Cochlear Nucleus: The brain stem nucleus that receives the central input from the cochlear nerve. The cochlear nucleus is located lateral and dorsolateral to the inferior cerebellar peduncles and is functionally divided into dorsal and ventral parts. It is tonotopically organized, performs the first stage of central auditory processing, and projects (directly or indirectly) to higher auditory areas including the superior olivary nuclei, the medial geniculi, the inferior colliculi, and the auditory cortex.Cochlear Nerve: The cochlear part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The cochlear nerve fibers originate from neurons of the SPIRAL GANGLION and project peripherally to cochlear hair cells and centrally to the cochlear nuclei (COCHLEAR NUCLEUS) of the BRAIN STEM. They mediate the sense of hearing.Auditory Pathways: NEURAL PATHWAYS and connections within the CENTRAL NERVOUS SYSTEM, beginning at the hair cells of the ORGAN OF CORTI, continuing along the eighth cranial nerve, and terminating at the AUDITORY CORTEX.Vestibulocochlear Nerve: The 8th cranial nerve. The vestibulocochlear nerve has a cochlear part (COCHLEAR NERVE) which is concerned with hearing and a vestibular part (VESTIBULAR NERVE) which mediates the sense of balance and head position. The fibers of the cochlear nerve originate from neurons of the SPIRAL GANGLION and project to the cochlear nuclei (COCHLEAR NUCLEUS). The fibers of the vestibular nerve arise from neurons of Scarpa's ganglion and project to the VESTIBULAR NUCLEI.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Acoustic Stimulation: Use of sound to elicit a response in the nervous system.Evoked Potentials, Auditory, Brain Stem: Electrical waves in the CEREBRAL CORTEX generated by BRAIN STEM structures in response to auditory click stimuli. These are found to be abnormal in many patients with CEREBELLOPONTINE ANGLE lesions, MULTIPLE SCLEROSIS, or other DEMYELINATING DISEASES.Olivary Nucleus: A part of the MEDULLA OBLONGATA situated in the olivary body. It is involved with motor control and is a major source of sensory input to the CEREBELLUM.Tinnitus: A nonspecific symptom of hearing disorder characterized by the sensation of buzzing, ringing, clicking, pulsations, and other noises in the ear. Objective tinnitus refers to noises generated from within the ear or adjacent structures that can be heard by other individuals. The term subjective tinnitus is used when the sound is audible only to the affected individual. Tinnitus may occur as a manifestation of COCHLEAR DISEASES; VESTIBULOCOCHLEAR NERVE DISEASES; INTRACRANIAL HYPERTENSION; CRANIOCEREBRAL TRAUMA; and other conditions.Brain Stem: The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.Inferior Colliculi: The posterior pair of the quadrigeminal bodies which contain centers for auditory function.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Gerbillinae: A subfamily of the Muridae consisting of several genera including Gerbillus, Rhombomys, Tatera, Meriones, and Psammomys.Noise: Any sound which is unwanted or interferes with HEARING other sounds.Cochlea: The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.Auditory Brain Stem Implants: Multi-channel hearing devices typically used for patients who have tumors on the COCHLEAR NERVE and are unable to benefit from COCHLEAR IMPLANTS after tumor surgery that severs the cochlear nerve. The device electrically stimulates the nerves of cochlea nucleus in the BRAIN STEM rather than the inner ear as in cochlear implants.Auditory Threshold: The audibility limit of discriminating sound intensity and pitch.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Pitch Perception: A dimension of auditory sensation varying with cycles per second of the sound stimulus.Auditory Perception: The process whereby auditory stimuli are selected, organized, and interpreted by the organism.Trigeminal Nucleus, Spinal: Nucleus of the spinal tract of the trigeminal nerve. It is divided cytoarchitectonically into three parts: oralis, caudalis (TRIGEMINAL CAUDAL NUCLEUS), and interpolaris.Neural Inhibition: The function of opposing or restraining the excitation of neurons or their target excitable cells.Sound Localization: Ability to determine the specific location of a sound source.Evoked Potentials, Auditory: The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.Chinchilla: A genus of the family Chinchillidae which consists of three species: C. brevicaudata, C. lanigera, and C. villidera. They are used extensively in biomedical research.Nerve Fibers: Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.Synapses: Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.Sound: A type of non-ionizing radiation in which energy is transmitted through solid, liquid, or gas as compression waves. Sound (acoustic or sonic) radiation with frequencies above the audible range is classified as ultrasonic. Sound radiation below the audible range is classified as infrasonic.Synaptic