Anales RANF

S16-03 ROLE OF ASTROCYTIC ADENOSINE ON THE MODULATION OF SYNAPTIC PLASTICITY BY BDNF Sandra H. Vaz 1,2 , Joana Gomes 1,2 , João Jesus 1,2 , Ana M. Sebastião 1,2 1 Instituto de Medicina Molecular (iMM), Faculdade de Medicina da Universidade de Lisboa, Universidade de Lisboa; 2 Instituto de Farmacologia e Neurociências, Faculdade de Medicina da Universidade de Lisboa, Universidade de Lisboa. Astrocytes are key cellular partners to neurons, playing an important role in multiple processes in the brain. The concept of the tripartite synapse suggests that astrocytes are not only supportive cells with homeostatic functions, but that they also play a role in information processing by responding to neuronal synaptic activity with Ca 2+ elevations that induce the subsequent release of gliotransmitters which in turn modulate neuronal excitability and synaptic plasticity. Hippocampal long-term potentiation (LTP) is a sustained enhancement of excitatory synaptic strength believed to underlie learning and memory processes; it has recently been described that astrocytes regulate synaptic transmission and play a role in shaping LTP. Specifically, the release of gliotransmitters, such as glutamate, ATP, and D-serine likely alters the viability and functioning of newly formed connections. Other very important molecule for the modulation of LTP is brain-derived neurotrophic factor (BDNF), a neurotrophin involved in the development and protection of different neuronal population in the nervous system. Furthermore BDNF has a facilitatory action upon hippocampal LTP, being this action dependent on the adenosine A 2A receptor (A 2A R) activation. Thus, we evaluated 1) the involvement of astrocytes upon the modulatory effect of BDNF upon LTP, 2) the involvement of adenosine (and A 2A R) on this process and 3) the role of adenosine receptors activation on calcium signalling mediated by astrocytes. Main findings allow to suggest that BDNF effect upon synaptic plasticity is under the control of astrocytes. These results further highlight the role of astrocytes in the CNS, but more importantly the role of astrocytes on the glial–neuron communication involving synaptic plasticity modulation by neurotrophins. BDNF was kindly supplied by Regeneron Pharmaceuticals. This project was funded by Fundação para a Ciência e a Tecnologia (PTDC/BTM-SAL/32147/2017 and SFRH/BPD/81627/2011).