Monoaminergic neurotransmitters in Alzheimer's disease. An HPLC study comparing presenile familial and sporadic senile cases

Norepinephrine, epinephrine, dopamine, serotonin and their major metabolites were measured in 20 regions of the left hemisphere in 4 presenile familial cases of Alzheimer-type dementia and 4 sporadic senile cases. Both groups were compared to values in normal brains obtained in our laboratory. Quantitative determination of the monoamines was performed by HPLC with electrochemical detection. The clinical diagnosis of Alzheimer-type dementia was confirmed by histological examination of the right hemisphere and brain stem. The serotonergic system was dramatically affected in the familial cases with very low or undetectable serotonin concentrations in most cortical and subcortical areas studied and an important cell loss in the nucleus raphe dorsalis, origin of the main ascending serotonergic system. In the senile demented patients the serotonergic deficit is less important but still clearly present. The noradrenergic, adrenergic and dopaminergic systems were less affected by the disease process in senile sporadic as well as in the presenile familial type of Alzheimer's disease.