Chronic treatment with diisopropylfluorophosphate increases dopamine turnover in the striatum of the rat.

Following the administration of a single dose of diisopropylfluorophosphate (DFP) there is a rise of acetylcholine (ACh) in the rat striatum and frontal cortex. With chronic treatment, striatal ACh content returns to normal, but frontal cortex ACh remains elevated. In striatum but not frontal cortex, there is a rise of dopamine (DA) content and turnover after chronic DFP treatment. We speculate that DA content and turnover are increased after chronic DFP because the nigrostriatal neuronal feedback loop and local feedback loops are activated to compensate for increased cholinergic tone.