Histofluorescence studies on the effect of 1,3-dimethyl-5-adamantanamine (D-145) on serotonin neurons in midbrain raphe nuclei.

1,3-Dimethyl-5-adamantanamine (D-145), a dopamine system stimulating agent, given at doses of 10-40 mg/kg ip, 2-5 hr before sacrifice, depressed the intensity of serotonin fluorescence in the rat midbrain raphe nuclei. Spiroperidol, 2 mg/kg ip, given 5 min before D-145, prevented the depression of serotonin fluorescence in the dorsal raphe nucleus (NDR), but not in the other groups of serotonin midbrain neurons. The results suggest a functional interaction between dopaminergic neurons and serotoninergic neurons in NDR.