Testosterone controls specific features of birdsong in two distinct regions of the canary brain that resemble the human motor cortex, according to a study published in The Journal of Neuroscience. The research points to a role for sex hormones in the regulation of this complex behavior that is more precise than merely increasing motivation to sing.
Canaries form a new song in the fall that becomes stable during the spring breeding season, when testosterone levels are high. This process parallels vocal development in humans, which begins with babbling in the first months of life and stabilizes after puberty.
Beau Alward and colleagues investigated the effects of testosterone on birdsong by blocking its receptors in two key brain regions involved in singing. Using male canaries, the authors found that the robust nucleus of the arcopallium (RA) regulates the production of song units such as syllables and trills (rapid repetition of a particular syllable type), while HVC regulates syntactical features such as how often a syllable type is used and the duration of trills. These results suggest that testosterone contributes to the canary's ability to learn a new song each year.
Article: Dissociable effects on birdsong of androgen signaling in cortex-like brain regions of canaries
Corresponding author: Beau Alward (Arnold O. Beckman Postdoctoral Fellow, Stanford University, Stanford, CA, USA), firstname.lastname@example.org
The Journal of Neuroscience (JNeurosci) is the flagship journal of the Society for Neuroscience. JNeurosci publishes papers on a broad range of topics in neuroscience in a print edition each Wednesday and recently began publishing early-release PDFs of studies online shortly after acceptance.
About The Society for Neuroscience
The Society for Neuroscience is the world's largest organization of scientists and physicians devoted to understanding the brain and nervous system. The nonprofit organization, founded in 1969, now has nearly 37,000 members in more than 90 countries and over 130 chapters worldwide.