Microcirculation in the labyrinth

Abstract

The inner ear is unique in the number and variety of specialized microvascular networks that furnish blood to its parts. Four distinct capillary networks arranged in parallel supply the structures of the outer wall, and four others those of the spiral lamina. Most of the capillaries are surrounded by pericapillary spaces favoring filtration and reabsorption of fluid. In the guinea pig those of the spiral prominence and outer sulcus show a special pericapillary tissue. The strial capillaries are larger in diameter and are closely invested by strial cells. The blood within them has a higher hematocrit and flows more slowly than elsewhere in the labyrinth. The arcades of the tympanic lip and basilar membrane receive occasional innervation by fine unmyelinated nerve fibers. A possible role of prostaglandins in controlling the tone of the cochlear microvasculature is suggested. Although it appears unlikely that vascular lesions within the labyrinth could be responsible for the hydrops of Menière's syndrome, devascularization and atrophy of the endolymphatic sac might be contributory factors.

Immunocytochemical distribution of WARP (von Willebrand A domain-related protein) in the inner ear

“…The anatomy of inner ear microvessels has been studied using various techniques such as chemical staining with benzidine, vessel injection and electron microscopy (Axelsson, 1968; Mazzoni, 1990; Hawkins, 1976; Lawrence, 1980; Miller et al, 1995; Bachor et al, 2001). In the present study, WARP proves to be an effective and sensitive marker to delineate blood vessel vasculature in the mouse and human inner ear, adding sensitivity by colocalization with SMA-IR.…”

“…Among the suggested functions of WARP is its role in maintaining the blood-brain barrier (Allen et al, 2008). The inner ear is equipped with an intricate vasculature network (Axelsson, 1968; Bachor et al, 2001; Hawkins, 1976; Lawrence, 1980; Miller, 1995; Nakashima, 2003; Shi, 2009), as well as perivascular and perineural basement membrane proteins (Ishiyama et al, 2009). Thus in the present study we investigate the immunolocalization of WARP in the human and mouse inner ear.…”

Localization and Functional Studies of Pendrin in the Mouse Inner Ear Provide Insight About the Etiology of Deafness in Pendred Syndrome

“…The outer sulcus cells are situated in the lateral wall of the cochlear duct, between the spiral prominence cells adjacent to the stria vascularis and Claudius cells. Capillaries run between the outer sulcus cells and their roots, and it is thought that these cells transport endolymph electrolytes from the cochlear duct to the capillaries (Hawkins 1976). Outer sulcus cells serve to mediate the regulation of sodium and potassium levels in endolymph Marcus 2000, 2001;Marcus and Chiba 1999), although many details of how this is accomplished remain to be determined.…”

Photochemically induced focal cochlear lesions in the guinea pig: I. DAB staining and SEM study

“…Whether such sensory cells degeneration is caused by the lesion in the stria vascularis, by capillary lesion in the modiolar side system, or by both, should be further clarified in future work. So far the importance of the modiolar side capillaries has only been speculated upon (Hawkins, 1976). At present we are examining lesions localized only in the lateral wall in order to clarify the mechanism responsible for cochlear hair cell damage.…”