A5067404796- Hearing, Cochlea, Tinnitus, Genetics
- Hearing Loss and Rehabilitation
- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Vestibular and auditory disorders
- Biochemical Analysis and Sensing Techniques
- Genetic Neurodegenerative Diseases
- Neuroscience and Neural Engineering
- Photoreceptor and optogenetics research
- Ion Channels and Receptors
- Ion channel regulation and function
- Acute Ischemic Stroke Management
- Botulinum Toxin and Related Neurological Disorders
- Neuroscience of respiration and sleep
- Tumors and Oncological Cases
- Genetic and rare skin diseases.
- Neonatal and fetal brain pathology
- Retinal Development and Disorders
- Vascular Malformations and Hemangiomas
- Acoustic Wave Phenomena Research
- CCD and CMOS Imaging Sensors
- Neurological disorders and treatments
- Neuroscience and Music Perception
- Traumatic Brain Injury and Neurovascular Disturbances
National Institute on Deafness and Other Communication Disorders
2010-2025
National Institutes of Health
2021-2024
University of Pittsburgh
2014-2021
Johns Hopkins University
2004-2014
Johns Hopkins Medicine
2004-2014
Society for Neuroscience
2009
Brainstem olivocochlear neurons (OCNs) modulate the earliest stages of auditory processing through feedback projections to cochlea and have been shown influence hearing protect ear from sound-induced damage. Here, we used single-nucleus sequencing, anatomical reconstructions, electrophysiology characterize murine OCNs during postnatal development, in mature animals, after sound exposure. We identified markers for known medial (MOC) lateral (LOC) OCN subtypes, show that they express distinct...
Type II cochlear afferents receive glutamatergic synaptic excitation from outer hair cells (OHCs) in the rat cochlea. However, it remains uncertain whether this connection is capable of providing auditory information to brain. The functional efficacy depends part on number presynaptic OHCs, their probability transmitter release, and effective electrical distance for spatial summation type fiber. present work addresses these questions using whole-cell recordings spiral process that run below...
Cochlear outer hair cells (OHCs) are known to uniquely participate in auditory processing through their electromotility, and like inner cells, also capable of releasing vesicular glutamate onto spiral ganglion (SG) neurons: this case, the sparse Type II SG neurons. However, unlike signaling at cell-Type I neuron synapse, which is robust across a wide spectrum sound intensities, OHC-Type synapse weaker has been hypothesized occur only intense, possibly damaging levels. Here, we tested ability...
Cochlear outer hair cells (OHCs) are electromotile and implicated in amplification of responses to sound that enhance sensitivity frequency tuning. They send afferent information through glutamatergic synapses onto type II spiral ganglion neurons (SGNs). These weaker than those from cochlear inner I SGN, suggesting SGNs respond only intense levels. OHCs also receive efferent innervation medial olivocochlear (MOC) neurons. MOC cholinergic yet inhibit due the functional coupling alpha9/alpha10...
Two types of sensory hair cells in the mammalian cochlea signal through anatomically distinct populations spiral ganglion afferent neurons. The solitary inner cell ribbon synapse uses multivesicular release to trigger action potentials that encode acoustic timing, intensity, and frequency each type I afferent. In contrast, cochlear outer (OHCs) have a far weaker effect on their postsynaptic targets, II afferents. OHCs typically single vesicles with low probability so extensive summation is...
Abstract Mechanosensory hair cells release glutamate at ribbon synapses to excite postsynaptic afferent neurons, via AMPA-type ionotropic receptors (AMPARs). However, type II neurons contacting outer in the mammalian cochlea were thought differ this respect, failing show GluA immunolabeling and with many “ribbonless” contacts. Here it is shown that antibodies AMPAR subunit GluA2 labeled contacts below inner rat cochlea, synaptic currents afferents had AMPAR-specific pharmacology. Only half...
Humans with the disorder episodic ataxia type 2 (EA2) and tottering mouse mutant exhibit attacks induced by emotional chemical stress. Both human disorders result from mutations in CACNA1A , gene encoding α 1 2.1 subunit of Ca v voltage-gated calcium channels. These predict reduced currents, particularly cerebellar Purkinje cells, where these channels are most abundant. 4-Aminopyridine (4-AP), a nonselective blocker K potassium channels, alleviates EA2 patients. To test specificity effect...
