TY - JOUR
T1 - Astrocytes are required for the oscillatory activity in cultured hippocampal neurons
AU - Verderio, Claudia
AU - Bacci, Alberto
AU - Coco, Silvia
AU - Pravettoni, Elena
AU - Fumagalli, Guido
AU - Matteoli, Michela
PY - 1999/8
Y1 - 1999/8
N2 - Synchronous oscillations of intracellular calcium concentration ([Ca2+](i)) and of membrane potential occurred in a limited population of glutamatergic hippocampal neurons grown in primary cultures. The oscillatory activity occurred in synaptically connected cells only when they were in the presence of astrocytes. Microcultures containing only one or a few neurons also displayed oscillatory activity, provided that glial cells participated in the network. The glutamate-transporter inhibitors L-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) and dihydrokainate, which produce an accumulation of glutamate in the synaptic microenvironment, impaired the oscillatory activity. Moreover, in neurons not spontaneously oscillating, though in the presence of astrocytes, oscillations were induced by exogenous L-glutamate, but not by the stereoisomer D-glutamate, which is not taken up by glutamate transporters. These data demonstrate that astrocytes are essential for neuronal oscillatory activity and provide evidence that removal of glutamate from the synaptic environment is one of the major mechanisms by which glial cells allow the repetitive excitation of the postsynaptic cell.
AB - Synchronous oscillations of intracellular calcium concentration ([Ca2+](i)) and of membrane potential occurred in a limited population of glutamatergic hippocampal neurons grown in primary cultures. The oscillatory activity occurred in synaptically connected cells only when they were in the presence of astrocytes. Microcultures containing only one or a few neurons also displayed oscillatory activity, provided that glial cells participated in the network. The glutamate-transporter inhibitors L-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) and dihydrokainate, which produce an accumulation of glutamate in the synaptic microenvironment, impaired the oscillatory activity. Moreover, in neurons not spontaneously oscillating, though in the presence of astrocytes, oscillations were induced by exogenous L-glutamate, but not by the stereoisomer D-glutamate, which is not taken up by glutamate transporters. These data demonstrate that astrocytes are essential for neuronal oscillatory activity and provide evidence that removal of glutamate from the synaptic environment is one of the major mechanisms by which glial cells allow the repetitive excitation of the postsynaptic cell.
KW - Astrocytes
KW - Glutamate transporters
KW - Oscillations
KW - Rat hippocampal neurons
KW - Synaptic transmission
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U2 - 10.1046/j.1460-9568.1999.00697.x
DO - 10.1046/j.1460-9568.1999.00697.x
M3 - Article
C2 - 10457176
AN - SCOPUS:0032838877
VL - 11
SP - 2793
EP - 2800
JO - European Journal of Neuroscience
JF - European Journal of Neuroscience
SN - 0953-816X
IS - 8
ER -