Surface Microstructure of the Perilymphatic Space

Cochlear compound action potentials from high-level tone bursts originate from wide cochlear regions that are offset toward the most sensitive cochlear region

“…These results are consistent with the primary route of solution flow being along scala tympani. The results also clearly demonstrate that there is a communication between scala tympani, the spiral ganglion, and the AN in the modiolus, as was hypothesized for gerbil, cat, and human based on anatomic studies (Chole and Tinling 1994;Rask-Andersen et al 2006;Shepherd and Colreavy 2004). Despite this communication, we conclude that injected solution driven progressively along scala vestibuli is what produced our results, confirming the ability of the apical perfusion technique to show the spatial origin of CAPs.…”

“…The rates were chosen to be fast enough to overcome fluid losses from distribution to, and elimination from, the cochlea (Salt and Plontke 2009). However, porosities along the modiolar wall of scala tympani, found in both animals and humans (Chole and Tinling 1994;Schuknecht and Seifi 1963;Shepherd and Colreavy 2004), might be a route for fluid exchange between the perilymph ducts and the modiolus (Rask-Andersen et al 2006). We experimentally determined whether our results might be confounded by apically injected solutions reaching the cochlear base by flowing through such porosities and traveling down the modiolus, thereby reaching the base faster than by the normal flow of the perfusion along scala tympani.…”

Modulation of Mcl-1 expression reduces age-related cochlear degeneration

“…The fluorescence first appeared in supporting cells that directly contact the basilar membrane. This distribution pattern suggests that the route taken by the Lipofectamine-Mcl-1/pEGFP plasmid complex to the sensory cells passes from the canaliculi on the osseous spiral lamina to the basal domain of the supporting cells and then to the sensory cells, consistent with the route proposed by Shepherd and coworkers (Shepherd and Colreavy, 2004). Moreover, our functional and morphological data demonstrated that the transfection was relatively safe, with no significant influence on ABR thresholds or sensory cell viability.…”

Osteoprotegerin in the Inner Ear May Inhibit Bone Remodeling in the Otic Capsule

“…Our own morphologic studies and those of others showed an extensive system of interconnected canaliculi in the bone of the otic capsule that has direct openings into the labyrinthine spaces without an intervening barrier membrane 26 . The absence of a limiting membrane or endosteum in some areas between the perilymph and the bone of the cochlea was noted by Chole and Tinling 27 on electron microscopy.…”

“…7,[23][24][25] Our own morphologic studies and those of others showed an extensive system of interconnected canaliculi in the bone of the otic capsule that has direct openings into the labyrinthine spaces without an intervening barrier membrane. 26 The absence of a limiting membrane or endosteum in some areas between the perilymph and the bone of the cochlea was noted by Chole and Tinling 27 on electron microscopy. Additional evidence that this lacunocanalicular system permits the diffusion of small molecules from the perilymph into the otic capsule comes from experiments involving injection of horseradish peroxide (HRP) into the perilymph (Fig.…”