Parkinson''s disease is perhaps the most famous for its movement-related symptoms, particularly tremors and stiffness.
The disease is also known to hinder vocal production, giving those with Parkinson''s a soft, monotonous voice. These symptoms, according to research, often appear much earlier in the disease''s development sometimes decades before movement-related symptoms.
According to new research from neuroscientists from the University of Arizona, a particular gene commonly associated with Parkinson''s may be the basis for those vocal-related issues, a finding that might lead to earlier diagnosis and treatments for Parkinson''s patients.
In theCollege of Science,Julie E. Miller, an assistant professor of neuroscienceand ofspeech, language, and hearing sciences, was conducting research.
"We have this huge gap here we don''t know how this disease affects the brain regions for vocal production," Miller says of the program, which he has made several joint appointments and is now a member of the UArizonaBIO5 Institute.
Cesar Medina, a former UArizona undergraduate student who will soon attend theCollege of Medicine Tucson, andStephanie Munger, a research professional in the Department of Neuroscience, were also involved in the study.
A unique, professional speech evaluation tool.
The researchers applied to the zebra finch, a songbird native to Australia, to investigate the association between vocal changes and the Parkinson''s-related gene known as alpha-synuclein.
For several reasons, the birds are an ideal model for human speech and voice interactions, according to Medina. Young finches learn their songs from older, father-like male birds, in the same manner babies learn to speak through listening to their parents. A finch''s brain that handles speech and language is also structured very similar to its counterpart in the human brain.
"These similarities between behavior, anatomy, and genetics allow us to employ the zebra finches as a model for human speech and voice," Medina said.
Researchers first took baseline recordings of their songs to see how alpha-synuclein affect vocal production in the birds. They then introduced a copy of the gene into some of the birds, but other birds were not given the gene so researchers could compare them. All birds'' songs were then recorded once more after introducing the gene, and then one, two, and three months later.
Researchers used computer software to analyze and analyze the acoustic effects of the songs over time, by analysing the pitch, amplitude, and duration of the songs, to determine whether and when the vocal composition of the birds changed.
The first observations show that alpha-synuclein altered song production. After two months, birds with the gene sang less at the beginning of a song session three months after receiving the gene. The vocalizations were also less powerful and shorter, which is similar to those observed in the human disease.
Another step towards earlier diagnoses and treatments
Researchers searched for areas of Area X where the alpha-synuclein protein was found, aiding them to establish that the gene actually caused the changes in the brain that impacted vocal production. According to Medina, the researchers concluded that they found that some of the genes in Area X were beneficial to the speech effect.
In previous Parkinson''s research, he claimed that this connection had been identified, but it was not clear.
Miller said the next step is developing a software that could provide additional insights that lead to better Parkinson''s diagnosis and treatment, even if a patient is diagnosed with a neurologist.
The Miller Lab''s long-term ambition, according to she, is to collaborate with other researchers and private businesses to develop therapies that target alpha-synuclein and other genes associated with Parkinson''s.
Doing so, Medina said, would result in "we might stop the progression of Parkinson''s disease before it becomes a detrimental obstacle to the patient''s quality of life."