Circuitry underlying spectrotemporal integration in the auditory midbrain.
Female; Male; Time Factors; Animals; Acoustic Stimulation/*methods; Chiroptera; Auditory Pathways/*physiology; Mesencephalon/*physiology; Nerve Net/*physiology
Combination sensitivity in central auditory neurons is a form of spectrotemporal integration in which excitatory responses to sounds at one frequency are facilitated by sounds within a distinctly different frequency band. Combination-sensitive neurons respond selectively to acoustic elements of sonar echoes or social vocalizations. In mustached bats, this response property originates in high-frequency representations of the inferior colliculus (IC) and depends on low and high frequency-tuned glycinergic inputs. To identify the source of these inputs, we combined glycine immunohistochemistry with retrograde tract tracing. Tracers were deposited at high-frequency (\textgreater56 kHz), combination-sensitive recording sites in IC. Most glycine-immunopositive, retrogradely labeled cells were in ipsilateral ventral and intermediate nuclei of the lateral lemniscus (VNLL and INLL), with some double labeling in ipsilateral lateral and medial superior olivary nuclei (LSO and MSO). Generally, double-labeled cells were in expected high-frequency tonotopic areas, but some VNLL and INLL labeling appeared to be in low-frequency representations. To test whether these nuclei provide low frequency-tuned input to the high-frequency IC, we combined retrograde tracing from IC combination-sensitive sites with anterograde tracing from low frequency-tuned sites in the anteroventral cochlear nucleus (AVCN). Only VNLL and INLL contained retrogradely labeled cells near (
Yavuzoglu Asuman; Schofield Brett R; Wenstrup Jeffrey J
The Journal of neuroscience : the official journal of the Society for Neuroscience
2011
2011-10
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/10.1523/JNEUROSCI.3529-11.2011" target="_blank" rel="noreferrer noopener">10.1523/JNEUROSCI.3529-11.2011</a>
Coding the meaning of sounds: contextual modulation of auditory responses in the basolateral amygdala.
Female; Male; Animals; Mice; Acoustic Stimulation/*methods; Auditory Perception/*physiology; Action Potentials/*physiology; Amygdala/*physiology; Cats; Animal/*physiology; Inbred CBA; Vocalization
Female mice emit a low-frequency harmonic (LFH) call in association with distinct behavioral contexts: mating and physical threat or pain. Here we report the results of acoustic, behavioral, and neurophysiological studies of the contextual analysis of these calls in CBA/CaJ mice. We first show that the acoustical features of the LFH call do not differ between contexts. We then show that male mice avoid the LFH call in the presence of a predator cue (cat fur) but are more attracted to the same exemplar of the call in the presence of a mating cue (female urine). The males thus use nonauditory cues to determine the meaning of the LFH call, but these cues do not generalize to noncommunication sounds, such as noise bursts. We then characterized neural correlates of contextual meaning of the LFH call in responses of basolateral amygdala (BLA) neurons from awake, freely moving mice. There were two major findings. First, BLA neurons typically displayed early excitation to all tested behaviorally aversive stimuli. Second, the nonauditory context modulates the BLA population response to the LFH call but not to the noncommunication sound. These results suggest that the meaning of communication calls is reflected in the spike discharge patterns of BLA neurons.
Grimsley Jasmine M S; Hazlett Emily G; Wenstrup Jeffrey J
The Journal of neuroscience : the official journal of the Society for Neuroscience
2013
2013-10
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/10.1523/JNEUROSCI.2205-13.2013" target="_blank" rel="noreferrer noopener">10.1523/JNEUROSCI.2205-13.2013</a>
Brief Stimulus Exposure Fully Remediates Temporal Processing Deficits Induced by Early Hearing Loss.
