Figure 1
From: An autocrine purinergic signaling controls astrocyte-induced neuronal excitation
ChR2 photoactivation of astrocytes increases neuronal activity. (a) Immunohystochemical localization of ChR2-EYFP, glutamine synthetase (GS) and NeuN in the CA1 region of the hippocampus of Cx30-CreERT2:ChR2-EYFP mice. ChR2-EYFP expression is selectively confined to GS-expressing astrocytes and not to NeuN immunoreactive neurons. (b) Current clamp traces and corresponding raster plots illustrating the responses of CA1 neurons to light activation of astrocytes (light blue marks in all figures) before and after application of 50 µM D-AP5. The traces shown correspond to cell number 5 in the raster plots. A constant depolarizing current was injected throughout recordings to bring membrane potential near action potential threshold. (c) Number of action potentials during 5 s time windows before and during photostimulation of astrocytes in control conditions and in the presence of D-AP5 (control: t(5) = 7.603, P = 0.0006; D-AP5: t(5) = 0.674, P = 0.53; 6 cells, 3 animals, paired t-test). (d) Example of a CA1 pyramidal neuron responding to light stimulation of astrocytes by an excitation-inhibition sequence and block of the inhibition by the adenosine A1 receptor antagonist DPCPX (300 nM). (e) Number of action potentials during 10 s time windows before and after photostimulation of astrocytes in control conditions and in the presence of DPCPX (control: t(5) = 2.957, P = 0.032; DPCPX: t(5) = 1.431, P = 0.212, 6 cells, 4 animals, paired t-test). For all figures n.s. P > 0.05, *P < 0.05, **P < 0.01, ***P < 0.001.
