Animal Models of Tinnitus: A Review.
Acoustic startle reflex; Animal models; Operant behavioral methods; Psychophysics; Tinnitus
Animal models have significantly contributed to understanding the pathophysiology of chronic subjective tinnitus. They are useful because they control etiology, which in humans is heterogeneous; employ random group assignment; and often use methods not permissible in human studies. Animal models can be broadly categorized as either operant or reflexive, based on methodology. Operant methods use variants of established psychophysical procedures to reveal what an animal hears. Reflexive methods do the same using elicited behavior, for example, the acoustic startle reflex. All methods contrast the absence of sound and presence of sound, because tinnitus cannot by definition be perceived as silence.
Galazyuk Alexander; Brozoski Thomas J
Otolaryngologic clinics of North America
2020
2020-04-20
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
journalArticle
<a href="http://doi.org/10.1016/j.otc.2020.03.001" target="_blank" rel="noreferrer noopener">10.1016/j.otc.2020.03.001</a>
Gap-Prepulse Inhibition of the Acoustic Startle Reflex (GPIAS) for Tinnitus Assessment: Current Status and Future Directions.
animal model of tinnitus; gap-prepulse inhibition of the startle reflex; human tinnitus; tinnitus assessment
The progress in the field of tinnitus largely depends on the development of a reliable tinnitus animal model. Recently, a new method based on the acoustic startle reflex modification was introduced for tinnitus screening in laboratory animals. This method was enthusiastically adopted and now widely used by many scientists in the field due to its seeming simplicity and a number of advantages over the other methods of tinnitus assessment. Furthermore, this method opened an opportunity for tinnitus assessment in humans as well. Unfortunately, multiple modifications of data collection and interpretation implemented in different labs make comparisons across studies very difficult. In addition, recent animal and human studies have challenged the original "filling-in" interpretation of the paradigm. Here, we review the current literature to emphasize on the commonalities and differences in data collection and interpretation across laboratories that are using this method for tinnitus assessment. We also propose future research directions that could be taken in order to establish whether or not this method is warranted as an indicator of the presence of tinnitus.
Galazyuk Alexander; Hebert Sylvie
Frontiers in neurology
2015
1905-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.3389/fneur.2015.00088" target="_blank" rel="noreferrer noopener">10.3389/fneur.2015.00088</a>
Intracellular recordings from combination-sensitive neurons in the inferior colliculus.
Acoustic Stimulation/methods; Afferent/classification/*physiology; Animals; Auditory/physiology; Biological; Chiroptera; Evoked Potentials; Inferior Colliculi/*cytology; Membrane Potentials/physiology/radiation effects; Models; Neural Inhibition/*physiology; Neural Pathways/physiology; Neurons; Psychophysics; Reaction Time; Wakefulness
In vertebrate auditory systems, specialized combination-sensitive neurons analyze complex vocal signals by integrating information across multiple frequency bands. We studied combination-sensitive interactions in neurons of the inferior colliculus (IC) of awake mustached bats, using intracellular somatic recording with sharp electrodes. Facilitated combinatorial neurons are coincidence detectors, showing maximum facilitation when excitation from low- and high-frequency stimuli coincide. Previous work showed that facilitatory interactions originate in the IC, require both low and high frequency-tuned glycinergic inputs, and are independent of glutamatergic inputs. These results suggest that glycinergic inputs evoke facilitation through either postinhibitory rebound or direct depolarizing mechanisms. However, in 35 of 36 facilitated neurons, we observed no evidence of low frequency-evoked transient hyperpolarization or depolarization that was closely related to response facilitation. Furthermore, we observed no evidence of shunting inhibition that might conceal inhibitory inputs. Since these facilitatory interactions originate in IC neurons, the results suggest that inputs underlying facilitation are electrically segregated from the soma. We also recorded inhibitory combinatorial interactions, in which low frequency sounds suppress responses to higher frequency signals. In 43% of 118 neurons, we observed low frequency-evoked hyperpolarizations associated with combinatorial inhibition. For these neurons, we conclude that low frequency-tuned inhibitory inputs terminate on neurons primarily excited by high-frequency signals; these inhibitory inputs may create or enhance inhibitory combinatorial interactions. In the remainder of inhibited combinatorial neurons (57%), we observed no evidence of low frequency-evoked hyperpolarizations, consistent with observations that inhibitory combinatorial responses may originate in lateral lemniscal nuclei.
Peterson Diana Coomes; Voytenko Sergiy; Gans Donald; Galazyuk Alexander; Wenstrup Jeffrey
Journal of neurophysiology
2008
2008-08
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1152/jn.90390.2008" target="_blank" rel="noreferrer noopener">10.1152/jn.90390.2008</a>