Transmission: The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.Spiral Ganglion: The sensory ganglion of the COCHLEAR NERVE. The cells of the spiral ganglion send fibers peripherally to the cochlear hair cells and centrally to the COCHLEAR NUCLEI of the BRAIN STEM.Vesicular Glutamate Transport Protein 2: A vesicular glutamate transporter protein that is predominately expressed in the DIENCEPHALON and lower brainstem regions of the CENTRAL NERVOUS SYSTEM.Strychnine: An alkaloid found in the seeds of STRYCHNOS NUX-VOMICA. It is a competitive antagonist at glycine receptors and thus a convulsant. It has been used as an analeptic, in the treatment of nonketotic hyperglycinemia and sleep apnea, and as a rat poison.Nucleus Accumbens: Collection of pleomorphic cells in the caudal part of the anterior horn of the LATERAL VENTRICLE, in the region of the OLFACTORY TUBERCLE, lying between the head of the CAUDATE NUCLEUS and the ANTERIOR PERFORATED SUBSTANCE. It is part of the so-called VENTRAL STRIATUM, a composite structure considered part of the BASAL GANGLIA.Hearing Loss, Noise-Induced: Hearing loss due to exposure to explosive loud noise or chronic exposure to sound level greater than 85 dB. The hearing loss is often in the frequency range 4000-6000 hertz.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Hearing Loss, Central: Hearing loss due to disease of the AUDITORY PATHWAYS (in the CENTRAL NERVOUS SYSTEM) which originate in the COCHLEAR NUCLEI of the PONS and then ascend bilaterally to the MIDBRAIN, the THALAMUS, and then the AUDITORY CORTEX in the TEMPORAL LOBE. Bilateral lesions of the auditory pathways are usually required to cause central hearing loss. Cortical deafness refers to loss of hearing due to bilateral auditory cortex lesions. Unilateral BRAIN STEM lesions involving the cochlear nuclei may result in unilateral hearing loss.Anterior Thalamic Nuclei: Three nuclei located beneath the dorsal surface of the most rostral part of the thalamus. The group includes the anterodorsal nucleus, anteromedial nucleus, and anteroventral nucleus. All receive connections from the MAMILLARY BODY and BRAIN FORNIX, and project fibers to the CINGULATE BODY.Vesicle-Associated Membrane Protein 1: A member of the vesicle-associated membrane protein family involved in the MEMBRANE FUSION of TRANSPORT VESICLES to their target membrane.Mice, Inbred CBAExcitatory Postsynaptic Potentials: Depolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during neurotransmission. Excitatory postsynaptic potentials can singly or in summation reach the trigger threshold for ACTION POTENTIALS.Afferent Pathways: Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Vesicular Glutamate Transport Protein 1: A vesicular glutamate transporter protein that is predominately expressed in TELENCEPHALON of the BRAIN.Strigiformes: An order of BIRDS with the common name owls characterized by strongly hooked beaks, sharp talons, large heads, forward facing eyes, and facial disks. While considered nocturnal RAPTORS, some owls do hunt by day.Tensor Tympani: A short muscle that arises from the pharyngotympanic tube (EUSTACHIAN TUBE) and inserts into the handle of the MALLEUS. This muscle pulls the handle medially thus controlling the tension and movement of TYMPANIC MEMBRANE.Decerebrate State: A condition characterized by abnormal posturing of the limbs that is associated with injury to the brainstem. This may occur as a clinical manifestation or induced experimentally in animals. The extensor reflexes are exaggerated leading to rigid extension of the limbs accompanied by hyperreflexia and opisthotonus. This condition is usually caused by lesions which occur in the region of the brainstem that lies between the red nuclei and the vestibular nuclei. In contrast, decorticate rigidity is characterized by flexion of the elbows and wrists with extension of the legs and feet. The causative lesion for this condition is located above the red nuclei and usually consists of diffuse cerebral damage. (From Adams et al., Principles of Neurology, 6th ed, p358)Hearing Loss, Conductive: Hearing loss due to interference with the mechanical reception or amplification of sound to the COCHLEA. The interference is in the outer or middle ear involving the EAR CANAL; TYMPANIC MEMBRANE; or EAR OSSICLES.Thalamic Nuclei: Several groups of nuclei in the thalamus that serve as the major relay centers for sensory impulses in the brain.Reaction Time: The time from the onset of a stimulus until a response is observed.Solitary Nucleus: GRAY MATTER located in the dorsomedial part of the MEDULLA OBLONGATA associated with the solitary tract. The solitary nucleus receives inputs from most organ systems including the terminations of the facial, glossopharyngeal, and vagus nerves. It is a major coordinator of AUTONOMIC NERVOUS SYSTEM regulation of cardiovascular, respiratory, gustatory, gastrointestinal, and chemoreceptive aspects of HOMEOSTASIS. The solitary nucleus is also notable for the large number of NEUROTRANSMITTERS which are found therein.Glycine Agents: Substances used for their pharmacological actions on glycinergic systems. Glycinergic agents include agonists, antagonists, degradation or uptake inhibitors, depleters, precursors, and modulators of receptor function.Pons: The front part of the hindbrain (RHOMBENCEPHALON) that lies between the MEDULLA and the midbrain (MESENCEPHALON) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the CEREBELLUM to the CEREBRUM.