New Mechanism for Super Song Learning in Zebra Finches Uncovered

Most songbirds learn their trills and melodies from their fathers. How well they learn these songs, though, is another matter entirely. Now, scientists have discovered a possible mechanism that is responsible for the differences in the intensity of song learning in zebra finches. The findings could allow researchers to better understand the processes behind learned behaviors in birds and may, in turn, provide insight into human learning.

The improvement of cognitive abilities plays an important role in the therapy of neurological and psychiatric diseases. In this case, the researchers examined the Brain Derived Neurotrophic Factor (BDNF) in zebra finches. BDNF is mainly responsible for the preservation, growth and differentiation of nerve cells. In experiments with mice, scientists have found that BDNF also enhances the ability to solve complex cognitive tasks.

In this experiment, the researchers examined learning in zebra finches. More specifically, they looked at zebra finch brother pairs that grew up with their genetic parents. In this particular setup, the juvenile birds learned songs readily from their fathers. However, there were differences in the intensity of song learning among siblings of the same age; the worst learners, for example, only had a similarity of 20 percent with their fathers' songs.

In order to see if BDNF was one of the causes for these differences, the researchers enhanced the expression of BDNF in the song control system in the brain for one brother while the other brother didn't get the same treatment. The scientists then analyzed the songs and found that birds that received more BDNF had a higher similarity with the song of their fathers compared with their "normal" brothers.

In fact, the learning efficiency in the BDNF-treated birds was as high as had been previously observed in the best learners within the nest. Scientists believe that was mainly due to an earlier onset of syllable copying in BDNF-treated birds.

The findings could allow researchers to understand a bit more about the learning process. Finding out about BDNF could be useful for treatments in humans in the future.

The findings are published in the European Journal of Neuroscience.