Electrical Cochlear Stimulation in the Deaf Cat: Comparisons Between Psychophysical and Central Auditory Neuronal Thresholds

2000 ◽  
Vol 83 (4) ◽  
pp. 2145-2162 ◽  
Author(s):  
Ralph E. Beitel ◽  
Russell L. Snyder ◽  
Christoph E. Schreiner ◽  
Marcia W. Raggio ◽  
Patricia A. Leake
Keyword(s):  
Electrical Stimulation ◽  
Auditory System ◽  
Pulse Rate ◽  
Auditory Nerve ◽  
Round Window ◽  
Electrode Array ◽  
Scala Tympani ◽  
Behavioral Thresholds ◽  
Current Pulses ◽  
Stimulation Of

Cochlear prostheses for electrical stimulation of the auditory nerve (“electrical hearing”) can provide auditory capacity for profoundly deaf adults and children, including in many cases a restored ability to perceive speech without visual cues. A fundamental challenge in auditory neuroscience is to understand the neural and perceptual mechanisms that make rehabilitation of hearing possible in these deaf humans. We have developed a feline behavioral model that allows us to study behavioral and physiological variables in the same deaf animals. Cats deafened by injection of ototoxic antibiotics were implanted with either a monopolar round window electrode or a multichannel scala tympani electrode array. To evaluate the effects of perceptually significant electrical stimulation of the auditory nerve on the central auditory system, an animal was trained to avoid a mild electrocutaneous shock when biphasic current pulses (0.2 ms/phase) were delivered to its implanted cochlea. Psychophysical detection thresholds and electrical auditory brain stem response (EABR) thresholds were estimated in each cat. At the conclusion of behavioral testing, acute physiological experiments were conducted, and threshold responses were recorded for single neurons and multineuronal clusters in the central nucleus of the inferior colliculus (ICC) and the primary auditory cortex (A1). Behavioral and neurophysiological thresholds were evaluated with reference to cochlear histopathology in the same deaf cats. The results of the present study include: 1) in the cats implanted with a scala tympani electrode array, the lowest ICC and A1 neural thresholds were virtually identical to the behavioral thresholds for intracochlear bipolar stimulation; 2) behavioral thresholds were lower than ICC and A1 neural thresholds in each of the cats implanted with a monopolar round window electrode; 3) EABR thresholds were higher than behavioral thresholds in all of the cats (mean difference = 6.5 dB); and 4) the cumulative number of action potentials for a sample of ICC neurons increased monotonically as a function of the amplitude and the number of stimulating biphasic pulses. This physiological result suggests that the output from the ICC may be integrated spatially across neurons and temporally integrated across pulses when the auditory nerve array is stimulated with a train of biphasic current pulses. Because behavioral thresholds were lower and reaction times were faster at a pulse rate of 30 pps compared with a pulse rate of 2 pps, spatial-temporal integration in the central auditory system was presumably reflected in psychophysical performance.

Brain Stem Response Evoked by Electrical Stimulation of the round Window of the Guinea Pig

1981 ◽  
Vol 89 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Hitoshi Yamane ◽  
Roger R. Marsh ◽  
William P. Potsic
Keyword(s):  
Electrical Stimulation ◽  
Guinea Pig ◽  
Auditory Nerve ◽  
Round Window ◽  
Direct Electrical Stimulation ◽  
Output Function ◽  
Input Output ◽  
Nerve Excitability ◽  
Brain Stem Response ◽  
Stimulation Of

The wave that is believed to correspond to wave V in man is an appropriate indicator of auditory nerve excitability because it is not contaminated by nonauditory neurogenic responses to electrical stimulation. The responses to direct electrical stimulation of the auditory nerve could be distinguished from the electrophonic response by the steep input-output function and constant latency of the former. Myogenic responses are prominent unless a muscle relaxant is administered.

