Researchers studying the effects of alcohol on learning and the brain have found that the songs of zebra finches (Taeniopygia guttata) become blurry and disorganized when they consume alcohol. One scientist called this the bird's "husky bar voice."
According to New Scientist, scientists also discovered that adolescent birds given alcohol do not develop the complex songs and vocalizations necessary to attract a mate in adulthood, changes that appeared to be permanent, even when the alcohol was removed.
Christopher Olson of Oregon Health and Science University in Portland presented a paper this week at the Society of Neuroscientists in New Orleans, Louisiana, suggesting that his results have potential implications for understanding the adverse effects of binge drinking in adolescents. He chose zebra finches as his test subjects because their song patterns are among the most studied non-human communication in the animal kingdom.
A male zebra finch spends the early part of his life like a tiny "American Idol" contestant, composing and learning its unique song, a pattern of tones and vocalizations that will eventually attract a mate. Female zebra finches select males with the songs they find most appealing.
Adult zebra finches given a 6 percent solution of ethanol in their drinking water, which they consumed freely until their blood alcohol levels reached as high as .08 percent, the legal limit for driving in most states.
New Scientist reported, "The birds were also happy to sing while drunk. Using audio analysis software, the researchers determined the degree of 'white noise,' or disorganised sounds, in their songs. The drunk birds' songs were significantly more broken and disorganised. 'It's their husky bar voice,' says Olson."
The team then set out to test the effects of alcohol on young birds' song development. The young male offspring were given a 3 percent ethanol solution, beginning at 40 days of age and continuing for three months. Differences were apparent almost immediately.
Healthy young birds, said Olson, typically "babble" and experiment with different sounds and disordered noises, many of which are inspired by the songs of their fathers and brothers. The birds drinking spiked water experimented far less and ultimately settled on a simple song at about 55 days of age.
Ofer Tchernichovski at the City University of New York told New Scientist that this is the first experiment of its kind, that never before have scientists studied the effects of alcohol or drugs on such a well-understood learned behavior.
Olson theorizes that alcohol negatively affects the brain's plasticity, or structural and cognitive flexibility. Because of this, the birds aren't able to learn properly. Once a finch is fully grown, its ability to learn new songs is gone.
The Oregon team is continuing to monitor the finches to see if they have become dependent upon alcohol and whether or not the birds taken off alcohol will ever finish developing.
On Tuesday, another team at the Society of Neuroscientists conference, this one led by National Institute of Health (NIH) child psychiatrist Jay Giedd, said that adolescent brains are particularly malleable and vulnerable. Adolescence, said Giedd, is a time of "great opportunity" for the brain to learn and develop, but also a time of great peril, when drugs, alcohol and head trauma can do serious, permanent damage.
[Photo of zebra finches via Shutterstock]