Depletion of brain norepinephrine with DSP-4 does not alter acquisition or performance of a radial-arm maze task

The acquisition of a radial-arm-maze task was unimpaired following administration of DSP-4, a selective noradrenergic neurotoxin. Maze performance remained unaffected when 5- or 30-min delays were imposed between the fourth and the fifth arm selection. Neurochemical analysis performed 90 days after injection revealed that DSP-4 significantly decreased concentrations of norepinephrine in the hippocampus, cortex, and cerebellum. The regional concentrations of dopamine and serotonin were not affected. These data are consistent with previous reports demonstrating that depletion of brain norepinephrine does not impair spatial learning and memory.