-5 +/- 0-5 mV, regardless of the position of the electrode in the tissue, and regardless of treatment by convulsant or depressant drugs. 3. The spatial distribution of the responses of potassium activity was mapped by the spatial distribution of the negative sustained potential shifts. 4. Depolarization shifts of potential recorded from within neuroglia cells ran parallel with changes of extracellular potassium potential. Even though the magnitude of extracellular sustained potential shifts was precisely correlated with the responses of both extracellular potassium and intracellular glial potentials...

A CONTRIBUTION TO THE STUDY OF HUMAN NEUROGLIA

Taylor, Edward Wyllys
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/11/1897 EN
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The results and conclusions of the above investigation are: 1. The term glio-sarcoma should be dropped, as unscientific and misleading in its significance. 2. The problems regarding neuroglia demand varied methods for their adequate study. 3. With all the means at our command, the absolute determination of the relation of cells and fibres in individual cases remains difficult and at times impossible. 4. No criterion has yet been offered to determine a fundamental distinction between glioma and sarcoma (Stroebe); and secondly, between glioma and so-called gliosis (Weigert). 5. The development of neuroglia in all probability is from cells with protoplasmic processes to cells with differentiated and independent fibres. 6. Herein lies a possible reconciliation of the conflicting views concerning the ultimate structure of human neuroglia.

Soluble Factors from Plasmodium falciparum-infected Erythrocytes Induce Apoptosis in Human Brain Vascular Endothelial and Neuroglia Cells

Wilson, Nana O.; Huang, Ming-Bo; Anderson, Winston; Bond, Vincent; Powell, Michael; Thompson, Winston E.; Armah, Henry B.; Adjei, Andrew A.; Gyasi, Richard; Tettey, Yao; Stiles, Jonathan K.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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27.63%
The severity of malaria is multi-factorial. It is associated with parasite-induced alteration in pro-inflammatory and anti-inflammatory cytokine and chemokine levels in host serum and cerebrospinal fluid. It is also associated with sequestration and cytoadherence of parasitized erythrocytes (pRBCs) in post-capillary venules and blood brain barrier (BBB) dysfunction. The role of these factors in development of vascular injury and tissue damage in malaria patients is unclear. While some studies indicate a requirement for pRBC adhesion to vascular endothelial cells (EC) in brain capillaries to induce apoptosis and BBB damage, others show no role of apoptosis resulting from adhesion of pRBC to EC. In the present study, the hypothesis that soluble factors from Plasmodium falciparum-infected erythrocytes induce apoptosis in human brain vascular endothelial (HBVEC) and neuroglia cells (cellular components of the BBB) was tested. Apoptotic effects of parasitized (pRBC) and non-parasitized erythrocyte (RBC) conditioned medium on HBVEC and neuroglia cells were determined in vitro by evaluating nuclear DNA fragmentation (TUNEL assay) in cultured cells. Soluble factors from Plasmodium falciparum-infected erythrocytes in conditioned medium induced extensive DNA fragmentation in both cell lines...

Localization of West Nile Virus in monkey brain: double staining antigens immunohistochemically of neurons, neuroglia cells and West Nile Virus

He, Xianli; Ren, Junping; Xu, Fangling; Ferguson, Monique R; Li, Guangyu
Fonte: e-Century Publishing Corporation Publicador: e-Century Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 15/11/2009 EN
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27.92%
West Nile virus (WNV) can cause encephalitis or meningitis that affects brain tissue, which can also lead to permanent neurological damage that can be fatal. To our knowledge, no consistent double immunohistochemical staining of neurons, neuroglia cells, and WNV has yet been reported. To establish a method for performing double-label immunohistochemical detection of neurons, neuroglia cells and WNV, examining the pathological characteristics of WNV-infected neurons, neuroglia cells, and investigating distribution of WNV in monkey brain, paraffin-embedded monkey brain tissue were retrospectively studied by immunohistochemical staining of neurons, neuroglia cells and WNV. Antibodies against neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP) and WNV were used to develop the method of double-label immunohistochemical staining, which allowed independent assessment of neuron status and WNV distribution. A range of immunohistochemical WNV infection in monkey brain was observed in both neurons and neuroglia cells in terms of the thickness of lesion staining, and the WNV staining was slightly higher in neuroglia cells than in neurons. All these findings suggest that WNV invasion in the brain plays a crucial role in neurological damage by inducing central nervous system (CNS) cell dysfunction or cell death directly.

