SECRETORY FORM OF BETA-AMYLOID PRECURSOR PROTEIN IS MUCH ABUNDANTLY CONTAINED IN THE CEREBRAL WHITE-MATTER IN HUMAN BRAIN

To elucidate the metabolic process of beta-amyloid precursor proteins (APP) in cerebral gray and white matter of the human brain, we compare d the content and characteristics of secretory APP between these two p arts. The white matter contained much more secretory APP than the gray matter in both a control and a Down's syndrome brain, but no differen ce in the characteristics of the APP isoforms was detected. Our result s suggest that, in the human brain, a considerable amount of APP is ca rried by axonal transport, during which some of the APP isoforms are p rocessed to their secretory forms.