Identification of different population of neural progenitor in adult pejerrey fish: Origin of proliferation, migration and cell fate.

STROBL MAZZULLA, P.H.; NÚÑEZ, A.; PELLEGRINI, E.; KAH, O.; SOMOZA, G.M.

Salvador

Congreso; Seventh International Congress of Comparative Physiology and Biochemistry,; 2007

Is well accepted that neurogenesis continues in subventricular zones of avian and mammalian adult brain. In these cases, the adult neural stem cells are astrocytes derived from embrionary radial glial cells. The brains of adult teleost fish are particular because they exhibit a high proliferative activity and strong aromatase expression, a key enzyme that converts androgens into estrogens, in persisting-radial glial cells. In pejerrey, proliferation zones were generally located in periventricular regions along the entire brain, similar to observed in other teleost. Double labeling failed to evidence a clearly generalized co-regionalization between aromatase-expressing radial glial cells and proliferative cells. However, a few cells in some regions clearly co-localized, principally in the ventral telencephalon (Vv). The cell fate of proliferative cells was analyzed by pulse chase BrdU-incorporation. After a 3-weeks chase, proliferative cells moved into the brain and were able to co-localize with neuronal and glial markers. After a 6-weeks chase, many cells have move away from their place of birth and others, such us in Vv, remained in the proliferative zone maintaining their proliferative capacity. We think that the migrating group of cells could act as progenitor and the second one, with label retention and self renewal capacity, as stem cells. Taking together, we have shown that proliferative cells in adult pejerrey brain have particular characteristics depending on the brain area. We considered that adult fish brain proliferation capacity should be analyzed as a particular process instead off a uniform one.