Taipei, Feb. 7 (CNA) A research team from Taiwan's National Tsing Hua University has discovered why some animals can hear ultrasound while others cannot and further used ultrasound to activate the brain cells of laboratory mice suffering from Parkinson's disease, which subsequently led to improvements in their condition.
In a statement released by the university on Friday, the research team, headed by associate professor Lin Yu-chun (林玉俊), an expert in molecular medicine, and professor Yeh Chih-kuang (葉秩光) from the department of biomedical engineering, said it treated Parkinson's disease in mice by injecting soundwave sensitive protein into infected mice brains.
For many years Lin has searched for a "safe and non-invasive" way to "switch on" the activation of animal cells, the statement said, until he found that ultrasound does this better than light and magnetic waves, thanks to its ease of concentration and ability to penetrate more deeply.
Lin said all mammals have a protein called "prestin" in their bodies that plays a key role in hearing sensitivity.
However, in humans prestin barely reacts to ultrasound, Lin said, adding that he began studying why some animals, such as dolphins, whales and bats, can hear ultra-high frequency ultrasonic waves but others cannot.
Through gene mapping, he discovered the special amino acid combination in the prestin of ultrasound-sensitive animals. Subsequently, he genetically modified the prestin in mice and injected it into their cells.
Soon after the procedure he found that the sensitivity of the mice to sound waves increased more than 10-fold, according to Lin.
With Yeh's assistance, the research team designed a bubble system that carries the modified protein prestin to the infected brain through intravenous injection.
The "special bubbles" are then smashed by ultrasound to release the modified prestin which enable cells to "hear" the ultrasound and its instructions, Lin said.
Yeh said it is like the ultrasound "switches on" the activation of the cells enabling long-disconnected neurons to re-connect to each other.
A video shared by the research team shows a mouse suffering from Parkinson's disease stop half way along a wooden bridge, while mice that have undergone ultrasound therapy run across the bridge in less than three seconds.
The research showed that after being treated, the dopamine -- the organic chemical that functions both as a hormone and a neurotransmitter and plays several important roles in the brain and body -- in mouse brains significantly increases, according to the team.
This proves that the innovative therapy works in treating mice with Parkinson's disease, the research team said in the statement.
The research has turned ultrasound from a "passive" examination tool into an "active" medical treatment, Yeh touted, indicating that he expects their findings to be applied in curing diabetes by activating the cells that produce insulin.
The research was published on Dec. 29 in "Nano Letters," a monthly peer-reviewed scientific journal published by the American Chemical Society. The journal covers all aspects of nanoscience, nanotechnology and their sub-disciplines.