Topics include active biomechanics of sensory hair bundles, molecular composition of vestibular hair bundles, the tectorial
membrane, hair cell afferent synapses, efferent inhibition of the cochlea, inner ear connexin channels, the epidemiology of deafness, hidden hearing loss, and age-related hearing loss.
We have discovered that a tiny structure in the cochlea known as the tectorial
membrane plays an important role in this process, by acting as a storage depot for calcium ions.
Both the ear's sensitivity and its selectivity -- its ability to distinguish different frequencies of sound -- depend crucially on the behavior of a minuscule gelatinous structure in the inner ear called the tectorial
membrane, which Freeman and his students have been studying for more than a decade.
The trichomes that were found were of the unicellular tectorial
type, which presented great quantity (Figures 1E and 1G); therefore, the presence of trichome scars was frequent (Figures 1E-H and 1K).
(2) Figure la provides details of the CCJ and the associated anterior supporting structures, including the alar ligaments, the apical ligament tectorial
membrane, anterior atlanto-occipital and atlantoaxial membranes.
The current literature highlights injuries involving the transverse atlantal ligament , and tectorial
membrane injuries have been reported ; however, injuries to the posterior atlantoaxial ligament are not widely published.
Moreover, other structures (e.g., tectorial
membrane and Reissner's membrane) in the cochlea have also been suggested to be capable of supporting wave propagation inside the cochlea [21, 22], but their contribution to the cochlear mechanical dynamics has not been thoroughly studied and determined.
Cochlear exposure to intense sounds can cause excessive movement of the tectorial
membrane, resulting in loss of contact between the stereocilia on the hair cells and the tectorial
membrane, and separation of the tip links between stereocilia, leading to a disturbance in signal transduction [4, 5].
The hematoma was noted to overlay an intact, otherwise unremarkable tectorial
membrane and to extend distal to the membrane attachment at the dorsal mid C2 vertebral body, consistent with a subdural location (Figures 5,6).
The proposed pathophysiology includes paraesthesia of auditory nerve, vasospasm due to autonomic imbalance, irritation of tympanic plexus, hypersensitivity of chorda tympani nerve, sludging of blood, increased tension on inner ear fluids by middle ear muscles, intracellular oedema of the organ of Corti pushing hair cells to come into contact with the tectorial
Another anatomical change was detachment of the tectorial
membrane from outer hair cell stereocilia bundles (Figure 2).