The sympathetic dependence of neuropathic pain is related to the upregulation of adrenergic receptors on primary afferent fibers and that these adrenergic receptors mediate the enhanced sensitivity of sensory fibers. We have found that norepinephrine transporter (NET) mRNA and protein of both dorsal root ganglia (DRG) and sympathetic ganglia are changed in L5/L6 spinal nerve ligation rats (Zheng et al, SFN 2002). To examine the relationships between sympathetic and sensory nerves, we evaluated the effect of sympathetic neurotransmitters on the expression and function of norepinephrine transporter in freshly dissociated DRG and celiac ganglia (CG) neurons. Freshly dissociated newborn rat DRG and CG neurons maintained in culture were incubated for 2 hr with the a1 agonist methoxamine, or the a2 agonist UK14304, or the purinergic agonist ab-methylene blue ATP. Real time PCR was used to analyze for NET mRNA and NET function was analyzed by measuring the uptake of the fluorescent probe ASP+ (4-(4-(dimethylamino...