Characterization of adult neurogenesis in lizard Phrynocephalus vlangalii (Agamidae: Reptilia)

摘要

Adult neurogenesis, a process of giving rise to neurons and glia from progenitors residing in restricted regions of the adult central nervous system (CNS) throughout life, varies considerably across species. The role of adult neurogenesis in reptiles,the amniotic vertebrates that possess spontaneous regenerative capacity is less known. In the present study, we used Phrynocephalus vlangalii - a typical reptile in northwest of China to investigate the cell proliferation and general pattern of glial fibrillary acidic protein (GFAP)-immunoreactivity in the brain of lizard. Compared with mammals, the brains of P. vlangaliiowned have simpler cytoarchitectonical patterns but a more widespread neurogenesis. Bromodeoxyuridine (BrdU)-labeled cells were mostly distributed in the ventricular zone of lateral ventricle with cell proliferation highest in the region referred to as anterior olfactory nucleus (AON). In addition, GFAP-immunostaining demonstrated differences in element, abundance and distribution. GFAP-positive cells were fundamentally represented by radial glial structures in telencephalon, diencephalon and mesencephalon. Furthermore, an intriguing finding was the emergence of GFAP-positive, star-shaped cells in the mesencephalon. We conclude thatthe cell proliferation and corresponding functions of glial lineage cells in lizards are closely implicated with phylogenetic development. Hence, reptiles provide excellent access for extracting core mechanisms of adult neurogenesis, which lays a good foundation to study the effect of different stimuli and exposure on the adult neurogenesis of reptiles.