• neuroscience
  • Dogma is slow to change, and one of the dogmas of neuroscience is that astrocytes are support cells that don't do much themselves," said Oberheim. (innovations-report.com)
  • Only 5 percent of astrocytes become infected with HIV, according to Eliseo Eugenin, PhD, assistant professor of pathology at the Albert Einstein College of Medicine of Yeshiva University in New York, who was the lead researcher on the study published June 29 in The Journal of Neuroscience . (lww.com)
  • Such discoveries have made astrocytes an important area of research within the field of neuroscience. (wikipedia.org)
  • reactive
  • Reactive astrocytes are prominent in the cellular response to spinal cord injury (SCI), but their roles are not well understood. (jneurosci.org)
  • Mice expressing a glial fibrillary acid protein-herpes simplex virus-thymidine kinase transgene were given mild or moderate SCI and treated with the antiviral agent ganciclovir (GCV) to ablate dividing, reactive, transgene-expressing astrocytes in the immediate vicinity of the SCI. (jneurosci.org)
  • Equivalent small stab injuries in transgenic mice given GCV to ablate reactive astrocytes caused failure of blood-brain barrier repair, leukocyte infiltration, local tissue disruption, severe demyelination, neuronal and oligodendrocyte death, and pronounced motor deficits. (jneurosci.org)
  • Equivalent moderate crush injuries combined with ablation of reactive astrocytes caused widespread tissue disruption, pronounced cellular degeneration, and failure of wound contraction, with severe persisting motor deficits. (jneurosci.org)
  • These findings show that reactive astrocytes provide essential activities that protect tissue and preserve function after mild or moderate SCI. (jneurosci.org)
  • Our findings suggest that identifying ways to preserve reactive astrocytes, to augment their protective functions, or both, may lead to novel approaches to reducing secondary tissue degeneration and improving functional outcome after SCI. (jneurosci.org)
  • Reactive astrocytes are a prominent feature of the cellular response to SCI. (jneurosci.org)
  • Rudge and Silver, 1990 ), and reactive astrocytes are often regarded as detrimental to functional outcome after SCI and other forms of CNS injury. (jneurosci.org)
  • In this regard, a role for reactive astrocytes has long been postulated in CNS wound healing, but the precise nature and relative importance of that role are unknown. (jneurosci.org)
  • The continuation, augmentation, and appropriate regulation of astrocyte functions are likely to be important after SCI, but the activities of reactive astrocytes are not well defined. (jneurosci.org)
  • To investigate the roles of reactive astrocytes after SCI, we selectively and conditionally targeted their deletion in adult transgenic mice after SCI, using a well characterized transgenic model (Bush et al. (jneurosci.org)
  • Astrocytes can also respond to CNS injury by undergoing reactive gliosis. (wikipedia.org)
  • morphological
  • Although many of these specific modulatory relationships are not yet fully understood, it is known that different specific signaling mechanisms result in different morphological and functional changes of astrocytes, allowing astrogliosis to take on a graduated spectrum of severity. (wikipedia.org)
  • blood-brain b
  • Astrocytes also play a key role in maintaining the blood-brain barrier. (lww.com)
  • In cell culture, Dr. Eugenin showed, infection of only a small percentage of astrocytes caused a disruption of the blood-brain barrier, increasing its permeability to molecules normally excluded, including large proteins, and leading to apoptosis of endothelial cells. (lww.com)
  • A principal function of pericytes is to interact with astrocytes, smooth muscle cells, and other intracranial cells to form the blood brain barrier and to modulate the size of blood vessels to ensure proper delivery and distribution of oxygen and nutrients to neuronal tissues. (wikipedia.org)
  • Regulation
  • Since malic enzyme contributes to the overall regulation of malate metabolism, we determined the activity and kinetics of the mitochondrial and cytosolic forms of this enzyme from cultured astrocytes. (springer.com)
  • uptake
  • α-ketoglutarate and malate uptake and metabolism by synaptosomes: Further evidence for an astrocyte-to-neuron metabolic shuttle. (springer.com)
  • disruption
  • Cerebellar defects included a loss in the numbers of astrocytes and an overall reduction in cerebellar size and disruption of the normally well defined cellular layers. (jneurosci.org)
  • mitochondrial
  • The results demonstrate that mitochondrial and cytosolic malic enzymes have different kinetic parameters and are regulated differently by endogenous compounds previously shown to alter malate metabolism in astrocytes. (springer.com)