Relationship of acoustic stimulation and tinnitus suppression by electrical stimulation

1984 ◽  
Vol 98 (S9) ◽  
pp. 125-127
Author(s):  
A. Shulman
Keyword(s):  
Electrical Stimulation ◽  
Auditory System ◽  
Auditory Perception ◽  
Clinical Investigation ◽  
Round Window ◽  
Acoustic Stimulation ◽  
Auditory Stimulation ◽  
Sound Perception ◽  
Auditory Suppression ◽  
Stimulation Of

Electrical stimulation of the auditory system results in auditory perception as well as auditory suppression. Historically, this is well documented. The recent application of advances of high technology and microsurgery of the ear have allowed basic science and clinical investigation to have access to electrical stimulation of the auditory system and its response. It is historically of great interest that such investigation in the past always involved attempts for evaluation and treatment for either auditory stimulation and/or auditory suppression. I believe the work of Aran (1981) reawakened recent interest in electrical stimulation of the auditory system for tinnitus suppression as well as auditory stimulation. Briefly, in his investigation of a deaf patient, he observed the following: (a) negative currents were more effective than positive currents for auditory stimulation; (b) positive current pulses reduced (suppressed) the intensity of tinnitus; (c) electrical stimulation in deaf patients by negative currents resulted in some sound perception. (In the congenitally deaf patients, it is difficult to evaluate the sensation produced); (d) the intensity of positive pulses necessary to suppress tinnitus is always higher than that of negative pulses resulting in auditory perception; (e) for positive pulses, the range between the threshold of tinnitus suppression and auditory perception when pulses of intermediate intensity are used, without inducing auditory perception, is wide enough to achieve total tinnitus suppression. (In other words, the current effective for electrical stimulation suppressing tinnitus is at a strength well below that producing auditory sensation); (f) negative electrical pulses can produce two different sounds-tinnitus and an auditory sensation; (g) electrical stimulation via the promontory and/or round window can be used both for auditory stimulation as well as for auditory suppression.

Prosthetic Stimulation of the Auditory System with Intraneural Electrodes

2003 ◽  
Vol 112 (9_suppl) ◽  
pp. 20-25 ◽  
Author(s):  
H. Alexander Arts ◽  
Derek A. Jones ◽  
David J. Anderson
Keyword(s):  
Auditory System ◽  
Cochlear Nucleus ◽  
Auditory Nerve ◽  
Current Status ◽  
Practical Reasons ◽  
Scala Tympani ◽  
Electrode Arrays ◽  
Nucleus Surface ◽  
Recent Developments ◽  
Stimulation Of

Prosthetic electrical stimulation of the auditory system is presently accomplished either via scala tympani electrode arrays or via cochlear nucleus surface electrode arrays. Many of the early cochlear implant studies, however, used electrode arrays placed within the auditory nerve itself — either within the modiolus or within the trunk of the nerve. For many reasons, such intraneural electrode arrays were abandoned in favor of intrascalar arrays. There remain, however, several theoretical and practical reasons why intraneural arrays might be advantageous, and recent developments in electrode technology solve many of the problems posed by early attempts at intraneural stimulation. In this article, we review the history and current status of intraneural auditory stimulation, and present some preliminary results of this mode of stimulation in an animal model.

scholarly journals Changes in Prefrontal Cortex–Thalamic Circuitry after Acoustic Trauma

Biomedicines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 77
Author(s):  
Kristin M. Barry ◽  
Donald Robertson ◽  
Wilhelmina H. A. M. Mulders
Keyword(s):  
Electrical Stimulation ◽  
Prefrontal Cortex ◽  
Auditory System ◽  
Acoustic Trauma ◽  
Neuron Activity ◽  
Compensatory Mechanism ◽  
Efferent Connections ◽  
Medial Geniculate ◽  
Central Auditory Pathways ◽  
Stimulation Of

