Electric-acoustic interactions in the hearing cochlea: single fiber recordings.

The present study investigates interactions of simultaneous electric and acoustic stimulation in single auditory nerve fibers in normal hearing cats. First, the auditory nerve was accessed with a microelectrode and response areas of single nerve fibers were determined for acoustic stimulation. Second, response thresholds to extracochlear sinusoidal electric stimulation using ball electrodes positioned at the round window were measured.

Inhibitory effect of N-acetyl cysteine and ascorbic acid on the development of myringosclerosis: an experimental study.

Objectives: This study investigated the effects of ascorbic acid and N-acetyl cysteine (NAC) antioxidants on the development of myringosclerosis (MS) in an experimental model.

Methods: Myringotomies were performed in the ears of 15 guinea pigs, and Spongostan pieces were placed on the perforated regions of the tympanic membrane. The subjects were divided randomly into three groups and treated with three different solutions on the Spongostan-group 1: (control, 0.

Nanosecond laser pulse stimulation of spiral ganglion neurons and model cells.

Optical stimulation of the inner ear has recently attracted attention, suggesting a higher frequency resolution compared to electrical cochlear implants due to its high spatial stimulation selectivity. Although the feasibility of the effect is shown in multiple in vivo experiments, the stimulation mechanism remains open to discussion. Here we investigate in single-cell measurements the reaction of spiral ganglion neurons and model cells to irradiation with a nanosecond-pulsed laser beam over a broad wavelength range from 420 nm up to 1950 nm using the patch clamp technique.

Quantitative analysis of neuronal response properties in primary and higher-order auditory cortical fields of awake house mice (Mus musculus).

Because of its great genetic potential, the mouse (Mus musculus) has become a popular model species for studies on hearing and sound processing along the auditory pathways. Here, we present the first comparative study on the representation of neuronal response parameters to tones in primary and higher-order auditory cortical fields of awake mice. We quantified 12 neuronal properties of tone processing in order to estimate similarities and differences of function between the fields, and to discuss how far auditory cortex (AC) function in the mouse is comparable to that in awake monkeys and cats.

α2δ3 is essential for normal structure and function of auditory nerve synapses and is a novel candidate for auditory processing disorders.

The auxiliary subunit α2δ3 modulates the expression and function of voltage-gated calcium channels. Here we show that α2δ3 mRNA is expressed in spiral ganglion neurons and auditory brainstem nuclei and that the protein is required for normal acoustic responses. Genetic deletion of α2δ3 led to impaired auditory processing, with reduced acoustic startle and distorted auditory brainstem responses.

Unilateral hearing during development: hemispheric specificity in plastic reorganizations.

The present study investigates the hemispheric contributions of neuronal reorganization following early single-sided hearing (unilateral deafness). The experiments were performed on ten cats from our colony of deaf white cats. Two were identified in early hearing screening as unilaterally congenitally deaf.

Expression analysis of ATAD3 isoforms in rodent and human cell lines and tissues.

ATAD3 (ATPase family AAA-Domain containing protein 3) is a mitochondrial inner membrane ATPase with unknown but vital functions. Initial researches have focused essentially on the major p66-ATAD3 isoform, but other proteins and mRNAs are described in the data banks. Using a set of anti-peptide antibodies and by the use of rodent and human cell lines and organs, we tried to detail ATAD3 gene expression profiles and to verify the existence of the various ATAD3 isoforms.

The effect of static force on round window stimulation with the direct acoustic cochlea stimulator.

The Direct Acoustic Cochlea Stimulator Partial Implant (DACS PI, Phonak Acoustic Implants SA, Switzerland) is intended to stimulate the cochlea by a conventional stapedotomy piston that is crimped onto the DACS PI artificial incus. An alternative approach to the round window (RW) is successfully done with other devices, having the advantage of being also independent of the existence of middle ear structure (e.g.

Nanosecond laser pulse stimulation of the inner ear-a wavelength study.

Optical stimulation of the inner ear, the cochlea, is discussed as a possible alternative to conventional cochlear implants with the hypothetical improvement of dynamic range and frequency resolution. In this study nanosecond-pulsed optical stimulation of the hearing and non-hearing inner ear is investigated in vivo over a wide range of optical wavelengths and at different beam delivery locations. Seven anaesthetized guinea pigs were optically stimulated before and after neomycin induced destruction of hair cells.

Developmental neuroplasticity after cochlear implantation.

Cortical development is dependent on stimulus-driven learning. The absence of sensory input from birth, as occurs in congenital deafness, affects normal growth and connectivity needed to form a functional sensory system, resulting in deficits in oral language learning. Cochlear implants bypass cochlear damage by directly stimulating the auditory nerve and brain, making it possible to avoid many of the deleterious effects of sensory deprivation.

Impaired stria vascularis integrity upon loss of E-cadherin in basal cells.

In the cochlea, sensory transduction depends on the endocochlear potential (EP) and the unique composition of the endolymph, both of which are maintained by a highly specialized epithelium at the cochlear lateral wall, the stria vascularis. The generation of the EP by the stria vascularis, in turn, relies on the insulation of an intrastrial extracellular compartment by epithelial basal cells. Despite the physiological importance of basal cells, their cellular origin and the molecular pathways that lead to their differentiation are unclear.

Smell and taste disorders.

Smell and taste disorders can markedly affect the quality of life. In recent years we have become much better in the assessment of the ability to smell and taste. In addition, information is now available to say something about the prognosis of individual patients.

Postintubation tracheal stenosis.

Postintubation tracheal stenoses are the result of an inadequate management of intubated patient. Consequence is different grade of respiratory insufficiency that leads to certain disability of patient. Surgical method of choice is segmental resection of trachea with "end-to-end" anastomosis.

Incidence of malignant tumors of larynx and their treatment.

We retrospectively analyzed patients with larynx cancer that were treated at ENT Clinics in Sarajevo in the last 5 years. According to the tumor site, TNM classification, operative procedure and postoperative treatment we found the following: Over the last 5 years 156 patients underwent surgical treatment--143 (91,6%) male and 23 (8.4%) female.

High-resolution image cytometry on smears of normal oral mucosa: a possible approach for the early detection of laryngopharyngeal cancers.

Background: The purpose of this study was to investigate the possibility of identifying laryngopharyngeal cancers by nuclear chromatin texture feature analysis of cell nuclei from mucosal scrapings obtained from clinically and cytologically noncancerous areas of the soft palate in patients with cancer.

Methods: The collective consisted of 68 controls and 77 cases of laryngopharyngeal carcinomas. After Feulgen staining, 3000 cell nuclei were automatically measured using a high-resolution image analyser (CytoSavant Oncometrics, Vancouver, BC, Canada).

Performance of normally hearing and hearing-impaired listeners using a German version of the SPIN test.

Various stages in the development of a German version of the English SPIN (Speech Performance in Noise) test have been reported previously by the authors (Züst & Tschopp, 1993). The test forms consist of 15 sentences each with a length of five to nine syllables. The forms have been constructed with either low predictable (LP) final words or high predictable (HP) final words, based upon the amount of contextual information available in the sentence.