Our results demonstrate the utility of using 3D cell shape features to characterize, compare, and classify cells in a living, developing organism.
Mathematical Analysis of Zebrafish Cell Shape Shows Connection With Cell Function
Driven by Data and Collaboration
The collaborative spirit of our Hearing Restoration Project consortium is especially evident as we work together to complete a publication describing our analysis of hair cell gene expression.
Inner Ear Cell Types Between Fish and Mammals Show Similarities
The similarities of inner ear cell type composition between fish and mammals validate the zebrafish as a relevant model for understanding inner ear-specific hair cell function and regeneration.
Elusive Cell Type in Fish Sensory Organs Discovered
Researchers from the Piotrowski Lab describe their discovery of the occasional occurrence of a pair of cells within post-embryonic and adult neuromasts that are not labeled by lateral line markers. When using a technique called Zebrabow, these cells are labeled a different color than the rest of the neuromast.
Study Explains ‘Cocktail Party Effect’ In Hearing Impairment
Commonly known as the “cocktail party effect,” people with hearing loss find it’s especially difficult to understand speech in a noisy environment. New research suggests that this may have less to do with actually discerning sounds. Instead, it may be a processing problem in which two ears blend different sounds together.
How Beautiful Hearing Loss Research Can Be
Hearing Health Foundation (HHF)’s scientists study sensory cells in various species to better understand how they are damaged and how they can be regenerated to restore human hearing. Here are five of the most breathtaking images from our scientists’ labs showcasing the beauty of the hearing and balance functions.
Looking to Other Sensory Organs to Better Understand Hair Cell Regeneration
In a Sept. 25, 2019, article published in the Annual Review of Cell and Developmental Biology, Hearing Restoration Project (HRP) consortium member Tatjana Piotrowski, Ph.D., and colleagues at the Stowers Institute for Medical Research in Missouri summarize the existing literature on hair cell regeneration in the context of sensory cell regeneration more broadly.
Size Control of the Inner Ear Through Fluid Pressure
In our paper published in the journal eLife on Oct. 1, 2019, we examined how this balloon grows into the more complex ear. Our work helped us formulate a new mathematical theory on how ear growth in animals is controlled.
Single-Cell RNA Sequencing Reveals More Clues for Hair Cell Regeneration
To study the genetic program of hair cell regeneration in zebrafish, we sequenced the RNA of individual cells within neuromasts, allowing us to classify cell types based on their gene expression signature.
Understanding a Pressure Relief Valve in the Inner Ear
By Ian Swinburne, Ph.D.
The inner ear senses sound to order to hear as well as sensing head movements in order to balance. Sounds or body movements create waves in the fluid within the ear. Specialized cells called hair cells, because of their thin hairlike projections, are submerged within this fluid. Hair cells bend in response to these waves, with channels that open in response to the bending. The makeup of the ear’s internal fluid is critical because as it flows through these channels its contents encode the information that becomes a biochemical and then a neural signal. The endolymphatic sac of the inner ear is thought to have important roles in stabilizing this fluid that is necessary for sensing sound and balance.
This study helps unravel how a valve in the inner ear's endolymphatic sac acts to relieve fluid pressure, one key to understanding disorders affected by pressure abnormalities such as Ménière’s disease.
While imaging transparent zebrafish, my team and I found a pressure-sensitive relief valve in the endolymphatic sac that periodically opens to release excess fluid, thus preventing the tearing of tissue. In our paper published in the journal eLife June 19, 2018, we describe how the relief valve is composed of physical barriers that open in response to pressure. The barriers consist of cells adhering to one another and thin overlapping cell projections that are continuously remodeling and periodically separating in response to pressure.
The unexpected discovery of a physical relief valve in the ear emphasizes the need for further study into how organs control fluid pressure, volume, flow, and ion homeostasis (balance of ions) in development and disease. It suggests a new mechanism underlying several hearing and balance disorders characterized by pressure abnormalities, including Ménière’s disease.
Here is a time-lapse video of the endolymphatic sac, with the sac labeled “pressure relief valve” at 0:40.
2017 Ménière’s Disease Grants scientist Ian A. Swinburne, Ph.D., is conducting research at Harvard Medical School. He was also a 2013 Emerging Research Grants recipient.