Optical stimulation of the cochlea with laser light has been suggested as an alternative to conventional treatment of sensorineural hearing loss with cochlear implants. The underlying mechanisms are controversially discussed: The stimulation can either be based on a direct excitation of neurons, or it is a result of an optoacoustic pressure wave acting on the basilar membrane. Animal studies comparing the intra-cochlear optical stimulation of hearing and deafened guinea pigs have indicated that the stimulation requires intact hair cells. Therefore, optoacoustic stimulation seems to be the underlying mechanism. The present study investigates optoacoustic characteristics using pulsed laser stimulation for in vivo experiments on hearing guinea pigs and pressure measurements in water. As a result, in vivo as well as pressure measurements showed corresponding signal shapes. The amplitude of the signal for both measurements depended on the absorption coefficient and on the maximum of the first time-derivative of laser pulse power (velocity of heat deposition). In conclusion, the pressure measurements directly demonstrated that laser light generates acoustic waves, with amplitudes suitable for stimulating the (partially) intact cochlea. These findings corroborate optoacoustic as the basic mechanism of optical intra-cochlear stimulation.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4908384 | PMC |
| http://dx.doi.org/10.1038/srep28141 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Physiological effects of nasal high flow therapy during exercise in patients with chronic obstructive pulmonary disease: A crossover randomised controlled trial.
Pulmonology
December 2025
Sorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France.
Background: Nasal high flow (NHF) has been proposed to sustain high intensity exercise in people with COPD, but we have a poor understanding of its physiological effects in this clinical setting.
Research Question: What is the effect of NHF during exercise on dynamic respiratory muscle function and activation, cardiorespiratory parameters, endurance capacity, dyspnoea and leg fatigue as compared to control intervention.
Study Design And Methods: Randomized single-blind crossover trial including COPD patients.
"Minimal-Advice" on Salt Intake: Results of a Multicentre Pilot Randomised Controlled Trial on Hypertensive Patients.
High Blood Press Cardiovasc Prev
January 2025
Department of Clinical Medicine and Surgery, ESH Excellence Center of Hypertension, "Federico II" University of Naples Medical School, Via S. Pansini, 5, 80131, Naples, Italy.
Introduction: A strong and well-known association exists between salt consumption, potassium intake, and cardiovascular diseases. MINISAL-SIIA results showed high salt and low potassium consumption in Italian hypertensive patients. In addition, a recent Italian survey showed that the degree of knowledge and behaviour about salt was directly interrelated, suggesting a key role of the educational approach.
View Article and Find Full Text PDFCostly traits in a dynamic world: trait responses to fine-scale varying environment differ according to selection pressures in a tropical lizard.
Evolution
January 2025
Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, 560012, India.
Under current climate change patterns, rapidly changing environments can impose strong selection on traits. Costly traits that require heavy investment and strongly affect fitness may be particularly vulnerable to such changes. Despite organisms experiencing dynamic environments, our knowledge of costly trait response is limited as longitudinal studies across generations are rare.
View Article and Find Full Text PDFAccuracy of two-compartment modelling of gas exchange with ventilation-perfusion mismatch in inhalational anesthesia.
Anesthesiology
January 2025
Department of Critical Care, Melbourne Medicine School, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria, Australia.
Background: Multi-compartment computer models of heterogeneity in alveolar ventilation-perfusion ratios (VA/Q scatter) across the lung explain the significant alveolar-arterial (A-a) partial pressure gradients and associated alveolar dead-space fractions (VDA/VA) seen in anesthetized patients for both carbon dioxide and for anesthetic gases of different blood solubilities. However, the accuracy of a simpler two-compartment model of VA/Q scatter to do this has not been tested or compared to calculations from the traditional Riley model with "ideal", unventilated (shunt) and unperfused (deadspace) compartments.
Methods: Measurements of gas partial pressures in inspired and expired gas and arterial and mixed venous blood from 29 patients undergoing inhalational general anesthesia for cardiac surgery was used to compare the accuracy of two simple models of VA/Q scatter and lung gas exchange in predicting measured alveolar and arterial partial pressure differences, and associated alveolar dead-space calculations for the modern anesthetic gases isoflurane, sevoflurane and desflurane.
Parsing reward sensitivity reveals distinct relationships with energy intake, metabolic markers, physical activity and fitness.
Acta Neuropsychiatr
January 2025
Division of Neuropsychopharmacology, Department of Chemistry, University of Tartu, Tartu, Tartumaa, Estonia.
Rewards are rewarding owing to their hedonic or metabolic value. Individual differences in sensitivity to rewards are predictive of mental health problems but may reflect variation in metabolic types. We have assessed the association of two distinguishable aspects of reward sensitivity, openness to rewards (the striving towards multiple rewards) and insatiability by reward (the strong pursuit and fixation to a particular reward), with measures of metabolism and activity in a longitudinal study of representative birth cohort samples.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!