Neurogénese em mamíferos adultos - história de uma descoberta revolucionária e sua exploração no ensino das neurociências

Abstract

For many years, the mammalian brain was held as a static and immutable organ: "what you are born with, is all what you get" was the standing decree. It was not only until 1965, that Joseph Altman stepped into the first evidence of the birth of new neurons (neurogenesis) in the adult brain, using a newly developed technique to label these cells. Despite the initial impact of this work, it was eventually rejected by prominent neuroscientists at that time. Only in the 80s, was adult neurogenesis revisited and rediscovered, later to become one of the breakthroughs of the following decade, in the neurosciences field. The neurogenic process encompasses the birth, differentiation and integration of new functional neurons into pre-existing brain circuits. It is currently accepted to occur throughout life in the mammalian brain. These newly-born neurons originate from neural stem cells localized in restricted regions in the adult brain, namely in the subventricular zone (lining the brain ventricles), as well as in the dentate gyrus, within the hippocampus. Despite nowadays widely accepted, but still not exempted from debate, adult neurogenesis is a paradigmatic example of how sometimes science technical resources and theoretical decrees can sometimes hold back scientific progress. Indeed, the reason why adult neurogenesis found many barriers until its acceptance is grounded in different epistemological, conceptual and technical aspects. In light of the groundbreaking importance of neurogenesis, within the general concept of adult neuroplasticity, we will focus the following questions: "why was it so difficult to embrace the concept of adult neurogenesis in the field, and why in some aspects the debate is still on?"; "What implication has adult neurogenesis to education and application of neurosciences to the everyday reality that surrounds us? "