HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 93/5/2777    most recent 01002.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (22) Citing Articles via Google Scholar Google Scholar Articles by Hullar, T. E. Articles by Minor, L. B. Search for Related Content PubMed PubMed Citation Articles by Hullar, T. E. Articles by Minor, L. B.

Responses of Irregularly Discharging Chinchilla Semicircular Canal Vestibular-Nerve Afferents During High-Frequency Head Rotations

¹Department of Otolaryngology—Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland; and ²Department of Otolaryngology—Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri

Submitted 23 September 2004; accepted in final form 7 December 2004

Mammalian vestibular-nerve afferents innervating the semicircular canals have been divided into groups according to their discharge regularity, gain at 2-Hz rotational stimulation, and morphology. Low-gain irregular afferents terminate in calyx endings in the central crista, high-gain irregular afferents synapse more peripherally in dimorphic (bouton and calyx) endings, and regular afferents terminate in the peripheral zone as bouton-only and dimorphic endings. The response dynamics of these three groups have been described only up to 4 Hz in previous studies. Reported here are responses of chinchilla semicircular canal vestibular-nerve afferents to rotational stimuli at frequencies up to 16 Hz. The sensitivity of all afferents increased with increasing frequency with the sensitivity of low-gain irregular afferents increasing the most and matching the high-gain irregular afferents at 16 Hz. All afferents increased their phase lead with respect to stimulus velocity at higher frequencies with the highest leads in low-gain irregular afferents and the lowest in regular afferents. No attenuation of sensitivity or shift in phase consistent with the presence of a high-frequency pole over the range tested was noted. Responses were best fit with a torsion-pendulum model combined with a lead operator (_HF1s + 1)(_HF2s + 1). The discharge regularity of individual afferents was correlated to the value of each afferent's lead operator time constants. These findings suggest that low-gain irregular afferents are well suited for encoding the onset of rapid head movements, a property that would be advantageous for initiation of reflexes with short latency such as the vestibulo-ocular reflex.

This article has been cited by other articles:

				S. G. Sadeghi, J. M. Goldberg, L. B. Minor, and K. E. Cullen Effects of Canal Plugging on the Vestibuloocular Reflex and Vestibular Nerve Discharge During Passive and Active Head Rotations J Neurophysiol, November 1, 2009; 102(5): 2693 - 2703. [Abstract] [Full Text] [PDF]

				S. G. Sadeghi, J. M. Goldberg, L. B. Minor, and K. E. Cullen Efferent-Mediated Responses in Vestibular Nerve Afferents of the Alert Macaque J Neurophysiol, February 1, 2009; 101(2): 988 - 1001. [Abstract] [Full Text] [PDF]

				A. Yang and T. E. Hullar Relationship of Semicircular Canal Size to Vestibular-Nerve Afferent Sensitivity in Mammals J Neurophysiol, December 1, 2007; 98(6): 3197 - 3205. [Abstract] [Full Text] [PDF]

				J. C. Holt, S. Chatlani, A. Lysakowski, and J. M. Goldberg Quantal and Nonquantal Transmission in Calyx-Bearing Fibers of the Turtle Posterior Crista J Neurophysiol, September 1, 2007; 98(3): 1083 - 1101. [Abstract] [Full Text] [PDF]

				S. G. Sadeghi, L. B. Minor, and K. E. Cullen Response of Vestibular-Nerve Afferents to Active and Passive Rotations Under Normal Conditions and After Unilateral Labyrinthectomy J Neurophysiol, February 1, 2007; 97(2): 1503 - 1514. [Abstract] [Full Text] [PDF]

				S. G. Sadeghi, M. J. Chacron, M. C. Taylor, and K. E. Cullen Neural Variability, Detection Thresholds, and Information Transmission in the Vestibular System J. Neurosci., January 24, 2007; 27(4): 771 - 781. [Abstract] [Full Text] [PDF]

				A. Haque, D. Huss, and J. D. Dickman Afferent Innervation Patterns of the Pigeon Horizontal Crista Ampullaris J Neurophysiol, December 1, 2006; 96(6): 3293 - 3304. [Abstract] [Full Text] [PDF]

				J. R. Risner and J. R. Holt Heterogeneous Potassium Conductances Contribute to the Diverse Firing Properties of Postnatal Mouse Vestibular Ganglion Neurons J Neurophysiol, November 1, 2006; 96(5): 2364 - 2376. [Abstract] [Full Text] [PDF]

				R. Ramachandran and S. G. Lisberger Transformation of Vestibular Signals Into Motor Commands in the Vestibuloocular Reflex Pathways of Monkeys J Neurophysiol, September 1, 2006; 96(3): 1061 - 1074. [Abstract] [Full Text] [PDF]

				S. T. Aw, M. J. Todd, and G. M. Halmagyi Latency and Initiation of the Human Vestibuloocular Reflex to Pulsed Galvanic Stimulation J Neurophysiol, August 1, 2006; 96(2): 925 - 930. [Abstract] [Full Text] [PDF]