Effects of physostigmine, paraoxon and soman on brain GABA level and metabolism

The effects of sublethal doses of physostigmine, paraoxon and soman on GABA levels and metabolism were studied in small rat brain areas (hypothalamus, striatum, cerebellum, rest of the brain). Physostigmine induced a significant decrease in striatal GABA level and a reduction of synthesis index in the rest of the brain while organophosphates have little or no effect on GABA level and metabolism. This work provides new data about the physostigmine effect on brain GABA which could be related to the action of the anticholinesterase agents on other non-cholinergic neurotransmitters.