Characterization of adult neurogenesis in lizardPhrynocephalus vlangalii(Agamidae: Reptilia)

Abstract

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 that the 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.

Food consumption increases cell proliferation in the python brain

“…The retrobulbar region, which has also been called the rostral forebrain, or anterior olfactory nucleus in lizards, is directly linked to the olfactory bulb (Halpern, 1980). This area shows high rates of neurogenesis in lizards (Delgado-González et al, 2008;Shao et al, 2012) and snakes (Bales, 2014), and is one of the most significant regions for neurogenesis in reptiles studied so far (Font et al, 2001). New cells may proliferate to migrate toward the olfactory bulbs for future processing, a mechanism resembling the rostral migratory stream (RMS) in mammals (Font et al, 2001;Lois and Alvarez-Buylla, 1994;Pérez-Cañellas and García-Verdugo, 1996).…”

Proliferation, Migration, and Survival of Cells in the Telencephalon of the Ball Python, Python Regius

“…The cells can then be observed with fluorescence or confocal microscopy to determine whether new cells are neurons or glia. Generalized surveys quantifying adult neurogenesis using confocal methods have been very limited in reptiles and no studies have used these techniques for surveys in snakes (Delgado-Gonzalez et al, 2011;Pérez-Cañellas and García-Verdugo, 1996;Sampedro et al, 2008;Shao et al, 2012).…”