The Impact of Song Presentation on Songbirds’ Gene Expression Leads to Behavioural
Monday January 28 , 2013 The Impact of Song Presentation on Songbirds’ Gene Expression Leads to
In the study “Song Presentation Induces Gene Expression in the Songbird
Forebrain”, researchers attempted to answer the following question, “Are genomic
regulatory events part of the brain’s response to birdsong?” (Mello, Vicario, and Clayton,
1992). By observing whether or not there was a rapid response of Zenk expression in the
songbirds’ brains, researchers were able to collect information on these regulatory events.
Ultimately, the answer to this question is important in understanding animal behaviour as
it allows researchers to examine whether modification at the molecular level can lead to
changes in behaviour after exposure to birdsong. It can also help determine the pathways,
which are used to relay information to the song-selective areas in the brains of songbirds.
According to Mello et al. (1992), if genomic regulatory events do in fact play a role in the
brain’s response to birdsong exposure, then there should be a significant increase in Zenk
mRNA levels in the birds exposed to birdsongs.
In order to test their hypothesis, researchers conducted an experiment in which
two species, zebra finches and canaries, of male adult songbirds were isolated and
exposed to song stimulus of either conspecific birdsong, heterospecific birdsong, or non-
song stimulus (tone bursts). The stimulus was presented at the same time, distance and
sound intensity to avoid any variability amongst the test subjects. Songbirds who weren’t
exposed to any auditory stimulus were used as a control group. Afterwards, the birds
were sacrificed and their brains underwent hybridization and exposure to x-rays. The
Zenk cDNA was then isolated and brain sections of both species were analyzed using
brain imaging techniques (Mello et al., 1992). This experiment allowed researchers to observe high levels of Z