Medial olivocochlear (MOC) efferent neurons in the brainstem comprise final stage of descending control mammalian peripheral auditory system through axon projections to cochlea. MOC activity adjusts cochlear gain and frequency tuning, protects ear from acoustic trauma. The neuronal pathways that activate modulate somata drive these effects are poorly understood. Evidence suggests primarily excited by sound stimuli a three-neuron activation loop nerve via an intermediate neuron nucleus....
Synapses from neurons of the medial nucleus trapezoid body (MNTB) onto lateral superior olive (LSO) in auditory brainstem are glycinergic maturity, but also GABAergic and glutamatergic development. The role for this neurotransmitter cotransmission is poorly understood. Here we use electrophysiological recordings slices P3-P21 mice to demonstrate that GABA release evoked MNTB axons can spill over neighboring cause excitation by activating A R. This spillover generates patterns staggered...
Abstract Cochlear outer hair cells (OHCs) are electromotile and implicated in mechanisms of amplification responses to sound that enhance sensitivity frequency tuning. They send information the brain through glutamatergic synapses onto a small subpopulation neurons ascending auditory nerve, type II spiral ganglion (SGNs). The OHC SGNs sparse weak, suggesting respond primarily loud possibly damaging levels sound. OHCs also receive innervation from medial olivocochlear (MOC) efferent neurons....
Sturge-Weber syndrome presents with vascular malformations of the brain, skin, and eye. Fibronectin has potent effects on angiogenesis, vessel remodeling, innervation density. To determine fibronectin expression in blood vessels brain skin tissue to quantify density circumference by type compared controls, we performed situ hybridization for messenger ribonucleic acid (RNA) six cortical samples, epilepsy from two port-wine stain lesions, normal samples subjects syndrome. RNA was expressed...
The descending auditory system modulates the ascending at every level. final descending, or efferent, stage comprises lateral olivocochlear and medial (MOC) neurons. MOC somata in ventral brainstem project axons to cochlea synapse onto outer hair cells (OHC), inhibiting OHC-mediated cochlear amplification. suppression of OHC function is implicated gain control with changing sound intensity, detection salient stimuli, attention protection against acoustic trauma. Thus, excites neurons provide...
During development, inner hair cells (IHCs) in the mammalian cochlea are unresponsive to acoustic stimuli but instead exhibit spontaneous activity. this same period, neurons originating from medial olivocochlear complex (MOC) transiently innervate IHCs, regulating their firing pattern which is crucial for correct development of auditory pathway. Although MOC-IHC a cholinergic synapse, previous evidence indicates widespread presence gamma-aminobutyric acid (GABA) signaling markers, including...
News & Views26 July 2020Open Access Shedding light on optical cochlear implant progress Siân R Kitcher Section Neuronal Circuitry, National Institute Deafness and Other Communication Disorders, NIH, Bethesda, MD, USA Search for more papers by this author Catherine JC Weisz Corresponding Author [email protected] orcid.org/0000-0002-2595-835X Information Kitcher1 *,1 1Section *Corresponding author. E-mail: EMBO Mol Med (2020)12:e12620https://doi.org/10.15252/emmm.202012620 See also: A Dieter...
The encoding of acoustic stimuli requires precise neuron timing. Auditory neurons in the cochlear nucleus (CN) and brainstem are well suited for accurate analysis fast signals, given their physiological specializations membrane time constants, axonal conduction, reliable synaptic transmission. medial olivocochlear (MOC) that provide efferent inhibition cochlea reside ventral participate these neural circuits. However, modulation function occurs over scales a slower nature. This suggests...
In vitro slice electrophysiology techniques measure single-cell activity with precise electrical and temporal resolution. Brain slices must be relatively thin to properly visualize access neurons for patch-clamping or imaging, in examination of brain circuitry is limited only what physically present the acute slice. To maintain benefits experimentation while preserving a larger portion presynaptic nuclei, we developed novel preparation. This "wedge slice" was designed patch-clamp recordings...
SUMMARY Brainstem olivocochlear neurons (OCNs) modulate the earliest stages of auditory processing through feedback projections to cochlea and have been shown influence hearing protect ear from sound-induced damage unclear mechanisms. Here, we used single-nucleus sequencing, anatomical reconstructions, electrophysiology characterize OCNs during postnatal development after sound exposure. We identified markers for known OCN subtypes, medial (MOC) lateral (LOC) OCNs, show that they express...