Researchers find environmental toxins disruptive to hearing in mammals
Yale School of Medicine researchers have new data showing chloride ions are critical to hearing in mammals, which builds on previous research showing a chemical used to keep barnacles off boats might disrupt the balance of these ions in ear cells.
"Our data are the first to directly show that chloride ions are crucial for our exquisite sense of hearing," said Joseph Santos-Sacchi, professor in the Departments of Surgery and Neurobiology and first author of the study in the Journal of Neuroscience. "These data also indicate that the hearing in marine and other mammals could be affected by environmental toxins, such as TBT (tributyl tin), because they appear to alter the balance of chloride ions in the outer hair cell."
Sensitive hearing in mammals relies on cochlear amplification resulting from the motor activity of outer hair cells. They are the only group of animals that have outer hair cells. Additionally, TBT is known to damage the immune and hormonal systems of marine mammals.
In this study on guinea pigs, Santos-Sacchi tested whether TBT or salicylate, which is a chemical that occurs naturally in plants and is a component of aspirin, interfered with the guinea pigs’ ability to hear. He found that TBT, salicylate, or otherwise altering the extracellular chloride levels in the cochleas, interfered with the balance of chloride in the outer hair cells and caused profound changes in sound amplification in the inner ear.
In his previous study using TBT on isolated cells only, Santos-Sacchi had proposed that the ear’s ability to perceive sound would be compromised. He also speculated that whales and other marine mammals exposed to TBT would have altered sound localization abilities. The present findings confirm that their hearing is altered in mammals.
"Since many marine mammals use echolocation or sonar to get around, this could be contributing to whales and dolphins beaching and hitting ships," Santos-Sacchi said.
Jacqueline Weaver | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...