A golgi study of cell types in the dentate gyrus of the adult human brain.

1. The morphology of neurons in the dentate gyrus of the adult human brain was analyzed with two variants of Golgi technique. 2. About 20 neuronal types and subtypes were observed in the dentate gyrus of the adult human, several of which has not previously been described in the human. The human dentate gyrus harbors 4 types of neurons in the molecular layer, 3 types within the granule cell layer, and at least 10 types in the hilus. 3. Compared to the granule neurons in the rat brain, human granule neurons show a much greater variability. Many of these human neurons have basal dendrites and/or axonal spines. Also, there are significant differences among these neurons regarding the density of their dendritic trees and dendritic spines. In contrast to the rat, human hilar neurons with complex spines have complex spines not only on their dendrites but also on their cell bodies. 4. This study opens the door for further morphological studies involving specific diseases such as Alzheimer's disease and epilepsy.