2018 Feb 7 – Among their heterogeneous and coordinating functions, astrocytes are implicated in the modulation of neuronal excitability and synaptic transmission. In particular, it has been suggested that astrocytes may influence the activity of local neural circuits controlling sleep, breathing and feeding via the vesicular release of signaling molecules called gliotransmitters. In a novel study, researchers collaborating across UK, US and the Russian Federation employed molecular approaches aimed at blocking or stimulating such release in the preBötzinger complex of adult conscious rats, where essential respiratory rhythm-generating circuits are located. The results show that astrocytes in the preBötzinger complex 1) modulate the respiratory rhythm-generating circuits, 2) critically mediate respiratory adaptive responses in conditions of increased metabolic demand and 3) contribute to determine the exercise capacity (i.e. the maximal oxygen uptake during exercise).