Fig. 9.
Gαo2 downregulates monoamine uptake into permeabilized raphe neurons. A, Raphe neurons cultivated for 25 d in vitro were treated with either buffer or pertussis toxin (Ptx; 100 ng/ml) 2 d before the experiment. The experiment followed the protocol described in Figure 8. GMppNp or GTPγS was applied at 50 μmtogether with [3H]serotonin, and incubation was stopped after 10 min (*,**p < 0.04 or 0.05, respectively). B, This experiment followed a similar experimental design, with the exception that cultures were treated with TeNt (1 nm) 2 d before the experiment (*p < 0.02; **p < 0.03; ***p < 0.004; ****p < 0.05, calculated by Students' t test). Values are the mean of three cultures ± SD. C, The experiment was performed as stated in A, with the exception that noradrenaline as substrate and 1 μm tetrabenazine (TBZ) were used to specifically block VMAT2. Gαo2 (10 nm final concentration) was applied in the AlF4−-activated form, and the incubation was stopped after 10 min (*,**p < 0.003, p< 0.002, respectively). Values represent the mean of three individual culture wells ± SD. In the experiments given in A,values were calculated referring to the mean protein content of all samples.