Neurotransmitter enzyme activities in neurons purified by bulk-isolation

Neurons, purified by bulk-isolation procedures from 10 day-old rat brain, are 80-90% homogeneous. Contaminants are primarily blood vessels and occasional oligodendroglia. All sizes and shapes of neurons are obtained, as they are isolated from all areas of the brain, except the cerebellum. Neurotransmitter enzyme activities involved in the metabolism of catecholamines, acetylcholine, and GABA are found at twice the level in these purified neurons when compared to that found in whole brain tissue. However, acetycholinesterase is found at a similar activity as in whole brain tissue, suggesting its localization in other cell types as well. Thus purified rat neurons are a good model system for studying neuronal function.