Fig. 1.

Differential sensitivity of dopaminergic neurons in neuron-enriched and mixed neuron/glia mesencephalic cultures to rotenone-induced degeneration. A, B, Primary neuron-enriched or neuron/glia cultures were treated for 8 d with the vehicle (control group) or 1–30 nm rotenone; degeneration of dopaminergic neurons was evaluated with the [³H]DA uptake assay (A) or quantification of TH-IR neurons in the cultures (B). C, Mixed neuron/glia cultures were treated for 2–8 d with the vehicle or 1–25 nmrotenone; the [³H]DA uptake was determined at the desired time points. The amount of DA uptake for the vehicle-treated neuron/glia cultures at the time of treatment and 8 d after treatment was 0.77 ± 0.04 and 0.65 ± 0.06 and for vehicle-treated neuron-enriched cultures was 0.81 ± 0.07 and 0.77 ± 0.08 pmol/min per well, respectively. The results for DA uptake (A, C) and cell counts (B) are expressed as a percentage of the control cultures and are the mean ± SEM of four experiments performed in triplicate. *p < 0.01, compared with the control.