Constitutive Neurogenesis in the Brain of Different Vertebrate Groups

Adult Neurogenesis of Teleost Fish Determines High Neuronal Plasticity and Regeneration

“…However, the unique regenerative profile of individual cell phenotypes in the diverse niches of brain stem cells remains unclear. Various types of neuronal precursors, as previously shown, are contained in sufficient numbers in different parts of the brain in juvenile Pacific salmon [10,19].…”

“…The multifold increase in the brain size of Pacific salmon is proportional to the enormous increase in their body length, which must be regulated by a highly differentiated central nervous system [10]. Chronically clarifying the mechanisms of the behavior of neuronal progenitors and/or NSCs after acute injury and changes in their activity may be a key to understanding the biology of different types of NSCs.…”

“…It is this feature of salmon that significantly distinguishes them from mammals, whose nervous tissue cells, after injury, produce an insufficient amount of these factors, which leads to the development of neuroinflammation [27]. It is also of interest that both markers are detected in cells of the proliferative periventricular zone (PVZ) of the salmon brain, which phenotypically correspond to NSPCs [10]. As a result of acute traumatic brain injury (TBI), the number of GS-and CBS-producing cells and the intensity of immunolabeling of these enzymes in these cells increases significantly, which indicates the direct involvement of these enzymes in the post-traumatic metabolism of NSPCs [14].…”

“…In contrast to mammalian models, the fish brain is considered to be a preferred vertebrate model for expanding our understanding of the cellular and molecular programs required for successful CNS regeneration [2,10]. In adult zebrafish, regeneration of the brain and spinal cord is driven by the presence of a variety of neural stem cells (NSCs) including, but not limited to, slowly and rapidly proliferating radial glia and neuroepithelial cells [11,12].…”

“…The study of different vertebrate models helps us to identify the unique characteristics of the central nervous system's structure, thus allowing us to take a new look at adult neurogenesis [13]. It is important to study neurogenesis not only in model organisms, but also in salmonids who, unlike the model organism Danio rerio are, as a member of the advanced teleost family, phylogenetically old representatives who retain plesiomorphic features in the development of their brains [10]. The phenomenon of fetalization-demonstrating the delay of signs of embryonic structure in juvenile and adult animals-has been known for a long time and is characteristic of sturgeon (cartilaginous ganoids) and salmon fish.…”