Neuroprotective activity of the conditioned medium collected from pure cultures of astrocytes 20 hr after a 10 min exposure to the indicated mGlu receptor agonists. CTRL, Control medium (i.e., medium collected from astrocyte cultures treated with the buffer alone). DCG-IV, 1 μm;4C3HPG, 50 μm; L-CCG-I, 10 μm; l-AP4, 10 μm; DHPG, 50 μm. Values (mean ± SEM) were calculated from three to five independent experiments (n = 4 individual wells in each experiment). *p < 0.01 (one-way ANOVA + Fisher PLSD) when compared with CTRL.