At an April 9th event sponsored by the Kavli Foundation and produced by Scientific American that honored Nobel and Kavli Prize winners, neuroscientists James Hudspeth and Robert Fettiplace talked about the physiology of hearing and the possibility of restoring hearing loss.
“It’s the truth for all of our senses that they are there to convert physical energy in the surrounding world into electrical responses, which are the common currency that the nervous system uses.”
Rockefeller University neuroscientist James Hudspeth.
“So our eyes and the photoreceptors there have to convert light into electricity. Our ears similarly have to convert mechanical vibrations in the air into electrical responses.
“And the way this is done is that there are so-called hair cells.... These cells have little microscopic bristles, about a hundred of them, and on the top of each cell these bristles vibrate back and forth in response to sound. That sets up an electrical signal that then goes down a nerve fiber and into the brain.”
Hudspeth, the University of Wisconsin–Madison’s Robert Fettiplace and the Pasteur Institute’s Christine Petit shared the 2018 Kavli Prize in Neuroscience for their work on the molecular and neural mechanisms of hearing. Hudspeth and Fettiplace both spoke April 9th at the National Academy of Sciences in Washington D.C. at an event honoring 10 U.S. Nobel and Kavli Prize Laureates. The evening was sponsored by the Kavli Foundation and produced by Scientific American. More from Hudspeth:
“And the real question is then is, what happens with these [hair cells] as they degenerate? We lose them owing to loud sounds, we lose them owing to certain legitimate drugs, we lose them just with aging. And what can be done to repair them so that we can restore hearing?”
"Well, I mean, there are two aspects to this: one is that in fact you could try and regrow them. Almost all hearing loss is due to death of the hair cells or lack of formation of them in the first place.... The cells along the cochlea are all different, and you’ve not got to just generate a generic hair cell, you’ve actually got to generate one that’s specific for each place, that has the specific properties which differ along the organ and will connect up to the nerve fibers."
“The problems that Robert has mentioned pertain to mammals, including ourselves. And the situation is very different with other four-legged animals, tetrapods. So in amphibians, in reptiles, including birds, this regeneration is going on all the time—same in fish. And in fact you can take a chicken to, you know, a Mötley Crüe concert or whatever, blast its ears, and they will quite nicely regenerate, even with frequency-specific hair cells, they will reconnect and the animal will be able to hear normally again.
“I agree that there is an enormous challenge, and this is certainly something that won’t happen overnight in ourselves. But I don’t think it’s a hopeless task and I think basically what many people are trying to do is to decode the signals that are sent as these hair cells develop, and by doing so to recognize the signaling pathways that might be reactivated to recapitulate the original development and restore hair cells by that means.”
Just don’t take your chicken to a Marilyn Manson concert.
(The above text is a transcript of this podcast)