Dr. Sandra H. Vaz, ASebastião Lab, Department of Molecular Medicine, University of Lisbon & Department of Pharmacology and Neuroscience, Faculty of Medicine, University of Lisbon

Astrocytes, gliotransmitters and BDNF: working together to shape synaptic plasticity?

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 Ca²⁺ 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 and recently has 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 the brain-derived neurotrophic factor (BDNF).  BDNF is a growth factor involved in the development and maintenance 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_2AR) activation.

Thus is important to study the involvement of astrocytes upon the modulatory effect of BDNF upon LTP, the possible involvement of adenosine (and A_2AR) on this process and the role of adenosine receptors activation on calcium signalling mediated by astrocytes. These results will have a big impact in understanding the role of astrocytes in the CNS, but more importantly the role of astrocytes on the glial–neuron communication and on the effect of BDNF at synaptic levels.

Host: Associate professor Brigitte Maria Städler, iNANO & Department of Molecular Biology and Genetics