Neurons in the locus coeruleus (LC) of monkeys show phasic activation following target stimuli during performance of a target detection task (Aston-Jones et al., 1994). These are not simply sensory or motor/premotor responses, but rather appear to be associated with decision about motivationally relevant stimuli (Clayton et al., SFN Abstr., 2003; Iba et al., this meeting). Our previous anatomical study revealed retrogradely labeled neurons in the orbitofrontal cortex (OFC) after tracer injection into the monkey LC, indicating that the OFC is a possible source for decision-motivation input to the LC (Aston-Jones et al., SFN Abstr., 2002). To further test this idea, we injected anterograde tracers (biotinylated dextran amine, BDA, 5%; fluorescein dextran, FD, 10%) into several sites of the OFC (mainly areas 12 and 13) of two African green monkeys. Staining for tracers and LC-noradrenergic neurons by immunohistochemistry showed prominent anterogradely labeled fibers and terminals among noradrenergic neurons a...