Adult Neurogenesis in Fish

Abstract

Teleost fish have a remarkable neurogenic and regenerative capacity in the adult throughout the rostrocaudal axis of the brain. The distribution of proliferation zones shows a remarkable conservation, even in distantly related teleost species, suggesting a common teleost ground plan of proliferation zones. There are different progenitor populations in the neurogenic niches-progenitors positive for radial glial markers (dorsal telencephalon, hypothalamus) and progenitors with neuroepithelial-like characteristics (ventral telencephalon, optic tectum, cerebellum). Definition of these progenitors has allowed studying their role in normal growth of the adult brain, but also when challenged following a lesion. From these studies, important roles have emerged for intrinsic mechanisms and extrinsic signals controlling the activation of adult neurogenesis that enable regeneration of the adult brain to occur, opening up new perspectives on rekindling regeneration also in the context of the mammalian brain.

Characterization of neurogenic niches in the telencephalon of juvenile and adult sharks

“…Adult neurogenesis has also been studied in the telencephalon of other non-mammalian species such as birds (Goldman and Nottebohm, 1983;Nordeen and Nordeen, 1988a, b;Álvarez-Buylla et al 1990Álvarez-Buylla et al , 19921998, Walton et al 2012Mazengenya et al 2018), reptiles (Pérez-Cañellas and García-Verdugo, 1996;Font et al 2001), amphibians (Simmons et al 2008;Kirkham et al 2014;Joven and Simon, 2018) and fish (Adolf et al 2006;Grandel et al 2006;Zupanc, 2006;März et al 2010;Quintana-Urzainqui et al 6 2015; reviewed by Ganz and Brand, 2016). Similarities between mammals and these groups have been found regarding the main types of cells found in the telencephalic neurogenic niche and the molecular markers they express.…”

“…Comparative studies have evidenced that the neurogenic capacity in the adult becomes more restricted to anterior regions of the brain throughout the course of vertebrate evolution. Fish are the group of vertebrates with the highest neurogenic potential, which has been linked to a continuous growth of the brain and with a high regenerative capacity (Alunni and Bally-Cuif, 2016;Ganz and Brand, 2016).…”

Comparative expression patterns of Sox2 and Sox19 genes in the forebrain of developing and adult turbot (Scophthalmus maximus)

“…SOX2 immunoreactive cells were found in the brain of developing and adult zebrafish in several periventricular areas considered as neurogenic zones (Adolf et al, 2006;German a et al, 2011;Grandel, Kaslin, Granz, Wenzel, & Brand, 2006;Lindsey, Darabie, & Tropepe, 2012;März et al, 2010;Pellegrini et al, 2007;Schmidt, Strähle, & Scholpp, 2013;Zupanc, Hinsch, & Gage, 2005). So, Sox2 appears involved in the maintenance of pluripotency and neurogenesis, which in teleosts occurs throughout life (reviewed in Chapouton, Jagasia, & Bally-Cuif, 2007;Ganz & Brand, 2016;Zupanc & Sîrbulescu, 2011).…”

“…The potential of the adult brain to generate new neurons is striking in teleosts, and new neurons are generated in numerous brain regions throughout adult life (reviewed in Chapouton et al, 2007;Ganz & Brand, 2016;Zupanc & Sîrbulescu, 2011). This neurogenic activity is linked to the persistence in the adult brain of radial glial cells acting as neural progenitors (Lam et al, 2009;März et al, 2010;Pellegrini et al, 2007).…”

Adult Neurogenesis: An Evolutionary Perspective

“…Work by Irmgard Amrein (2015) has provided an extensive update on the current information on how adult neurogenesis compares among mammalian species. Bergmann et al (2015), Ganz and Brand (2015), and Brenowitz and Larson (2015) dealt with fish, birds, and, as a special mammalian case, humans. Arguably, the consequences of adult neurogenesis for humans are the most critical aspect because, ultimately, it is the applications to the human situation that motivates a substantial part of the research dedicated to the new neurons.…”