Supporting information for Gärtner and Staiger (2002) Proc. Natl. Acad. Sci. USA 99 (9), 6386–6391. (10.1073/pnas.092129699)
Fig. 7.
Astrocytes do not show regulated brain-derived neurotrophic factor (BDNF) secretion in response to 50 Hz or to Glu stimulation. Astrocytes were prepared by enzymatic dissociation of cortices or hippocampi of E19 Wistar rat embryos. Cells were plated on uncoated 24-well plates. Neurons, which cannot attach to uncoated plates, were removed after 3 h and the remaining astrocytes were grown in DMEM/10% HS and were regularly vigorously shaken during the first week of culturing. BDNF secretion experiments were performed under the same conditions as described for neurons. Six hundred stimuli at 50 Hz applied as bursts or trains did not trigger BDNF secretion. Application of 1 mM Glu (Fig. 7) also did not cause any regulated secretion from astrocytes. Values given represent the mean ± SEM (n = 12). The differences compared to basal values are not significant (P > 0.05). Moreover, in neuronal cultures that also contained a large number of astrocytes, which are readily transduced, regulated secretion was not detectable, because the high rates of constitutive secretion from astrocytes masked any regulated secretion from neurons. This effect is enhanced by the fact that astrocytes, which are preferentially transduced by adenoviral vectors, prevent an effective transduction of neurons. These data demonstrate that astrocytes under our regular conditions (<3% of astrocytes) contribute to the constitutive secretion only, and not to the regulated BDNF secretion.