The effect of hemicholinium-3 and physostigmine on choline in rat brain

Physostigmine and hemicholinium-3 were examined for their effects on rat brain choline levels after microwave irradiation and after postmortem incubation. Hemicholinium-3 and physostigmine increased choline levels in the cerebellum and striatum when measured after microwave irradiation, but decreased the level of choline produced after postmortem incubation of the brain areas. Addition of the drugs in vitro to whole brain homogenates also decreased postmortem choline production. The data shows that the effect of hemicholinium-3 and physostigmine on in vivo choline levels can be differentiated from their effects on the postmortem production of choline, suggesting that the drugs are affecting at least two of the regulatory processes for choline in the brain.