  • In previous studies of hepatic encepalopathy, the presence of Alzheimer type II astrocytes corresponded to mitochondrial degeneration, as well as previously known phenotypic characteristics such as a prominent nucleolus and enlarged pale nuclei. (wikipedia.org)
  • calcium
  • So Nedergaard devised a new way to "listen" for astrocyte activity, developing a sophisticated laser system to look at their activity by measuring the amount of calcium inside the cells. (innovations-report.com)
  • We tested the hypotheses that key clock genes in astrocytes drive circadian oscillations in ATP release through either calcium- or vesicle-dependent mechanisms. (jneurosci.org)
  • We developed a novel, real-time assay and found that circadian ATP release depends on Clock , Per1 , and Per2 expression and IP 3 -dependent calcium signaling in astrocytes. (jneurosci.org)
  • When these calcium ion waves spread down the length of the astrocyte, phospholipase A (PLA2) is activated which in turn mobilizes arachidonic acid. (wikipedia.org)
  • roles
  • Astrocytes have been proposed to have multiple roles in the development and maintenance of the vertebrate CNS. (jneurosci.org)
  • Surprisingly, although multiple critical roles now have been assigned to astrocytes, few CNS defects have been attributed specifically to faulty functioning of these cells. (jneurosci.org)
  • Astrocytes are by far the most numerous cell type in the central nervous system (CNS) and have critical roles in adult CNS homeostasis. (thermofisher.com)
  • hepatic encephalopathy
  • In addition, astrocytes have been implicated in the pathogenesis of both hepatic encephalopathy ( Butterworth, 1993 ) and Alexander's disease ( Borrett and Becker, 1985 ). (jneurosci.org)
  • Alzheimer type II astrocytes are present in hepatic encephalopathy and Wilson's disease. (wikipedia.org)
  • The presence of Alzheimer type II astrocytes is a key indicator of hepatic encephalopathy, and may be induced by increased bodily ammonia. (wikipedia.org)
  • In hepatic encephalopathy, Alzheimer type II astrocytes are characterized by thin chromatin and increased glycogen levels. (wikipedia.org)
  • influx
  • It has also been proposed that NO may amplify astrocyte Ca2+ influx and activate Ca2+-dependent potassium channels, releasing K+ into the interstitial space and inducing hyperpolarization of smooth muscle cells. (wikipedia.org)
  • precursors
  • After astrocyte specification has occurred in the developing CNS, it is believed that astrocyte precursors migrate to their final positions within the nervous system before the process of terminal differentiation occurs. (wikipedia.org)
  • cells
  • Astrocytes had long been considered passive support cells, a means to hold the rest of the brain cells together, like glue. (innovations-report.com)
  • Astrocytes, once thought little more than passive, structurally supportive brain cells, are increasingly recognized as having a range of important properties and functions, such as the ability to release chemical messengers and signal to other cells. (ucl.ac.uk)
  • Astrocytes (or glial cells), previously assumed to be passive players in brain physiology, may play a functional role in a number of complex behaviors. (sciencemag.org)
  • The finding spotlights a group of cells that, until recently, were thought to be "uninteresting" for understanding neuroAIDS, since so few astrocytes are infected with the virus. (lww.com)
  • Although astrocytes are often broadly categorized as one cell type, a lot of diversity exists in the functions carried out by these cells," said co-senior author Dr. Chad Creighton, associate professor of medicine and member of the Dan L Duncan Comprehensive Cancer Center Division of Biostatistics at Baylor. (medindia.net)
  • One of the interests of the Deneen lab is identifying mechanisms that regulate astrocyte development and how these cells contribute to neurological diseases, in particular human glioblastoma multiforme, the most aggressive and deadly type of brain tumor. (medindia.net)
  • In these type of cancer, about 80 percent of the tumor comprises transformed astrocyte-like cells, and, just as in the case of normal brain tissue, the diversity of these tumor cell subpopulations and functions in brain tumors had not been studied in detail. (medindia.net)
  • I examined the expression of molecular markers of astrocytes as a measure of the integrity of these cells in schizophrenia. (umich.edu)
  • THURSDAY, June 19 (HealthDay News) -- Star-shaped brain cells called astrocytes play a key role in allowing experts to see the many reds, oranges, yellows and blues on brain scans, according to a report by researchers at the Massachusetts Institute of Technology. (bio-medicine.org)
