Flies Exposed to Loud Noises Suffer from "Hearing Loss"

Ridiculous, but true.  Flies and humans are not that different when it comes to hearing loss.

Photo credit: justcola from morguefile.com

Daniel Eberl, researcher at The University of Iowa says “We found that fruit flies exhibit acoustic trauma effects resembling those found in vertebrates, including inducing metabolic stress in sensory cells."

The effect on the molecular underpinnings of the fruit fly's ear are the same as experienced by humans, making the tests generally applicable to people, the researchers note.


So, how were the tests conducted?

The fly uses its antenna as its ear, which resonates in response to courtship songs generated by wing vibration.The researchers exposed a test group of flies to a loud, 120 decibel tone that lies in the center of a fruit fly's range of sounds it can hear. This over-stimulated their auditory system, similar to exposure at a rock concert or to a jack hammer. Later, the flies’ hearing was tested by playing a series of song pulses at a naturalistic volume, and measuring the physiological response by inserting tiny electrodes into their antennae. The fruit flies receiving the loud tone were found to have their hearing impaired relative to the control group.
When the flies were tested again a week later, those exposed to noise had recovered normal hearing levels. In addition, when the structure of the flies’ ears was examined in detail, the researchers discovered that nerve cells of the noise-rattled flies showed signs that they had been exposed to stress, including altered shapes of the mitochondria, which are responsible for generating most of a cell’s energy supply. Flies with a mutation making them susceptible to stress not only showed more severe reductions in hearing ability and more prominent changes in mitochondria shape, they still had deficits in hearing 7 days later, when normal flies had recovered.

http://now.uiowa.edu/2013/08/flys-hearing