Alterations in Catecholamine and Peptide Neurons in the Locus Coeruleus in Dementias of Alzheimer’s and Parkinson’s Disease

Abstract

A differentiation can be made between the locus coeruleus (LC) in normal brain, in Alzheimer’s disease (SDAT) and Parkinson’s disease (PD) for diagnostic purpose, based on the findings concerning the morphological alterations of the tyrosine-hydroxylase-imnunoreactive neurons, the topographical distribution of neuron loss within the length of the LC, and, to some extent, the total reduction in cell number. A reduction of total neuron numbers of the LC of up to 87.5% as compared to age-matched controls is found in SDAT. In PD cases, the neuronal morphology is generally more severely altered than in SDAT cases. The neuron loss is more severe than in SDAT (up to 94.4%). Simultaneously there is an increase in peptide containing neurons (galanin and neuropeptide Y) in SDAT compared to normal controls. The consequences of these findings will be discussed.