Female; Male; Animals; Age Factors; *auditory cortex; *development; *gap detection; *hearing loss; *remediation; *temporal coding; Acoustic Stimulation/*methods; Auditory Cortex/*physiology/*physiopathology; Auditory Perception/*physiology; Gerbillinae; Hearing Loss/*physiopathology; Brain Stem/*physiology; Evoked Potentials; Auditory
In childhood, partial hearing loss can produce prolonged deficits in speech perception and temporal processing. However, early therapeutic interventions targeting temporal processing may improve later speech-related outcomes. Gap detection is a measure of auditory temporal resolution that relies on the auditory cortex (ACx), and early auditory deprivation alters intrinsic and synaptic properties in the ACx. Thus, early deprivation should induce deficits in gap detection, which should be reflected in ACx gap sensitivity. We tested whether earplugging-induced, early transient auditory deprivation in male and female Mongolian gerbils caused correlated deficits in behavioral and cortical gap detection, and whether these could be rescued by a novel therapeutic approach: brief exposure to gaps in background noise. Two weeks after earplug removal, animals that had been earplugged from hearing onset throughout auditory critical periods displayed impaired behavioral gap detection thresholds (GDTs), but this deficit was fully reversed by three 1 h sessions of exposure to gaps in noise. In parallel, after earplugging, cortical GDTs increased because fewer cells were sensitive to short gaps, and gap exposure normalized this pattern. Furthermore, in deprived animals, both first-spike latency and first-spike latency jitter increased, while spontaneous and evoked firing rates decreased, suggesting that deprivation causes a wider range of perceptual problems than measured here. These cortical changes all returned to control levels after gap exposure. Thus, brief stimulus exposure, perhaps in a salient context such as the unfamiliar placement into a testing apparatus, rescued impaired gap detection and may have potential as a remediation tool for general auditory processing deficits.SIGNIFICANCE STATEMENT Hearing loss in early childhood leads to impairments in auditory perception and language processing that can last well beyond the restoration of hearing sensitivity. Perceptual deficits can be improved by training, or by acoustic enrichment in animal models, but both approaches involve extended time and effort. Here, we used a novel remediation technique, brief periods of auditory stimulus exposure, to fully remediate cortical and perceptual deficits in gap detection induced by early transient hearing loss. This technique also improved multiple cortical response properties. Rescue by this efficient exposure regime may have potential as a therapeutic tool to remediate general auditory processing deficits in children with perceptual challenges arising from early hearing loss.
Green David B; Mattingly Michelle M; Ye Yi; Gay Jennifer D; Rosen Merri J
The Journal of neuroscience : the official journal of the Society for Neuroscience
2017
2017-08
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/10.1523/JNEUROSCI.0916-17.2017" target="_blank" rel="noreferrer noopener">10.1523/JNEUROSCI.0916-17.2017</a>
Prepulse inhibition of the acoustic startle reflex vs. auditory brainstem response for hearing assessment.
*Audiometric functions; *Hearing loss; *Mouse; *Permanent threshold shift; *Sound exposure; *Temporary threshold shift; Acoustic Stimulation/*methods; Animal; Animals; Audiometry; Auditory; Auditory Threshold/*physiology; Brain Stem/*physiology; Evoked Potentials; Hearing; Inbred CBA; Male; Mice; Models; Noise; Prepulse Inhibition/*physiology; Pure-Tone/*methods; Reflex; Startle/*physiology
The high prevalence of noise-induced and age-related hearing loss in the general population has warranted the use of animal models to study the etiology of these pathologies. Quick and accurate auditory threshold determination is a prerequisite for experimental manipulations targeting hearing loss in animal models. The standard auditory brainstem response (ABR) measurement is fairly quick and translational across species, but is limited by the need for anesthesia and a lack of perceptual assessment. The goal of this study was to develop a new method of hearing assessment utilizing prepulse inhibition (PPI) of the acoustic startle reflex, a commonly used tool that measures detection thresholds in awake animals, and can be performed on multiple animals simultaneously. We found that in control mice PPI audiometric functions are similar to both ABR and traditional operant conditioning audiograms. The hearing thresholds assessed with PPI audiometry in sound exposed mice were also similar to those detected by ABR thresholds one day after exposure. However, three months after exposure PPI threshold shifts were still evident at and near the frequency of exposure whereas ABR thresholds recovered to the pre-exposed level. In contrast, PPI audiometry and ABR wave one amplitudes detected similar losses. PPI audiometry provides a high throughput automated behavioral screening tool of hearing in awake animals. Overall, PPI audiometry and ABR assessments of the auditory system are robust techniques with distinct advantages and limitations, which when combined, can provide ample information about the functionality of the auditory system.
Longenecker R J; Alghamdi F; Rosen M J; Galazyuk A V
Hearing research
2016
2016-09
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/10.1016/j.heares.2016.06.006" target="_blank" rel="noreferrer noopener">10.1016/j.heares.2016.06.006</a>