Microglial PHOX is critical for sub-picomolar SN neuroprotection. PHOX+/+ and PHOX-/- mouse neuron-glia cultures were pretreated with vehicle or SN (10-14 M) for 30 min, followed by LPS treatment. Neurotoxicity was assessed by measuring DA uptake (A), TNF-α production (B) and intracelluar ROS (C), respectively. Results are expressed as % of the control culture (A and C) and as pg/ml (B), and represent the mean ± SE for 3 individual experiments performed in triplicate in each experiment. *P < 0.05 compared with LPS culture. # P < 0.05, ## P < 0.01 compared with the vehicle-treated control cultures.