Adaptogens Stimulate Neuropeptide Y and Hsp72 Expression and Release in Neuroglia Cells

Panossian, Alexander; Wikman, Georg; Kaur, Punit; Asea, Alexzander
Fonte: Frontiers Research Foundation Publicador: Frontiers Research Foundation
Tipo: Artigo de Revista Científica
Publicado em 01/02/2012 EN
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The beneficial stress–protective effect of adaptogens is related to the regulation of homeostasis via mechanisms of action associated with the hypothalamic–pituitary–adrenal axis and the regulation of key mediators of the stress response, such as molecular chaperones, stress-activated c-Jun N-terminal protein kinase, forkhead box O transcription factor, cortisol, and nitric oxide (NO). However, it still remains unclear what the primary upstream targets are in response to stimulation by adaptogens. The present study addresses this gap in our knowledge and suggests that an important target for adaptogen mediated stress–protective effector functions is the stress hormone neuropeptide Y (NPY). We demonstrated that ADAPT-232, a fixed combination of adaptogens Eleutherococcus senticosus root extract, Schisandra chinensis berry extract, Rhodiola rosea root extract SHR-5, and its active constituent salidroside, stimulated the expression of NPY and 72 kDa heat shock protein (Hsp72) in isolated human neuroglia cells. The central role of NPY was validated in experiments in which pre-treatment of human neuroglia cells with NPY-siRNA and HSF1-siRNA resulted in the significant suppression of ADAPT-232-induced NPY and Hsp72 release. Taken together our studies suggest that the stimulation and release of the stress hormones...

Neuroglia at the crossroads of homoeostasis, metabolism and signalling: evolution of the concept

Parpura, Vladimir; Verkhratsky, Alexei
Fonte: American Society for Neurochemistry Publicador: American Society for Neurochemistry
Tipo: Artigo de Revista Científica
Publicado em 01/05/2012 EN
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Ever since Rudolf Virchow in 1858 publicly announced his apprehension of neuroglia being a true connective substance, this concept has been evolving to encompass a heterogeneous population of cells with various forms and functions. We briefly compare the 19th–20th century perspectives on neuroglia with the up-to-date view of these cells as an integral, and possibly integrating, component of brain metabolism and signalling in heath and disease. We conclude that the unifying property of otherwise diverse functions of various neuroglial cell sub-types is to maintain brain homoeostasis at different levels, from whole organ to molecular.

Metabotropic glutamate receptor-mediated signaling in neuroglia

Loane, David J.; Stoica, Bogdan A.; Faden, Alan I.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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27.44%
Metabotropic glutamate (mGlu) receptors are G-protein-coupled receptors, which include eight subtypes that have been classified into three groups (I–III) based upon sequence homology, signal transduction mechanism and pharmacological profile. Although most studied with regard to neuronal function and modulation, mGlu receptors are also expressed by neuroglia-including astrocytes, microglia and oligodendrocytes. Activation of mGlu receptors on neuroglia under both physiologic and pathophysiologic conditions mediates numerous actions that are essential for intrinsic glial cell function, as well as for glial–neuronal interactions. Astrocyte mGlu receptors play important physiological roles in regulating neurotransmission and maintaining neuronal homeostasis. However, mGlu receptors on astrocytes and microglia also serve to modulate cell death and neurological function in a variety of pathophysiological conditions such as acute and chronic neurodegenerative disorders. The latter effects are complex and bi-directional, depending on which mGlu receptor sub-types are activated.

