TY - JOUR
T1 - Endogenous Glutamate Levels Regulate Nerve Growth Factor mRNA Expression in the Rat Dentate Gyrus
AU - Gwag, Byoung Joo
AU - Sessler, Francis M.
AU - Robine, Veronique
AU - Springer, Joe E.
PY - 1997/6/30
Y1 - 1997/6/30
N2 - The levels of nerve growth factor (NGF) mRNA can be regulated in vitro and in vivo in the hippocampal formation by events associated with pharmacological activation of glutamate receptors. In the present study, the level of NGF mRNA in the hippocampal formation was examined following an intrahippocampal injection of 1 nmole fluorocitrate, which temporarily inhibits the astrocyte metabolic activity in vivo. Consistent with previous findings, fluorocitrate treatment significantly increased glutamate levels and decreased glutamine levels in the dentate gyrus as determined by in vivo microdialysis. The increased ratio of glutamate to glutamine was followed by a significant increase in NGF mRNA expression selectively in dentate gyrus granule cells. The effects of increasing glutamate levels were blocked by pretreatment with 50 nmole 2-amino-5-phosphonovalerate (AP5), a competitive antagonist that acts at the N-methyl-D-aspartate (NMDA) glutamate receptor subtype. These findings suggest that NGF mRNA expression is regulated, in part, by changes in endogenous glutamate levels, partially through enhanced excitatory neuro-transmission through NMDA receptors.
AB - The levels of nerve growth factor (NGF) mRNA can be regulated in vitro and in vivo in the hippocampal formation by events associated with pharmacological activation of glutamate receptors. In the present study, the level of NGF mRNA in the hippocampal formation was examined following an intrahippocampal injection of 1 nmole fluorocitrate, which temporarily inhibits the astrocyte metabolic activity in vivo. Consistent with previous findings, fluorocitrate treatment significantly increased glutamate levels and decreased glutamine levels in the dentate gyrus as determined by in vivo microdialysis. The increased ratio of glutamate to glutamine was followed by a significant increase in NGF mRNA expression selectively in dentate gyrus granule cells. The effects of increasing glutamate levels were blocked by pretreatment with 50 nmole 2-amino-5-phosphonovalerate (AP5), a competitive antagonist that acts at the N-methyl-D-aspartate (NMDA) glutamate receptor subtype. These findings suggest that NGF mRNA expression is regulated, in part, by changes in endogenous glutamate levels, partially through enhanced excitatory neuro-transmission through NMDA receptors.
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U2 - 10.1016/s1016-8478(23)13316-4
DO - 10.1016/s1016-8478(23)13316-4
M3 - Article
C2 - 9264033
AN - SCOPUS:0031591477
SN - 1016-8478
VL - 7
SP - 425
EP - 430
JO - Molecules and Cells
JF - Molecules and Cells
IS - 3
ER -