The Anatomy of Hearing and Balance Disorders and their Treatment: Welcome to a Brave New World


  • Jeffrey T. Laitman

    Corresponding author
    1. Center for Anatomy and Functional Morphology, Box 1007, Mount Sinai School of Medicine, New York, 10029
    • Center for Anatomy and Functional Morphology, Box 1007 Mount Sinai School of Medicine, New York, New York
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If New York City was a part our body, what do you think the city would be (careful here, I'm a native New Yorker and I have friends who know people…)? While some may say the cerebral cortex (for obvious reasons) or the heart (ditto) or larynx (as some of us are known to talk a lot), I would vote for the temporal bone. For those of you whose world does not go much beyond the molecular level (poor souls!), let me give a little background. The temporal bone in humans lies at the side and bottom of our skull. Its name “temporal” arises from the Latin, temporalis meaning “of time.” A thought is that the bone received its name as its flat, or squamosal portion, on the side of the head is where the passage of time is first seen (i.e., where we begin to grey).

While the side of our head may be fascinating to barbers and their ilk, the really alluring part of this bone lies largely on the bottom of the skull and is called the “petrous” (from the Greek, petra meaning “rock”) part of the temporal bone or petrous bone. It is, indeed, “rock-hard,” although not “rock-solid.” What lies within is why I see it as the equivalent of my beloved city. The realm is extraordinary because the crucial structures—hair cells, canals, nerves, bones, ligaments, membranes, fluids, vasculature, etc.—involved in two of our key senses, balance and hearing, reside within. The realm is one of the most congested and complex—like the streets of New York!—part of our anatomy and inherent physiology. And like little old New York, these parts have their own distinct evolutionary histories. They have migrated, morphed, and changed over the millennia, arising from differing areas in our ancestors to now co-habitat an incredibly congested and marvelously complex anatomical “melting pot.” From the “Outer” Ear (insulted daily with horrific piercings; do you think they evolved to hang ornaments from?!); to the “Middle” Ear with its ossicles and communications to the nasopharynx and portals to the respiratory system; to the “Inner” Ear, the sanctum of hearing and balance and one of the last largely unknown realms of mammalian biology. Indeed, the mysteries of our three “ears” continue to confound and yet fascinate anatomists, physiologists, geneticists, evolutionary biologists, and physicians. From the days of the Egyptians, to the nascent anatomists and biologists of the Renaissance, to today's leading investigators, the biology and diseases of our ears have riveted the best minds of science and medicine (see Laitman, 2006; Van De Water, 2012a.)

This Special Issue of The Anatomical Record, “The Anatomy and Biology of Hearing and Balance: Cochlear and Vestibular Implants,” is, most appropriately given the above, Guest Edited by Thomas Van De Water, who is as bone fide a New Yorker as it gets (Van De Water, 2012b). Indeed, his lineage hails from the pre-Revolutionary War Dutch inhabitants of New Amsterdam (i.e., my city before the English took it over and re-named it New York in 1665). If one looks on the old maps of New York, you can find in the upper tip of Manhattan, “Vandewaters farm.” Pretty impressive, to have your ancestral farm noted on a map of “Olde” New York. I had to pay to have my current address listed in our county phonebook!

Beyond his impressive pedigree (which, by the way, he proudly flaunts to us more “recent” 20th century arrivals), Van De Water is an extraordinary scientist of the cells, fluids, and neurobiology of the cochlear and vestibular worlds. He is also an historian of his science, a perch that has enabled him to view the fascinating attempts to decipher the anatomy, physiology and applications of such to one of the most central, yet poorly understood, realms of mammalian biology. Van De Water has also been an extraordinary teacher and mentor to scores in this field, myself included, by empowering our ability to pursue our science and our scientific advancements. Put these all together and you have a remarkable New Yorker with the inherent chutzpa and earned gravitas that empower him to enlist the best (and busiest!) minds in the cutting edge aspects of hearing and balance science to contribute to this extraordinary issue.

This Special Issue is unique in that it is The Anatomical Record's first truly “translational” issue. Its focus is not only upon new advances in basic biology—as is our trademark—but now incorporates the “cutting edge,” or soon to be cutting-edge, applications of the science. While some of our special issues in the past (e.g., Friedland, 2006 on the auditory system; Marquez, 2008 on paranasal sinuses) have included some important translational studies, this is the first full issue centering on translational, anatomically based, science. The combination herein of outstanding reviews and presentations of current research meld an appreciation of the history, anatomy, physiology, and genetics, with the development and application of prosthetic devices that attempt to augment and/or replace loss of hearing and balance. Indeed, today's understanding of hearing and balance is at the “Rubicon,” so to speak, of the field's involvement with science; leaving behind the “one day we will be able to …” phase to now cross boldly to the “we can” phase. Even for those of us, such as myself, familiar with aspects of the rapid advancements in the field, this assemblage of extraordinary basic biology with novel, translational, applications is awe-inspiring.

The papers in this special issue cover a range of topics relating to inner ear biology and the diseases/disorders/traumas that affect this world. All are diligently placed in evolutionary or developmental context, or often both, so that perspective is provided. Further, the integration of anatomy (the images and structural anatomy provided in some of the papers are elegant and will remind us of the fascination with structure that drew many of us to our studies), physiology, molecular approaches, genetics, and gene interventions is a masterful demonstration of the union of disciplines in modern biological research. Keeping with the translational focus, diseases or conditions described—be it hereditary deafness, ototoxicity, auditory cell loss, sensorimotor deficits, compromised Vestibulocochlear (CNVIII) function, trauma, implant-related trauma, or brainstem dysfunction to mention but a few—are but the starting point from which often groundbreaking interventions and implants are offered. I defy anyone to read these papers and not utter a “wow” a number of times. Simply put, the power of modern integrative anatomy in a translational world is demonstrated by the studies in this issue.

Some weeks back I went to a New York Yankees baseball game (actually, not that far from old “Vandewaters farm”) to enjoy watching them thoroughly thrash some pathetic wanna-be that came to town (so we're clear, there's the Yankees and there's everybody else.) I noticed three things: (1) hot dogs cost a lot more than when I was a kid; (2) I was less sure-footed than ever going up the steep steps (I was never a gazelle, but any nimbleness I had is surely going fast); and (3) I had to ask my neighbor a number of times “what did he say?” when announcements were made. While wisdom may come with getting “longer-in-the-tooth,” the subtle diminishment of our senses – particularly core ones such as hearing and balance – is unnerving at best. While the extraordinary science and bold translational interventions put forward in this special issue will hopefully start to address many of the truly debilitating diseases and pathologies of hearing and balance that affect so many, hopefully some of it will soon be applicable for a few of us old Yankee fans. I surely hope so.