Track topics on Twitter Track topics that are important to you
: One limitation with cochlear implants is the difficulty stimulating spatially discrete spiral ganglion cell groups because of electrode interactions. Multipolar electrodes have improved on this some, but also at the cost of much higher device power consumption. Recently, it has been shown that spatially selective stimulation of the auditory nerve is possible with a mid-infrared laser aimed at the spiral ganglion via the round window. However, these neurons must be driven at adequate rates for optical radiation to be useful in cochlear implants. We herein use single-fiber recordings to characterize the responses of auditory neurons to optical radiation. STUDY
: In vivo study using normal-hearing adult gerbils.
: Two diode lasers were used for stimulation of the auditory nerve. They operated between 1.844 μm and 1.873 μm, with pulse durations of 35 μs to 1,000 μs, and at repetition rates up to 1,000 pulses per second (pps). The laser outputs were coupled to a 200-μm-diameter optical fiber placed against the round window membrane and oriented toward the spiral ganglion. The auditory nerve was exposed through a craniotomy, and recordings were taken from single fibers during acoustic and laser stimulation.
: Action potentials occurred 2.5 ms to 4.0 ms after the laser pulse. The latency jitter was up to 3 ms. Maximum rates of discharge averaged 97 ± 52.5 action potentials per second. The neurons did not strictly respond to the laser at stimulation rates over 100 pps.
: Auditory neurons can be stimulated by a laser beam passing through the round window membrane and driven at rates sufficient for useful auditory information. Optical stimulation and electrical stimulation have different characteristics; which could be selectively exploited in future cochlear implants. Laryngoscope, 2010.
Department of Surgery, ENT Section, Walter Reed Army Medical Center, Washington, DC.
This article was published in the following journal.
Name: The Laryngoscope
Lasers have recently become very useful for epiduroscopy. As the use of lasers increases, the potential for unwanted complications with direct application of laser energy to nerve tissue has also incr...
Single-crystal YAG (Y3Al5O12) fibers have been grown by the laser heated pedestal growth technique with losses as low as 0.3 dB/m at 1.06 μm. These YAG fibers are as long as about 60 cm with diameter...
Most studies on peripheral nerve injury have focused on repair at the site of injury, but very few have examined the effects of repair strategies on the more proximal neuronal cell bodies. In this stu...
Highly Tm(3+) doped optical fibers are urgently desirable for 2.0 μm compact single-frequency fiber laser and high-repetition-rate mode-locked fiber laser. Here, we systematically investigated the ...
The frontal nerve is characterized by its great content of sympathetic nerve fibers in contrast to cutaneous branches of the maxillary and mandibular nerves. However, we needed to add information abou...
The purpose of the study is to determine whether a particular type of nerve fibers, A-delta fibers, can be tested in an Electromyography (EMG) lab on a routine basis. Normal, healthy volun...
The goal of this study is to investigate the influence of transcutaneous vagus nerve stimulation 1. on the noradrenergic system in the brain and 2. on memory, in healthy volunteers. ...
The purpose of this study is to evaluate the defecatory function when nerve fibers around the inferior mesenteric artery(IMA) and left colic artery(LCA) are preserved(so called low ligatio...
Transcranial magnetic stimulation (TMS) involves the use of magnetic fields to non-invasively stimulate the brain. Studies overseas have suggested this may be an effective and safe treatme...
This study evaluates the ability of compensatory auditory stimulation (CAS) and transcranial direct current stimulation (tDCS) to help alleviate tinnitus. Subjects will receive CAS, tDCS, ...
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the unmyelinated nerve fibers are small. The axons to SCHWANN CELLS ratio is greater in the unmyelinated nerve fibers than that in the myelinated fiber (NERVE FIBERS, MYELINATED) which is 1:1. Usually several axons are surrounded by a single Schwann cell in the unmyelinated nerve fibers. Therefore, each unmyelinated fiber is not completely covered by the MYELIN SHEATH formed by the Schwann cell. Unmyelinated nerve fibers conduct impulses at low velocities. They represent the majority of peripheral sensory and autonomic fibers. They are also found in the spinal cord and brain.
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.
The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.
The nerve husk. The outermost part of the MYELIN SHEATH covering a myelinated nerve fiber (NERVE FIBERS, MYELINATED) or a bundle of unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED).
Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the central nervous system.
Hearing, auditory perception, or audition is the ability to perceive sound by detecting vibrations, changes in the pressure of the surrounding medium through time, through an organ such as the ear. Sound may be heard through solid, liquid, or gaseous mat...