Early neurogenesis during caudal spinal cord regeneration in adult Gekko japonicus

Abstract

Gekko japonicus undergoes dramatic changes in the caudal spinal cord after tail amputation. The amputation induces cell proliferation in the caudal ependymal tube. We performed hematoxylin and eosin staining at different time points in the regeneration process to investigate the morphological characterization of the regenerated appendages. The central canal extended to the blastema post-amputation and the cartilage and muscle tissue appeared 3 weeks after injury. We performed the bromodeoxyuridine (BrdU) incorporation assay to detect proliferating cells during the regeneration process. BrdU positive cells were detected in the peri-central canal. Furthermore, nestin and neuron-specific enolase (NSE) immunocytochemistry were applied to detect neural stem/progenitor cells and neurons. Two weeks after injury, nestin-positive cells undergoing proliferation were located outside of the ependymal tube, and NSE positive cells appeared after 3 weeks of amputation. These data suggest that neurogenesis is an early event during caudal spinal cord regeneration in gecko.

Potential Involvement of Snail Members in Neuronal Survival and Astrocytic Migration during the Gecko Spinal Cord Regeneration

“…Gekko japonicus has a remarkable ability to regenerate amputated tail including major axial structures such as spinal cord, cartilage, muscles and spinal nerves, etc. (Wang et al, 2012; Zhou et al, 2013; Bai et al, 2015; Liu et al, 2015). The animal is becoming a new experimental model in the investigation of spinal cord regeneration (Szarek et al, 2016).…”

“…Survival of injured neurons is an indispensible strategy for successful spinal cord regeneration, along with neurogenesis (Lee-Liu et al, 2013; Zhou et al, 2013). Snail offers protection from both stress-induced cell death and that evoked by pro-apoptotic signals.…”

Ultrastructural immunolocalization of nestin in the regenerating tail of lizards shows its presence during cytoskeletal modifications in the epidermis, muscles and nerves

“…The presence of nestin in glial elongation might also explain the localization in ependymal cells and their endings terminating on the basement membrane (Simpson, 1968;Alibardi, 1990Alibardi, -1991Alibardi, , 2010b. Nestin has been previously detected in both ependymal cells and surrounding axons in the regenerating spinal cord of urodeles (Dawley et al, 2012) and lizards (Zhou et al, 2013;Alibardi, 2014b), where the proteins is likely utilized during axonal growth, cell division and expansion toward the tip of the regenerating tail.…”

“…From the proliferation of some ependymal cells few neurons are also generated inside the simplified spinal cord of the tail, suggesting that stem cell progenitors containing nestin are present (Alibardi, 2010a(Alibardi, , 2014aZhou et al, 2013). After the growth of the new tail slows down or stops, ependymal cells become differentiated as tanicytes (radial glia) and their lateral elongation converge toward the basement membrane to be stabilized against the pia meninge (Simpson, 1968;Alibardi, 1990Alibardi, -1991.…”

Special function of nestin + neurons in the medial septum-diagonal band of Broca in adult rats

“…Nestin is also expressed in reactive mature glial cells[1234]. The expression of nestin in these cells was associated with their differentiation or sustenance of their active state, and may be implicated in neurogenesis, remodeling and repair of the adult central nervous system[56789]. Although nestin always appears during particular periods of cell activation, the relationship between the expression of nestin and activation of cell specific function is not clear.…”