MRI reveals differential effects of amphetamine exposure on neuroglia in vivo

Liu, Christina H.; Yang, Jinsheng; Ren, Jia Q.; Liu, Charng-Ming; You, Zerong; Liu, Philip K.
Fonte: Federation of American Societies for Experimental Biology Publicador: Federation of American Societies for Experimental Biology
Tipo: Artigo de Revista Científica
Publicado em /02/2013 EN
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28.01%
How amphetamine affects the neuroglia in living brains is not well understood. In an effort to elucidate this effect, we investigated neuroglia in response to amphetamine exposure using antisense (AS) or sense (S) phosphorothioate-modified oligodeoxynucleotide (sODN) sequences that correspond to glial fibrillary acidic protein (GFAP) mRNA (AS-gfap or S-gfap, respectively) expression. The control is a random-sequence sODN (Ran). Using cyanine 5.5-superparamagnetic iron oxide nanoparticle (Cy5.5-SPION) labeling and fluorescent microscopy, we demonstrated that living neural progenitor cells (PC-12.1), as well as the cells in fresh brain slices and intact brains of male C57BL6 mice, exhibited universal uptake of all of the sODNs but rapidly excluded all sODN-Ran and most S-gfap. Moreover, transmission electron microscopy revealed electron-dense nanoparticles only in the neuroglia of normal or transgenic mice [B6;DBA-Tg(Fos-tTA, Fos-EGFP*)1MmayTg(tetO-lacZ,tTA*)1Mmay/J] that had been administered AS-gfap or Cy5.5-SPION-gfap. Subtraction R2* maps from mice with acute and chronic amphetamine exposure demonstrated, validated by postmortem immunohistochemistry, a reduction in striatal neuroglia, with gliogenesis in the subventricular zone and the somatosensory cortex in vivo. The sensitivity of our unique gene transcript targeted MRI was illustrated by a positive linear correlation (r2=1.0) between in vivo MRI signal changes and GFAP mRNA copy numbers determined by ex vivo quantitative RT-PCR. The study provides direct evidence for targeting neuroglia by antisense DNA-based SPION-gfap that enables in vivo MRI of inaccessible tissue with PCR sensitivity. The results enable us to conclude that amphetamine induces toxicity to neuroglia in vivo...

P2X receptors in neuroglia

Verkhratsky, Alexei; Pankratov, Yuri; Lalo, Ulyana; Nedergaard, Maiken
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Different types of ionotropic P2X purinoceptors are expressed in all major types of neuroglia, where they mediate a variety of physiological and pathological signaling. Cortical astrocytes express specific P2X1/5 heteromeric receptors that are activated by ongoing synaptic transmission and can trigger fast local signaling through elevation in cytoplasmic Ca2+ and Na+ concentrations. Oligodendrocytes express several types of P2X receptors that may control their development and mediate axonal–glial interactions. In microglia, P2X4 and P2X7 receptors regulate numerous events associated with microglial activation, motility, and release of proinflammatory factors.

Localization of NG2 immunoreactive neuroglia cells in the rat locus coeruleus and their plasticity in response to stress

Seifi, Mohsen; Corteen, Nicole L.; van der Want, Johannes J.; Metzger, Friedrich; Swinny, Jerome D.
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 14/05/2014 EN
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27.13%
The locus coeruleus (LC) nucleus modulates adaptive behavioral responses to stress and dysregulation of LC neuronal activity is implicated in stress-induced mental illnesses. The LC is composed primarily of noradrenergic neurons together with various glial populations. A neuroglia cell-type largely unexplored within the LC is the NG2 cell. NG2 cells serve primarily as oligodendrocyte precursor cells throughout the brain. However, some NG2 cells are in synaptic contact with neurons suggesting a role in information processing. The aim of this study was to neurochemically and anatomically characterize NG2 cells within the rat LC. Furthermore, since NG2 cells have been shown to proliferate in response to traumatic brain injury, we investigated whether such NG2 cells plasticity also occurs in response to emotive insults such as stress. Immunohistochemistry and confocal microscopy revealed that NG2 cells were enriched within the pontine region occupied by the LC. Close inspection revealed that a sub-population of NG2 cells were located within unique indentations of LC noradrenergic somata and were immunoreactive for the neuronal marker NeuN whilst NG2 cell processes formed close appositions with clusters immunoreactive for the inhibitory synaptic marker proteins gephyrin and the GABA-A receptor alpha3-subunit...

