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Wallace MN, Sumner CJ, Berger JI, McNaughton PA, Palmer AR. Salicylate decreases the spontaneous firing rate of guinea pig auditory nerve fibres. Neurosci Lett 2021; 747:135705. [PMID: 33548408 DOI: 10.1016/j.neulet.2021.135705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/26/2021] [Accepted: 01/29/2021] [Indexed: 02/03/2023]
Abstract
Spontaneous firing rates were recorded from single auditory fibres in vivo. Salicylate was injected at 350 mg/kg by the subcutaneous route. Median firing rate decreased by 32 spikes/s in nerve fibres after salicylate injection. The high spontaneous rate fibres (type 1A) showed the main reduction.
Tinnitus has similarities to chronic neuropathic pain where there are changes in the firing rate of different types of afferent neurons. We postulated that one possible cause of tinnitus is a change in the distribution of spontaneous firing rates in at least one type of afferent auditory nerve fibre in anaesthetised guinea pigs. In control animals there was a bimodal distribution of spontaneous rates, but the position of the second mode was different depending upon whether the fibres responded best to high (> 4 kHz) or low (≤4 kHz) frequency tonal stimulation. The simplest and most reliable way of inducing tinnitus in experimental animals is to administer a high dose of sodium salicylate. The distribution of the spontaneous firing rates was different when salicylate (350 mg/kg) was administered, even when the sample was matched for the distribution of characteristic frequencies in the control population. The proportion of medium spontaneous rate fibres (MSR, 1≤ spikes/s ≤20) increased while the proportion of the highest, high spontaneous firing rate fibres (HSR, > 80 spikes/s) decreased following salicylate. The median rate fell from 64.7 spikes/s (control) to 35.4 spikes/s (salicylate); a highly significant change (Kruskal-Wallis test p < 0.001). When the changes were compared with various models of statistical probability, the most accurate model was one where most HSR fibres decreased their firing rate by 32 spikes/s. Thus, we have shown a reduction in the firing rate of HSR fibres that may be related to tinnitus.
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Schillberg P, Brill S, Nikolay P, Ferger R, Gerhard M, Führ H, Wagner H. Sound localization in barn owls studied with manipulated head-related transfer functions: beyond broadband interaural time and level differences. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2020; 206:477-498. [PMID: 32140774 DOI: 10.1007/s00359-020-01410-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 02/06/2020] [Accepted: 02/13/2020] [Indexed: 10/24/2022]
Abstract
Interaural time and level differences are important cues for sound localization. We wondered whether the broadband information contained in these two cues could fully explain the behavior of barn owls and responses of midbrain neurons in these birds. To tackle this problem, we developed a novel approach based on head-related transfer functions. These filters contain the complete information present at the eardrum. We selected positions in space characterized by equal broadband interaural time and level differences. Stimulation from such positions provides reduced information to the owl. We show that barn owls are able to discriminate between such positions. In many cases, but not all, the owls may have used spectral components of interaural level differences that exceeded the known behavioral resolution and variability for discrimination. Alternatively, the birds may have used template matching. Likewise, neurons in the optic tectum of the barn owl, a nucleus involved in sensorimotor integration, contained more information than is available in the broadband interaural time and level differences. Thus, these data show that more information is available and used by barn owls for sound localization than carried by broadband interaural time and level differences.
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Affiliation(s)
- Patrick Schillberg
- Institute of Biology II, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Sandra Brill
- Institute of Biology II, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Petra Nikolay
- Institute of Biology II, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Roland Ferger
- Institute of Biology II, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany.,Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Maike Gerhard
- Lehrstuhl A für Mathematik, RWTH Aachen University, Templergraben 55, 52056, Aachen, Germany
| | - Hartmut Führ
- Lehrstuhl A für Mathematik, RWTH Aachen University, Templergraben 55, 52056, Aachen, Germany
| | - Hermann Wagner
- Institute of Biology II, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany.
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Naert G, Pasdelou MP, Le Prell CG. Use of the guinea pig in studies on the development and prevention of acquired sensorineural hearing loss, with an emphasis on noise. J Acoust Soc Am 2019; 146:3743. [PMID: 31795705 PMCID: PMC7195866 DOI: 10.1121/1.5132711] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/30/2019] [Accepted: 08/12/2019] [Indexed: 05/10/2023]
Abstract
Guinea pigs have been used in diverse studies to better understand acquired hearing loss induced by noise and ototoxic drugs. The guinea pig has its best hearing at slightly higher frequencies relative to humans, but its hearing is more similar to humans than the rat or mouse. Like other rodents, it is more vulnerable to noise injury than the human or nonhuman primate models. There is a wealth of information on auditory function and vulnerability of the inner ear to diverse insults in the guinea pig. With respect to the assessment of potential otoprotective agents, guinea pigs are also docile animals that are relatively easy to dose via systemic injections or gavage. Of interest, the cochlea and the round window are easily accessible, notably for direct cochlear therapy, as in the chinchilla, making the guinea pig a most relevant and suitable model for hearing. This article reviews the use of the guinea pig in basic auditory research, provides detailed discussion of its use in studies on noise injury and other injuries leading to acquired sensorineural hearing loss, and lists some therapeutics assessed in these laboratory animal models to prevent acquired sensorineural hearing loss.
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Affiliation(s)
| | | | - Colleen G Le Prell
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
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Affiliation(s)
- Lei Guo
- State Key Laboratory for Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, P.R. China
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, P.R. China
| | - Wei Zhang
- State Key Laboratory for Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, P.R. China
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, P.R. China
| | - Jialei Zhang
- State Key Laboratory for Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, P.R. China
- Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300130, P.R. China
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