[Nootropic drugs and their action mechanisms in relation to the neuropathobiology of senile dementia. I. Neurotransmission disorders in the brain].

The author presents a review of agents which are presently included in the category of nootropic drugs and comments the relations between the pharmaceutical research of new nootropic and progressing knowledge of the neuropathobiology of Alzheimer's disease, senile dementia and degenerative processes of aging brain in general. In Part I., several hypotheses are discussed which explain the biological substrate of senile cognitive decline by disturbed brain synaptic neurotransmission (cholinergic, monoaminergic, petidergic) and, at the same time, drugs are suggested which may exert regulatory action on these dysfunctions.