The Cajal school and the physiological role of astrocytes: a way of thinking

Navarrete, Marta; Araque, Alfonso
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 19/05/2014 EN
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Cajal is widely recognized by the scientific community for his important contributions to our knowledge of the neuronal organization of the nervous system. His studies on neuroglial cells are less recognized, yet they are no less relevant to our current understanding of the cellular bases of brain structure. Two pioneering studies published a century ago –“Something about the physiological significance of neuroglia” (Ramón y Cajal, 1897) and “A contribution to the understanding of neuroglia in the human brain” (Ramón y Cajal, 1913)—focused on glial cells and their role in brain physiology. Novel findings obtained using state-of-the-art and sophisticated technologies largely confirm many of the groundbreaking hypotheses proposed by Cajal related to the structural-functional properties of neuroglia. Here we propose to the reader a journey guided by the ideas of Cajal through the recent findings on the functional significance of astrocytes, the most abundant neuroglial cell type in the nervous system. Astrocyte–neuron interaction, which represents an emerging field in current neuroscience with important implications for our understanding of the cellular processes underlying brain function, has its roots in many of the original concepts proposed by Cajal.

EDITORIAL Neuroglia as a Central Element of Neurological Diseases: An Underappreciated Target for Therapeutic Intervention

Peng, Liang; Parpura, Vladimir; Verkhratsky, Alexei
Fonte: Bentham Science Publishers Publicador: Bentham Science Publishers
Tipo: Artigo de Revista Científica
EN
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27.44%
Neuroglia of the central nervous system (CNS), represented by cells of neural (astrocytes, oligodendrocytes and NG2 glial cells) and myeloid (microglia) origins are fundamental for homeostasis of the nervous tissue. Astrocytes are critical for the development of the CNS, they are indispensable for synaptogenesis, and they define structural organisation of the nervous tissue, as well as the generation and maintenance of CNS-blood and cerebrospinal fluid-blood barriers. Astroglial cells control homeostasis of ions and neurotransmitters and provide neurones with metabolic support. Oligodendrocytes, through the process of myelination, as well as by homoeostatic support of axons provide for interneuronal connectivity. The NG2 cells receive direct synaptic inputs, and might be important elements of adult remyelination. Microglial cells, which originate from foetal macrophages invading the brain early in embryogenesis, shape the synaptic connections through removing of redundant synapses and phagocyting apoptotic neurones. Neuroglia also form the defensive system of the CNS through complex and context-specific programmes of activation, known as reactive gliosis. Many neurological diseases are associated with neurogliopathologies represented by asthenic and atrophic changes in glial cells that...

Bacterial lipopolysaccharide induces a dose-dependent activation of neuroglia and loss of basal forebrain cholinergic cells in the rat brain

