QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted 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 (69) Citing Articles via Google Scholar Google Scholar Articles by Brozoski, T. J. Articles by Caspary, D. M. Search for Related Content PubMed PubMed Citation Articles by Brozoski, T. J. Articles by Caspary, D. M.

 Previous Article  |  Next Article 

The Journal of Neuroscience, March 15, 2002, 22(6):2383-2390

Elevated Fusiform Cell Activity in the Dorsal Cochlear Nucleus of Chinchillas with Psychophysical Evidence of Tinnitus

T. J. Brozoski¹, C. A. Bauer¹, and D. M. Caspary²

¹ Division of Otolaryngology, Head and Neck Surgery and ² Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702

Chinchillas with psychophysical evidence of chronic tinnitus were shown to have significantly elevated spontaneous activity and stimulus-evoked responses in putative fusiform cells of the dorsal cochlear nuclei (DCN). Chinchillas were psychophysically trained and tested before and after exposure to a traumatic unilateral 80 dB (sound pressure level) 4 kHz tone. Before exposure, two groups were matched in terms of auditory discrimination performance (noise, and 1, 4, 6, and 10 kHz tones). After exposure, a single psychophysical difference emerged between groups. The exposed group displayed enhanced discrimination of 1 kHz tones (p = 0.00027). Postexposure discrimination of other stimuli was unaffected. It was hypothesized that exposed animals experienced a chronic subjective tone (i.e., tinnitus), resulting from their trauma, and that features of this subjective tone were similar enough to 1 kHz to affect discrimination of 1 kHz objective signals. After psychophysical testing, single-unit recordings were obtained from each animal's DCN fusiform cell layer. Putative fusiform cells of exposed animals showed significantly (p = 0.0136) elevated spontaneous activity, compared with cells of unexposed animals. Putative fusiform cells of exposed animals showed a greater stimulus-evoked response to tones at 1 kHz (p = 0.0000006) and at characteristic-frequency (p = 0.0000009). This increased activity was more pronounced on the exposed side. No increase in stimulus-evoked responses was observed to other frequencies or noise. These parallel psychophysical and electrophysiological results are consistent with the hypothesis that chronic tonal tinnitus is associated with, and may result from, trauma-induced elevation of activity of DCN fusiform cells.

Key words: tinnitus; acoustic trauma; psychophysical animal model; dorsal cochlear nucleus; fusiform cells; neural plasticity

---

Copyright © 2002 Society for Neuroscience  0270-6474/02/2262383-08$05.00/0

This article has been cited by other articles:

				R. Schaette and R. Kempter Predicting Tinnitus Pitch From Patients' Audiograms With a Computational Model for the Development of Neuronal Hyperactivity J Neurophysiol, June 1, 2009; 101(6): 3042 - 3052. [Abstract] [Full Text] [PDF]

				Y. Zhao, M. E. Rubio, and T. Tzounopoulos Distinct Functional and Anatomical Architecture of the Endocannabinoid System in the Auditory Brainstem J Neurophysiol, May 1, 2009; 101(5): 2434 - 2446. [Abstract] [Full Text] [PDF]

				C. Zeng, N. Nannapaneni, J. Zhou, L. F. Hughes, and S. Shore Cochlear Damage Changes the Distribution of Vesicular Glutamate Transporters Associated with Auditory and Nonauditory Inputs to the Cochlear Nucleus J. Neurosci., April 1, 2009; 29(13): 4210 - 4217. [Abstract] [Full Text] [PDF]

				T. Tzounopoulos Mechanisms of Synaptic Plasticity in the Dorsal Cochlear Nucleus: Plasticity-Induced Changes That Could Underlie Tinnitus Am J Audiol, December 1, 2008; 17(2): S170 - S175. [Abstract] [Full Text] [PDF]

				J. A. Kaltenbach and D. A. Godfrey Dorsal Cochlear Nucleus Hyperactivity and Tinnitus: Are They Related? Am J Audiol, December 1, 2008; 17(2): S148 - S161. [Abstract] [Full Text] [PDF]

				J. G. Turner and J. Parrish Gap Detection Methods for Assessing Salicylate-Induced Tinnitus and Hyperacusis in Rats Am J Audiol, December 1, 2008; 17(2): S185 - S192. [Abstract] [Full Text] [PDF]

				R. Panford-Walsh, W. Singer, L. Ruttiger, S. Hadjab, J. Tan, H.-S. Geisler, U. Zimmermann, I. Kopschall, K. Rohbock, A. Vieljans, et al. Midazolam Reverses Salicylate-Induced Changes in Brain-Derived Neurotrophic Factor and Arg3.1 Expression: Implications for Tinnitus Perception and Auditory Plasticity Mol. Pharmacol., September 1, 2008; 74(3): 595 - 604. [Abstract] [Full Text] [PDF]

				D. M. Caspary, T. A. Schatteman, and L. F. Hughes Age-Related Changes in the Inhibitory Response Properties of Dorsal Cochlear Nucleus Output Neurons: Role of Inhibitory Inputs J. Neurosci., November 23, 2005; 25(47): 10952 - 10959. [Abstract] [Full Text] [PDF]

				N. Weisz, C. Wienbruch, K. Dohrmann, and T. Elbert Neuromagnetic indicators of auditory cortical reorganization of tinnitus Brain, November 1, 2005; 128(11): 2722 - 2731. [Abstract] [Full Text] [PDF]

				J. A. Kaltenbach, J. D. Rachel, T. A. Mathog, J. Zhang, P. R. Falzarano, and M. Lewandowski Cisplatin-Induced Hyperactivity in the Dorsal Cochlear Nucleus and Its Relation to Outer Hair Cell Loss: Relevance to Tinnitus J Neurophysiol, August 1, 2002; 88(2): 699 - 714. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help