Association with the cholinergic precursor choline alphoscerate and the cholinesterase inhibitor rivastigmine : An approach for enhancing cholinergic neurotransmissionH]hemicholinium-3 binding were assessed in rat frontal cortex, hippocampus and striatum. Acetylcholine immunoreactivity was also evaluated in cerebrocortical cholinergic fibers by immunohistochemistry. Choline alphoscerate or rivastigmine, but not choline increased acetylcholine levels as well as [H]hemicholinium-3 binding. Rivastigmine alone or in association with either choline or choline alphoscerate decreased acetylcholinesterase (AChE), whereas choline or choline alphoscerate alone did not affect AChE activity. Choline alphoscerate or rivastigmine alone or in association, but not choline increased acetylcholine immunoreactivity in nerve fibers supplying cerebral cortex. These data suggest that combination of a suitable precursor of brain acetylcholine such as choline alphoscerate and of a cholinesterase inhibitor may represent an association worthwhile of being further investigated as a cholinergic replacement therapy in pathologies characterized by altered cholinergic neurotransmission.