Chronic treatment with imipramine or mirtazapine antagonizes stress- and FG7142-induced increase in cortical norepinephrine output in freely moving rats.

The effect of repeated administration of imipramine or mirtazapine, two antidepressant drugs with different mechanisms of action, was studied on the stress-induced increase in the extracellular concentration of norepinephrine in the prefrontal cortex of freely moving rats. Exposure to footshock in control rats induced a marked increase in extracellular norepinephrine concentrations in the prefrontal cortex (+120%). Long-term administration with imipramine or mirtazapine (10 mg/kg, i.