Abstract:
:The uptake of L-glutamate was studied in astrocytes cultured from different brain areas of newborn rats as well as in two different cultures of neurons obtained from mouse brain. Both astrocytes and neurons exhibited high-affinity glutamate uptake with Km values ranging from 34 microM to 82 microM. Vmax values for astrocytes cultured from the different brain regions were: prefrontal cortex: 13.9; occipital cortex: 11.4; neostriatum: 27.3 and cerebellum: 5.8 nmol X min-1 X mg-1 cell protein. For cerebellar granule cells and cerebral cortical neurons the Vmax values were found to be 10.2 and 5.9 nmol X min-1 X mg-1 cell protein, respectively. The effect on L-glutamate uptake in astrocytes cultured from prefrontal cortex and in cultured cerebellar granule cells of a series of compounds structurally related to glutamate was studied, and detailed kinetic analyses of the inhibitory patterns of three potent inhibitors were performed. L-aspartate and L-aspartate-beta-hydroxamate were found to be competitive inhibitors of L-glutamate uptake in both cell types with Ki values for astrocytes of 60 microM and 91 microM, respectively, and for granule cells of 48 microM and 72 microM, respectively. D-aspartate was found to be a mixed-type noncompetitive inhibitor of L-glutamate uptake in astrocytes (Ki: 106 microM), but in granule cells this compound showed simple competitive inhibition with a Ki of 49 microM. Sodium dependency of L-glutamate uptake in both cell types was studied at a series of L-glutamate and Na+ concentrations. It was found that the uptake of glutamate in astrocytes is coupled with one Na+ ion in contrast to two Na+ ions in granule cells. The Km value for sodium was found to be 15 mM in both cell types. It was shown that release of exogenously supplied [3H]-L-glutamate from cerebellar granule cells could be stimulated in a Ca2+-dependent manner by high concentrations (55 mM) of K+. In contrast to this no K+-induced release of glutamate could be demonstrated in cultured astrocytes.
journal_name
Exp Brain Resjournal_title
Experimental brain researchauthors
Drejer J,Larsson OM,Schousboe Adoi
10.1007/BF00239385subject
Has Abstractpub_date
1982-01-01 00:00:00pages
259-69issue
2eissn
0014-4819issn
1432-1106journal_volume
47pub_type
杂志文章abstract::In drawing a copy of a geometrical shape, a sequence of movements must be produced to represent the sides of the object in the proper spatial relationship. We investigated neural mechanisms of this process by training monkeys to draw (using a joystick) copies of geometrical shapes (triangles, squares, trapezoids and i...
journal_title:Experimental brain research
pub_type: 杂志文章
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journal_title:Experimental brain research
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journal_title:Experimental brain research
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journal_title:Experimental brain research
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journal_title:Experimental brain research
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journal_title:Experimental brain research
pub_type: 杂志文章
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pub_type: 杂志文章
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journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/BF00237394
更新日期:1978-05-12 00:00:00
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journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/BF00229836
更新日期:1991-01-01 00:00:00
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journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/BF00228400
更新日期:1993-01-01 00:00:00
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journal_title:Experimental brain research
pub_type: 杂志文章
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journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/BF00230100
更新日期:1990-01-01 00:00:00
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journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/s002210050672
更新日期:1999-03-01 00:00:00
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journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/BF00235934
更新日期:1985-01-01 00:00:00
abstract::Chronic loss of vestibular function modifies the role of neck afferents in human perception of self-motion. We characterized this change by comparing the self-motion perception of patients with chronic vestibular loss (Ps) to that of normal subjects (Ns). Stimuli consisted of sinusoidal horizontal rotations (0.025-0.4...
journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/BF00227147
更新日期:1993-01-01 00:00:00
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doi:10.1007/s00221-014-4129-0
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pub_type: 杂志文章
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journal_title:Experimental brain research
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pub_type: 杂志文章
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更新日期:2005-08-01 00:00:00
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pub_type: 杂志文章
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更新日期:2008-12-01 00:00:00
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journal_title:Experimental brain research
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更新日期:2009-08-01 00:00:00
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更新日期:2003-10-01 00:00:00
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journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/BF00279654
更新日期:1988-01-01 00:00:00
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journal_title:Experimental brain research
pub_type: 杂志文章
doi:10.1007/s002210050428
更新日期:1998-06-01 00:00:00
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pub_type: 杂志文章
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更新日期:1999-02-01 00:00:00