In birds, singing behaviour is controlled by steroid hormones. Testosterone is essential for learning to sing but also in order to sing as an adult. Previous studies (1) have revealed brain structures controlling song in birds and the influence of testosterone and of the singing behaviour itself on the size of these structures. Professor Jacques Balthazart, from the GIGA Neurosciences at the University of Liege (Department of Biomedical and Preclinical Sciences / Biology of Sexual Differentiation), and his colleagues at the Johns Hopkins University (Baltimore MD, USA) have shown that in canaries, testosterone acts on different areas of the brain to control song and neurogenesis: it acts on the nucleus HVC to control the quality and structure of the song, and on the preoptic area to modulate the motivation to sing. In turn, singing induces an increase in neuroplasticity, i.e. the brain’s ability to restructure the connections between neurons and replace them. The hope is therefore to be able to transpose the mechanisms of plasticity observed in canaries to humans. "In the very long term”, Jacques Balthazart observes, “the idea is that if we manage to create neurogenesis or promote greater neurogenesis in the human brain, we will be able to counter, and even cure neurodegenerative diseases, or manage to repair, at least partly, traumatic brain damage". Read the article

(1) Beau A. Alward, Jacques Balthazart, and Gregory F. Ball, Differential effects of global versus local testosterone on singing behavior and its underlying neural substrate, PNAS Early Edition, Nov. 2013, www.pnas.org/cgi/ doi/10.1073/pnas.1311371110