Primary cultures of neuronal and non-neuronal rat brain cells secrete similar proportions of amyloid beta peptides ending at A beta40 and A beta42.

To determine the types of brain cells responsible for the production of amyloid beta peptides (A beta), as well as their carboxyl-terminal properties, we studied the secretion of A beta in rat neuronal, astrocytic, microglial and meningeal primary cell cultures. All four types of cells produced A beta, among which neurons secreted approximately 4 times more A beta than other cell types. The percentage of A beta42 ending at position 42 as a fraction of total A beta was similar between different cell types, ranging from 10 to 15%. These results suggest that neurons might be the most potent source for A beta production in the brain, although other non-neuronal type cells could also contribute to this process.