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Metabolism and Release of Glutamate in Cerebellar Granule Cells Cocultured with Astrocytes from Cerebellum or Cerebral Cortex
Author(s) -
Westergaard Niels,
Fosmark Hanne,
Schousboe Arne
Publication year - 1991
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1991.tb02562.x
Subject(s) - cerebellum , granule (geology) , astrocyte , glutamate receptor , biology , cerebral cortex , cerebellar cortex , neuroglia , microbiology and biotechnology , neuroscience , granule cell , glutamine , central nervous system , biochemistry , dentate gyrus , receptor , paleontology , amino acid
Cerebellar granule cells were cocultured with astrocytes from either cerebral cortex or cerebellum in two different systems. In one system the cells were plated next to each other only sharing the culture medium (separated cocultures) and in the other system the granule cells were plated on top of a preformed layer of astrocytes (sandwich cocultures). Using astrocytes from cerebellum, granule cells developed morphologically and functionally showing a characteristic high activity of the glutamate synthesizing enzyme aspartate aminotransferase (AAT) as well as a high stimuluscoupled transmitter release regardless of the culture system, i.e., granule cells could grow on top of cerebellar astrocytes as well as next to these cells. In the case of cerebral cortex astrocytes it was found that cerebellar granule cells did not develop (11% survival) when seeded on top of these astrocytes. This was indicated by the morphological appearance of the cultures as well as by a negligible difference between the AAT activity in sandwich cocultures and astrocytes cultured alone. On the other hand, granule cells in separated cocultures with cerebral cortex astrocytes exhibited a normal morphology and a high activity of AAT as well as a large stimulus‐coupled transmitter release. Cerebellar and cortical astrocytes expressed the astrocyte specific enzyme glutamine synthetase in a glucocorticoid‐inducible form regardless of the culture system. The results show that under conditions of direct contact between granule cells and astrocytes, regional specificity exists with regard to neuron‐glia contacts. This specificity does not seem to involve soluble factors present in the culture medium because in separated cocultures the cerebellar granule cells developed normally regardless of the regional origin of the astrocytes.