July 7, 2009

Study looks at bird brain genetic activity

U.S. biologists say they've discovered unusual gene activity in the brains of zebra finches occurs after the birds hear a new song from another bird.

University of Illinois Professor David Clayton and his colleagues said they determined when a zebra finch hears a new song from a member of its own species, the experience affects thousand of genes, offering a new picture of memory in the songbird brain.

Clayton said the finding was a surprise since he hadn't expected to see so many genes involved, and thought any changes in gene activity after a bird heard a new song would quickly dissipate.

The experiments uncovered three distinct profiles of gene expression. One is typical of a bird sitting alone in silence. A second profile appears quickly just after a bird hears a recorded song -- but only if the song is new to the bird. A third profile emerges 24 hours later, after the song has become familiar.

In the study, each bird was kept in quiet isolation overnight before it heard a recording of a new song. The recording was then repeated every 10 seconds for up to three hours.

I can tell you whether the bird has heard a particular song before or not just by looking at the molecular assay, Clayton said.

The research is detailed in the June edition of the Proceedings of the National Academy of Sciences.