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Glycine: A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.Deafness: A general term for the complete loss of the ability to hear from both ears.Patch-Clamp Techniques: An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.Mice, Inbred ICRGAP-43 Protein: A nervous tissue specific protein which is highly expressed in NEURONS during development and NERVE REGENERATION. It has been implicated in neurite outgrowth, long-term potentiation, SIGNAL TRANSDUCTION, and NEUROTRANSMITTER release. (From Neurotoxicology 1994;15(1):41-7) It is also a substrate of PROTEIN KINASE C.Dendrites: Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.Vestibular Nucleus, Lateral: Vestibular nucleus lying immediately superior to the inferior vestibular nucleus and composed of large multipolar nerve cells. Its upper end becomes continuous with the superior vestibular nucleus.Hearing: The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.Animals, Newborn: Refers to animals in the period of time just after birth.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Raphe Nuclei: Collections of small neurons centrally scattered among many fibers from the level of the TROCHLEAR NUCLEUS in the midbrain to the hypoglossal area in the MEDULLA OBLONGATA.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Differential Threshold: The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold.Inhibitory Postsynaptic Potentials: Hyperpolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during NEUROTRANSMISSION. They are local changes which diminish responsiveness to excitatory signals.Neuronal Plasticity: The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.Cerebellar Nuclei: Four clusters of neurons located deep within the WHITE MATTER of the CEREBELLUM, which are the nucleus dentatus, nucleus emboliformis, nucleus globosus, and nucleus fastigii.Septal Nuclei: Neural nuclei situated in the septal region. They have afferent and cholinergic efferent connections with a variety of FOREBRAIN and BRAIN STEM areas including the HIPPOCAMPAL FORMATION, the LATERAL HYPOTHALAMUS, the tegmentum, and the AMYGDALA. Included are the dorsal, lateral, medial, and triangular septal nuclei, septofimbrial nucleus, nucleus of diagonal band, nucleus of anterior commissure, and the nucleus of stria terminalis.Active Transport, Cell Nucleus: Gated transport mechanisms by which proteins or RNA are moved across the NUCLEAR MEMBRANE.Elapid Venoms: Venoms from snakes of the family Elapidae, including cobras, kraits, mambas, coral, tiger, and Australian snakes. The venoms contain polypeptide toxins of various kinds, cytolytic, hemolytic, and neurotoxic factors, but fewer enzymes than viper or crotalid venoms. Many of the toxins have been characterized.Arcuate Nucleus: A nucleus located in the middle hypothalamus in the most ventral part of the third ventricle near the entrance of the infundibular recess. Its small cells are in close contact with the ependyma.Caudate Nucleus: Elongated gray mass of the neostriatum located adjacent to the lateral ventricle of the brain.GABA Antagonists: Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.Receptors, Glycine: Cell surface receptors that bind GLYCINE with high affinity and trigger intracellular changes which influence the behavior of cells. Glycine receptors in the CENTRAL NERVOUS SYSTEM have an intrinsic chloride channel and are usually inhibitory.Horseradish Peroxidase: An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.Paraventricular Hypothalamic Nucleus: Nucleus in the anterior part of the HYPOTHALAMUS.Axons: Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.Hearing Loss, High-Frequency: Hearing loss in frequencies above 1000 hertz.Psychoacoustics: The science pertaining to the interrelationship of psychologic phenomena and the individual's response to the physical properties of sound.Interneurons: Most generally any NEURONS which are not motor or sensory. Interneurons may also refer to neurons whose AXONS remain within a particular brain region in contrast to projection neurons, which have axons projecting to other brain regions.Receptors, AMPA: A class of ionotropic glutamate receptors characterized by their affinity for the agonist AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid).Time Perception: The ability to estimate periods of time lapsed or duration of time.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.