The endolymphatic sac is an irregular, complicated shaped bag like structure in the inner ear. It is involved in absorbing and secreting, and it takes part in the immune response. Although not entirely clear, theories suggest that the endolymphatic sac is involved in the development of Meniere’s disease leading to dizziness and hearing problems. Current research is shedding some light on this mysterious biological component.
A couple of years back, a Harvard researcher found a mysterious structure in the inner ear of a zebrafish while conducting a time-lapse microscopy study. The structure inflated and deflated in a perfectly timed rhythm. The structure was the fluid-filled endolymphatic sac. Although this structure’s existence is well known, it’s function is not.
The key to understanding the secret of the endolymphatic sac was visualizing it at work. The researchers, in collaboration with various microscopy laboratories, pieced together a clear view of the sac and published their findings. According to the research, the endolymphatic sac serves as a pressure-relief valve that regulates the release of fluid from the inner ear. Scientists have long speculated that the endolymphatic sac plays a part in the regulation of pressure within the inner ear, but the mammalian ear is challenging to access and study. The inner ears of the zebrafish are much more accessible for study.
The inner ear is an interrelated network of structures filled with specialized fluid that moves as a response to sound waves and head movement. Detection of fluid motion by sensory cells takes place, followed by conversion into neural signals for processing in the brain. Specific disorders stem from problems involving this pressure fluctuation.
Meniere’s disease involves an excessive amount of inner ear fluid in the channels of the inner ear. When the amount of fluid increases, hearing loss is often the result. The condition and the accompanying dizziness, tinnitus, and pressure in the ear are incapacitating. This build-up of fluid can also cause vertigo which is a sensation of feeling off balance.
The findings can have a tremendous impact on the treatment of disorders involving defects in the inner ear. It seems that the endolymphatic sac is a mechanism for maintaining the fluid pressure within the inner ear. This knowledge can be beneficial in the treatment of Meniere’s disease and vertigo. It can also open the door for the study of other organs such as the eyes and kidneys which also posses fluid-filled cavities.
These results indicate that the endolymphatic sac is a pressure-relief valve for the inner ear. The team believes that this mechanism is present in other organs that contain a fluid such as an eye, brain, and kidneys. This research is undoubtedly shedding new light on the fluid present in the inner ear and hopefully may improve treatment for disorders such as Meniere’s disease and vertigo. The mystery of the endolymphatic sac is vanishing away.