Diseases of the hearing organ and impairment affect a significant fraction of population. Therefore, the hearing organ embedded as a helical structure in the cochlea within the hardest human osseous structure inside the petrous bone is intensively investigated. Currently, studies of the cochlea with true micrometer resolution or better are destructive. Membranes and three-dimensional vessel str...

The molecular mechanisms dictating the morphogenesis and differentiation of the mammalian inner ear are largely unknown. To better elucidate the normal development of this organ, two approaches were taken. First, the membranous labyrinths of mouse inner ears ranging from 10.25 to 17 d postcoitum (dpc) were filled with paint to reveal their gross development. Particular attention was focused on ...

Connexin gap junctions play an important role in hearing function, but the mechanism by which this contribution occurs is unknown. Connexins in the cochlea are expressed only in supporting cells; no connexin expression occurs in auditory sensory hair cells. A gap junctional channel is formed by two hemichannels. Here, we show that connexin hemichannels in the cochlea can release ATP at levels t...

Astrocytes in the central nervous system (CNS) respond to injury and disease by proliferating and extending processes. The intermediate filament protein of astrocytes, glial fibrillary acidic protein (GFAP) also increases in astrocytes. These cells are called "reactive astrocytes" and are thought to play a role in CNS repair. We have previously demonstrated rapid increases (< 6 hours) in GFAP-i...

The adult mammalian cochlea receives dual afferent innervation: the inner sensory hair cells are innervated exclusively by type I spiral ganglion neurons (SGN), whereas the sensory outer hair cells are innervated by type II SGN. We have characterized the spatiotemporal reorganization of the dual afferent innervation pattern as it is established in the developing mouse cochlea. This reorganizati...

OBJECTIVE To determine the distribution of alpha1, alpha3, and alpha5 chains of type IV collagen in the cochlea in Alport syndrome. DESIGN Case-control study. PATIENTS Two patients with sensorineural hearing loss due to Alport syndrome. Both patients had known mutations in the COL4A5 gene. MAIN OUTCOME MEASURES Immunostaining was used to study the distribution of type IV collagen (alpha1,...

Organ development requires well-established intercellular communication to coordinate cell proliferations and differentiations. MicroRNAs (miRNAs) are small, non-coding RNAs that can broadly regulate gene expression and play a critical role in the organ development. In this study, we found that miRNAs could pass through gap junctions between native cochlear supporting cells to play a role in th...

The vertebrate planar cell polarity (PCP) pathway consists of conserved PCP and ciliary genes. During development, the PCP pathway regulates convergent extension (CE) and uniform orientation of sensory hair cells in the cochlea. It is not clear how these diverse morphogenetic processes are regulated by a common set of PCP genes. Here, we show that cellular contacts and geometry change drastical...

In the developing cochlea, Wnt/β-catenin signaling positively regulates the proliferation of precursors and promotes the formation of hair cells by up-regulating Atoh1 expression. Not much, however, is known about the regulation of Wnt/β-catenin activity in the cochlea. In multiple tissues, the activity of Wnt/β-catenin signaling is modulated by an interaction between LGR receptors and their li...

Conventional speech recognition systems require as input a sequence of acoustic vectors coding the relevant features of the speech signal. On the other hand the biological cochlea (inner ear) processes the speech signal to extract a neural coding suited for the higher levels of the brain. The background idea of this article is to interface an analogue electronic model of the cochlea with a stat...