In the adult auditory system, loss of input resulting from peripheral deafferentation is well known to lead to plasticity in the central nervous system, manifested as reorganization of cortical maps and altered activity throughout the central auditory pathways. The auditory system also has strong afferent and efferent connections with cortico-limbic circuitry including the prefrontal cortex and the question arises whether this circuitry is also affected by loss of peripheral input. Recent studies in our laboratory showed that PFC activation can modulate activity of the auditory thalamus or medial geniculate nucleus (MGN) in normal hearing rats. In addition, we have shown in rats that cochlear trauma resulted in altered spontaneous burst firing in MGN. However, whether the PFC influence on MGN is changed after cochlear trauma is unknown. We investigated the effects of electrical stimulation of PFC on single neuron activity in the MGN in anaesthetized Wistar rats 2 weeks after acoustic trauma or sham surgery. Electrical stimulation of PFC showed a variety of effects in MGN neurons both in sham and acoustic trauma groups but inhibitory responses were significantly larger in the acoustic trauma animals. These results suggest an alteration in functional connectivity between PFC and MGN after cochlear trauma. This change may be a compensatory mechanism increasing sensory gating after the development of altered spontaneous activity in MGN, to prevent altered activity reaching the cortex and conscious perception.

Electrical stimulation of the auditory nerve: direct current measurement in vivo

1999 ◽  
Vol 46 (4) ◽  
pp. 461-469 ◽  
Author(s):  
C.Q. Huang ◽  
R.K. Shepherd ◽  
P.M. Center ◽  
P.M. Seligman ◽  
B. Tabor
Keyword(s):  
Electrical Stimulation ◽  
Direct Current ◽  
Auditory Nerve ◽  
Current Measurement ◽  
Direct Current Measurement ◽  
Stimulation Of

Electrically Evoked Brainstem Responses in Cochlear Implant Recipients

1987 ◽  
Vol 96 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Richard T. Miyamoto ◽  
D. Douglas Brown
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Auditory Nerve ◽  
Clinical Applications ◽  
Assessment Tools ◽  
Laboratory Setting ◽  
Recording Technique ◽  
Stimulus Artifact ◽  
Artifact Suppression ◽  
Stimulation Of

Electrical stimulation of the auditory nerve in the profoundly deaf population through implanted cochlear prostheses has increased the need for reliable electrophysiologic assessment tools. We have recorded electrically evoked brainstem responses (EABRs) in 21 subjects who have received a 3M/House cochlear implant. Recordings have been made, both intraoperatively and postoperatively, in the laboratory setting. The recording technique, methods of stimulus artifact suppression, and results of our measurements are described. Clinical applications of this technology are suggested.

scholarly journals Laminar Variation in Threshold for Detection of Electrical Excitation of Striate Cortex by Macaques

2005 ◽  
Vol 94 (5) ◽  
pp. 3443-3450 ◽  
Author(s):  
Edgar A. DeYoe ◽  
Jeffrey D. Lewine ◽  
Robert W. Doty
Keyword(s):  
Electrical Stimulation ◽  
Striate Cortex ◽  
Human Subjects ◽  
Human Case ◽  
Constant Current ◽  
Electrical Excitation ◽  
Detection Thresholds ◽  
Current Pulses ◽  
A Site ◽  
Stimulation Of

Macaques were trained to signal their detection of electrical stimulation applied by a movable microelectrode to perifoveal striate cortex. Trains of ≤100 cathodal, 0.2-ms, constant current pulses were delivered at 50 or 100 Hz. The minimum current that could be reliably detected was measured at successive depths along radial electrode penetrations through the cortex. The lowest detection thresholds were routinely encountered when the stimulation was applied to layer 3, particularly just at the juncture between layers 3 and 4A. On the average, there was a twofold variation in threshold along the penetrations, with the highest intracortical thresholds being in layers 4C and 6. Variations as high as 20-fold were obtained in some individual penetrations, whereas relatively little change was observed in others. The minimum detectable current was 1 μA at a site in layer 3, i.e., 10–100 times lower than that for surface stimulation. Because macaques, as do human subjects, find electrical stimulation of striate cortex to be highly similar at all loci (a phosphene in the human case), it is puzzling as to how such uniformity of effect evolves from the exceedingly intricate circuitry available to the effective stimuli. It is hypothesized that the stimulus captures the most excitable elements, which then suppress other functional moieties, producing only the luminance of the phosphene. Lowest thresholds presumably are encountered when the electrode lies among these excitable elements that can, with higher currents, be stimulated directly from some distance or indirectly by the horizontal bands of myelinated axons, the stria of Baillarger.

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