From animal experiments by Cohen and Suzuki et al. in the 1960s to the first-in-human clinical trials now in progress, prosthetic electrical stimulation targeting semicircular canal branches of the vestibular nerve has proven effective at driving directionally appropriate vestibulo-ocular reflex eye movements, postural responses, and perception. That work was considerably facilitated by the fact that all hair cells and primary afferent neurons in each canal have the same directional sensitivity to head rotation, the three canals' ampullary nerves are geometrically distinct from one another, and electrically evoked three-dimensional (3D) canal-ocular reflex responses approximate a simple vector sum of linearly independent components representing relative excitation of each of the three canals. In contrast, selective prosthetic stimulation of the utricle and saccule has been difficult to achieve, because hair cells and afferents with many different directional sensitivities are densely packed in those endorgans and the relationship between 3D otolith-ocular reflex responses and the natural and/or prosthetic stimuli that elicit them is more complex. As a result, controversy exists regarding whether selective, controllable stimulation of electrically evoked otolith-ocular reflexes (eeOOR) is possible. Using micromachined, planar arrays of electrodes implanted in the labyrinth, we quantified 3D, binocular eeOOR responses to prosthetic electrical stimulation targeting the utricle, saccule, and semicircular canals of alert chinchillas. Stimuli delivered via near-bipolar electrode pairs near the maculae elicited sustained ocular countertilt responses that grew reliably with pulse rate and pulse amplitude, varied in direction according to which stimulating electrode was employed, and exhibited temporal dynamics consistent with responses expected for isolated macular stimulation. As the second in a pair of papers on Binocular 3D Otolith-Ocular Reflexes, this paper describes new planar electrode arrays and vestibular prosthesis architecture designed to target the three semicircular canals and the utricle and saccule. With this technological advancement, electrically evoked otolith-ocular reflexes due to stimulation via utricle- and saccule-targeted electrodes were recorded in chinchillas. Results demonstrate advances toward achieving selective stimulation of the utricle and saccule.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985858PMC
http://dx.doi.org/10.1152/jn.00883.2018DOI Listing

Publication Analysis

Top Keywords

utricle saccule
20
otolith-ocular reflexes
16
prosthetic electrical
12
electrical stimulation
12
stimulation targeting
12
electrically evoked
12
binocular otolith-ocular
8
stimulation
8
targeting utricle
8
hair cells
8

Similar Publications

Hypoxia tolerance and its variation with temperature, activity, and body mass, are critical ecophysiological traits through which climate impacts marine ectotherms. To date, experimental determination of these traits is limited to a small subset of modern species. We leverage the close coupling of carbon and oxygen in animal metabolism to mechanistically relate these traits to the carbon isotopes in fish otoliths (δC).

View Article and Find Full Text PDF

Association of vertigo with adult obstructive sleep apnea: A systematic review and meta-analysis.

Sleep Med

December 2024

Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Center of Sleep Disorder, National Taiwan University Hospital, Taipei, Taiwan; Department of Otolaryngology, College of Medicine, National Taiwan University, Taipei, Taiwan. Electronic address:

Background: Several studies have demonstrated a relationship between vertigo and obstructive sleep apnea (OSA) in adults. This review examined the association between vertigo and OSA and investigated the effects of OSA treatment on vestibular function.

Methods: Searches were conducted in PubMed, MEDLINE, EMBASE, Cochrane, Scopus, and Web of Science databases.

View Article and Find Full Text PDF

Divergent otolithic systems in the inner ear of Paranthropus robustus and Australopithecus africanus.

J Hum Evol

December 2024

Division of Anthropology, American Museum of Natural History, New York, NY, USA; Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Barcelona, Spain; New York Consortium in Evolutionary Primatology, New York, NY, USA.

The bony labyrinth of the inner ear houses the sensory end-organs responsible for balance (otolithic system in the utricle and saccule, and semicircular canal system) and hearing (cochlea). Study of the bony labyrinth has revealed considerable morphological diversity in the hominin lineage (semicircular canals and cochleae) and aided in reconstructing essential aspects of primate evolution, including positional behavior, audition, and phylogenic affinities. However, evidence of evolutionary change in the hominin otolithic system remains elusive.

View Article and Find Full Text PDF

A gene cadre orchestrates the normal development of sensory and non-sensory cells in the inner ear, segregating the cochlea with a distinct tonotopic sound frequency map, similar brain projection, and five vestibular end-organs. However, the role of genes driving the ear development is largely unknown. Here, we show double deletion of the Iroquois homeobox 3 and 5 transcription factors (Irx3/5 DKO) leads to the fusion of the saccule and the cochlear base.

View Article and Find Full Text PDF

Objectives: To compare the performance and optimal combination of MRI descriptors used for the diagnosis of Ménière's disease (MD) between a real-IR sequence with "zero-point" endolymph (ZPE), and an optimised real-IR sequence with negative signal endolymph (NSE).

Materials And Methods: This retrospective single-centre cross-sectional study evaluated delayed post-gadolinium ZPE and NSE real-IR MRI in consecutive patients with Ménièriform symptoms (8/2020-10/2023). Two observers assessed 14 MRI descriptors.

View Article and Find Full Text PDF

Want 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!