Diacylglycerol Signaling Underlies Astrocytic ATP Release
Figure 1
The diacylglycerol analogue 1-oleoyl-2-acyl-sn-glycerol (OAG) induces calcium oscillations in astrocytes that are not dependent on external calcium. (a) Cultured cortical astrocytes respond to 100 μM OAG with robust calcium oscillations. (b) Astrocytes imaged in culture in a perfusion system have little background calcium activity as imaged with Fluo4. (c) The addition of 100 μM OAG causes increases in the Fluo4 signal in discrete astrocytes but does not result in a calcium wave. (d) Astrocyte calcium oscillations continue for several minutes after the OAG-containing medium is washed away. (e) Calcium oscillation in response to 30 μM OAG is not reduced in the presence of nominally (~60 nM) calcium-free external medium (). (f) The astrocyte response to 30 μM OAG is significantly greater than the response to the less cell-permeable DAG analogue 1-stearoyl-2-arachidonyl-sn-glycerol (SAG, 30 μM) (, control , SAG ).
