Sound starts as waves of mechanical vibrations that travel through the air to the ear by compressing air molecules. Upon reaching the cochlea of the inner ear, fluid pressure changes caused by sound vibration stimulate specialized hair cells to respond.
This contributes to mechanotransduction, the process by which cells convert mechanical stimuli into electrical signals to neurons in the brain, enabling us to hear.
Scientists from The Scripps Research Institute (TSRI) report on the action of harmonin, one of three known proteins involved in mechanotransduction. The study also reports, for the first time, how a molecular defect can impair the opening of ion channels on the tips of inner-ear hair cells resulting in deafness. The study is published in the journal Neuron.
Fluorescent proteins do more than glow
Researchers at Scripps Institution of Oceanography at UCSD and the Salk Institute for Biological Studies have discovered a family of green fluorescent proteins (GFPs) in a primitive sea animal, along with new clues about the role of the proteins that has nothing to do with their famous glow.
Using a range of genetic analyses and techniques, researchers discovered that some GFPs, especially those with low fluorescence capacity, could have a defense function in the wild acting as an antioxidant, working to protect the animal in times of illness or stress. It's the first evidence of the proteins being used in a role beyond glowing fluorescence. The discovery is described in the journal BioMed Central Evolutionary Biology.
Tone language is key to perfect pitch
Perfect or absolute pitch is defined as recognizing the pitch of a musical note without having to compare it to a reference note. The ability is rare in the U.S. and Europe, where only about one person in 10,000 is thought to have it. Musicians who speak an East Asian tone language fluently, however, are much more likely to have perfect pitch.
According to UCSD researcher Diana Deutsch, this ability probably is more the result of nurture than nature, more environment than genes, because many East Asian languages are "tonal," in which a word's meaning often depends on the tone in which it is said.
The finding suggests that perfect pitch might be available to virtually everyone, akin to learning a second language.
The study is published in the Journal of the Acoustical Society of America and was presented this month at the society's annual meeting.