Radial and Tangential Development of Neurons in the Human Cerebral Cortex-Immunohistochemistory of Ubiquitin Carboxyl Terminal (PGP9.5)-

Abstract

During the developmental period of the cortex, neurocyte cells are produced, differentiated in each area, then move in radial and tangential directions and form a layer structure. We immunohistochemically studied the expression of PGP9.5 (Ubiquitin-carboxyl terminus-enzyme) which was discovered as a unique protein substance in the neurocyte cells of the human cortex during the developmental period. The expression of PGP9.5 during development in humans increased in Cajal-Retzius cells in the external molecular layer at 13 weeks of gestation, then in the fifth layer pyramidal cells, the second and fourth layers granular cells, the third layer pyramidal cells and neurophils in that order, and decreased with advancing age. In cerebral white matter, PGP9.5 was increased in the deep layer around the same time as the molecular layer, then decreased with advancing age. The expression of cells positive for PGP9.5 increases with the healthy development of the human cortex, and it is thought that it reflects the growth and development of neurites and dendrites. Furthermore, from the fact that nerve stem cells develop after damage and show development of neurites and dendrites, they are thought to be an index of regeneration of neurites and dendrites as protein after damage.