  • This work shows that astrocytes, which make up 50 percent of the cells in the cortex but whose function was unknown, respond exquisitely to sensory drive, regulate local blood flow in the cortex and even influence neuronal responses," Sur said. (bio-medicine.org)
  • Pacey and Doering (2007) found that FMRP was expressed in early development in cells of the glial lineage both in vitro and in vivo , but not in adult astrocytes. (jneurosci.org)
  • Astrocytes (Astro from Greek astron = star and cyte from Greek "kytos" = cavity but also means cell), also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord. (wikipedia.org)
  • Astrocytes are a sub-type of glial cells in the central nervous system. (wikipedia.org)
  • The origin of Alzheimer type II astrocytes is unclear, although they are known to arise from astroglial cells in the development of Wilson's disease. (wikipedia.org)
  • Ultimately, the astrocytes form a dense web of their plasma membrane extensions that fills the empty space generated by the dead or dying neuronal cells (a process called astrogliosis). (wikipedia.org)
  • These consist of endothelial cells and smooth muscle, and as these pial arteries further branch and run deeper into the brain, they associate with glial cells, namely astrocytes and pericytes. (wikipedia.org)
  • Various cell types play a role in HR, including astrocytes, smooth muscle cells, endothelial cells of blood vessels, and pericytes. (wikipedia.org)
  • It has been shown that S100B is only expressed by a subtype of mature astrocytes that ensheath blood vessels and by NG2-expressing cells. (wikipedia.org)
  • S100B is secreted by astrocytes or can spill from injured cells and enter the extracellular space or bloodstream. (wikipedia.org)
  • However, the results of the study did not point at significant mutations in Fañanas cells but rather described the possible importance of astrocytes in general in the aetiology of CJD. (wikipedia.org)
  • molecules
  • I studied structural and functional molecules in astrocytes to determine 1) whether astrocytes are themselves globally compromised in schizophrenia, and 2) whether abnormal expression of glutamatergic molecules in astrocytes could be a contributing factor to brain dysfunction in this illness. (umich.edu)
  • Particularly, astrocytes closest to the lesion generally secrete more inhibitory molecules into the extracellular matrix. (wikipedia.org)
  • Further, the astrocytes secrete several growth-inhibitory molecules that chemically prevent axonal extensions. (wikipedia.org)
  • regulate
  • Thus, brainstem astrocytes have the ability to sense changes in blood and brain CO 2 , and pH directly, and may control the activity of the respiratory neuronal networks to regulate breathing. (sciencemag.org)
  • Histological
  • Histological examination revealed disrupted astrocyte development, particularly in the cerebellum, with marked secondary effects on other cell types. (jneurosci.org)
  • suggests
  • This suggests that manganism, a neurological disorder with Parkinson's-like symptoms, is caused by the development of these astrocytes through manganese poisoning. (wikipedia.org)
  • abundant
  • Astrocytes are the most abundant cell type in the vertebrate CNS, yet their versatility and importance are only beginning to be appreciated. (jneurosci.org)
  • found
  • Given that we found diverse astrocyte subpopulations, we wondered whether these subpopulations could also explain astrocyte contributions to a host of different neurological diseases," Deneen said. (medindia.net)
  • I found that the intermediate-filament glial fibrillary acidic protein (GFAP), a component of the astrocyte cytoskeleton, was significantly altered in the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) in schizophrenia. (umich.edu)
  • Alzheimer type II astrocytes may be found in both cortical and subcortical areas, including the brain stem, cerebellum, cerebral cortex, and thalamus. (wikipedia.org)
  • More specifically, these astrocytes are found in close proximity to the 'end feet' of blood vessels. (wikipedia.org)
  • It is also found in rat astrocytes. (wikipedia.org)
  • GFAP
  • Our current understanding of astrocyte form and distribution is based predominately on studies that used the astrocytic marker glial fibrillary acidic protein (GFAP) and on studies using metal-impregnation techniques. (jneurosci.org)
  • The severity of astrogliosis is classically determined by the level of expression of glial fibrillary acidic protein (GFAP) and vimentin, both of which are upregulated with the proliferation of active astrocytes. (wikipedia.org)
  • GFAP is an important intermediate filament protein that allows the astrocytes to begin synthesizing more cytoskeletal supportive structures and extend pseudopodia. (wikipedia.org)