Houdek, Heidi M.; Larson, Jordan; Watt, John A.; Rosenberger, Thad A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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27.44%
In a rat model of neuroinflammation induced with a low-dose infusion lipopolysaccharide (5.0 ng/hr, LPS), we reported that brain arachidonic acid (ARA, 20:4 n-6), but not docosahexaenoic acid (DHA, 22:6n-3), metabolism is increased compared to control rats. To further characterize the impact LPS has on the induction of injury in this model, we quantified the dose-dependent activation of neuroglia and the loss of cholinergic cells in rats subjected to increasing doses of LPS. In this study, we found that LPS produced a statistically significant and linear dose-dependent increase in the percentage of activated CD11b-positive microglia ranging from 26% to 82% following exposure to doses ranging between 0.05 and 500 ng/hr, respectively. The percentage of activated GFAP-positive astrocytes also increased linearly and significantly from 35% to 91%. Significant astroglial scaring was evident at the lateral ventricular boarder of rats treated with 50 and 500 ng/hr LPS, but not evident in control treated rats or rats treated with lower doses of LPS. A dose-dependent decrease in the numbers of ChAT-positive cells in the basal forebrain of LPS-treated rats was found at higher doses of LPS (5, 50, and 500 ng/hr) but not at lower doses. The numbers of ChAT-positive cells within individual regions of the basal forebrain (medial septum and diagonal bands) and the composite basal forebrain were similar in their response. These data demonstrate that extremely low doses of LPS are sufficient to induce significant neuroglia activation while moderate doses above 5.0 ng/hr are required to induce cholinergic cell loss.

Immunocytochemical localization of cyclic GMP: Light and electron microscope evidence for involvement of neuroglia

Chan-Palay, V.; Palay, S. L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/1979 EN
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27.13%
Guanosine 3′,5′-cyclic monophosphate (cGMP) immunoreactivity in the rat's cerebellum was studied with light and electron microscopy by the indirect fluorescence method and the peroxidase-antiperoxidase method. Labeled cells included neuroglial cells in the cerebellar cortex, white matter, and deep nuclei; some stellate and basket cells in the cortex; and some large neurons in the deep nuclei. No evidence was found for sagittal microzonation in the cGMP distribution. In the labeled cells, cGMP immunoreactive sites were localized to surface membranes, organelles, and the cytoplasmic matrix. Specificity was indicated by the same pattern of labeling after treatment with cGMP immunoglobulin that had been adsorbed with adenosine 3′,5′-cyclic monophosphate (cAMP) and by the failure to label after treatment with normal rabbit sera or with cGMP immunoglobulin that had been adsorbed with 1 mM cGMP. Cerebella treated with cAMP antisera, however, showed immunoreactivity in Purkinje cells, granule cells, and Golgi cells in addition to neuroglia in cortex and deep nuclei. Sequential norepinephrine and glutamate superfusions generally intensified cGMP immunoreactivity, not only in neuroglial cells but also in the background. Under these conditions some Purkinje cells and some granule cells were also labeled. Increased cGMP immunoreactivity was also obtained by treatment with harmaline...

Acetate reduces PGE2 release and modulates phospholipase and cyclooxygenase levels in neuroglia stimulated with lipopolysaccharide

Soliman, Mahmoud L.; Ohm, Joyce E.; Rosenberger, Thad A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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27.13%
Acetate supplementation attenuates neuroglial activation, increases histone and non-histone protein acetylation, reduces pro-inflammatory cytokine expression, and increases IL-4 transcription in rat models of neuroinflammation and Lyme's neuroborreliosis. Because eicosanoid signaling is involved in neuroinflammation, we measured the effect acetate treatment had on phospholipase, cyclooxygenase, and prostaglandin E2 (PGE2) levels in BV-2 microglia and primary astrocytes stimulated with lipopolysaccharide (LPS). In BV-2 microglia, we found that LPS increased the phosphorylation-state of cytosolic phospholipase A2 (cPLA2), reduced the levels of phospholipase C (PLC) β1, and increased the levels of cyclooxygenase (Cox)-1 and -2. Acetate treatment returned PLCβ1 and Cox-1 levels to normal, attenuated the increase in Cox-2, but had no effect on cPLA2 phosphorylation. In primary astrocytes, LPS increased the phosphorylation of cPLA2 and increased the levels of Cox-1 and Cox-2. Acetate treatment in these cells reduced secretory PLA2 IIA and PLCβ1 levels as compared to LPS-treatment groups, reversed the increase in cPLA2 phosphorylation, and returned Cox-1 levels to normal. Acetate treatment reduced PGE2 release in astrocytes stimulated with LPS to control levels...