Inhibition of DA uptake by E
is regulated by cell density, and dose and time of E
treatment. Cells were serum-starved while being treated for 2 days with 20 ng/ml NGFβ. NET- and DAT-blocking drugs were included to define DAT-specific uptake. A. DA uptake inhibition by 10 nM E2 is robust at 10,000 and 15,000 cells/well, but reversed at densities as high as 20,000 cells/well. DAT-specific DA uptake was measured over a 30 min period ± E2 treatment during the last 5 minutes of the assay. * = significant difference between control and E2-treated samples at the level of p < 0.05. # = significant difference in DA uptake due to cell density conditions. B. All doses of E2 from 10-14 to 10-8 M caused inhibition of DA uptake, though with different levels of effectiveness, and in a nonconventional dose-response pattern. * = significant difference between control and E2-treated samples at the level of p < 0.05. C. The oscillating effects of 10 nM E2 on DA uptake at room temperature. Ethanol control background was subtracted from these values.