Recent research conducted on songbirds by biology and biochemistry assistant professor Preethi Gunaratne may benefit those suffering from speech impairments, learning disabilities and inhibitions in forming social connections.
Gunaratne played a major role in the larger research team that has set out to examine the zebra finch, which its study shows may have auditory learning capabilities that are comparable to humans.
Just as humans have the capacity to access memories of their infancy after decades, the zebra finch, or Taeniopygia guttata, uses this same model in its early development, later helping it to choose a mating partner and to set important social boundaries. They do this by memorizing and retaining song information from their parents.
“Interestingly, although both males and females are able to differentiate between different song types, the ability to learn and copy a particular song type that is specific to the family lineage is passed down only through the males,” Gunaratne said in a release.
“Young males learn and copy the song that is vocalized by their father, and this song learning must be accomplished during early infancy. After learning the song of their father, the sons are able to vocalize the specific song of their father very accurately. Therefore, the songbird has much to offer in relation to our efforts to understand the role of learning and memory in acquired human speech.”
The research team, led by Wesley Warren from the Genome Sequencing Center at Washington University in St. Louis and David Clayton from the University of Illinois at Urbana-Champaign, has published its findings thus far in a paper entitled “The Genome of the Zebra Finch: Special Insights into Vocal Learning and Communication,” which appeared in the April 1 issue of the journal Nature.
In studying the zebra finch’s auditory forebrain — the part of the brain that processes vocal learning — researchers discovered evidence that this unique ability stems from a large number of RNAs, molecules that transmit genetic information that were formerly thought to be useless. This is due to a recent paradigm shift that Gunaratne explained in the news release as “where small non-coding RNAs, called microRNAs, have emerged as important regulatory molecules that can diminish the levels of hundreds of genes that cooperate to form a network that supports a specific biological process.”
In order to test this ability in songbirds, researchers compared the animals’ brain activity when a song was being played to when the birds were experiencing silence. Evidence gathered from this experiment indicated that activity in the auditory forebrain during these contrasting conditions was completely different.
“When the young bird hears the father’s song a second time, a new set of microRNAs that can potentially support song learning are expressed and now act to potentially clear gene transcripts that cooperate to support the brain function under silent conditions,” Gunaratne said. “Basically, because a single microRNA can concurrently diminish the levels of hundreds of genes, they allow major shifts in gene networks to happen when we go from one situation to another.”
The Illumina Next Generation Sequencing instrument, which was acquired in 2008 for the Institute for Molecular Design at UH, was of integral contribution to the experiment, Gunaratne said. This cutting edge technology has also by Texas Medical Center faculty.
