Adenosine released by astrocytes contributes to hypoxia-induced modulation of synaptic transmission

ATP; presynaptic modulation; synaptic plasticity; astrocyte modulation Astrocytes play a critical role in brain homeostasis control-ling the local environment in normal as well as in patholog-ical conditions, such as during hypoxic/ischemic insult. Since astrocytes have recently been identified as a source for a wide variety of gliotransmitters that modulate synap-tic activity, we investigated whether the hypoxia-induced excitatory synaptic depression might be mediated by adeno-sine release from astrocytes. We used electrophysiological and Ca21 imaging techniques in hippocampal slices and transgenic mice, in which ATP released from astrocytes is specifically impaired, as well as chemiluminescent and fluo-rescence photometric Ca21 techniques in purified culture