Binaural interaction at the inferior colliculi.

1955 ◽  
Vol 48 (5) ◽  
pp. 426-431 ◽  
Author(s):  
Mark R. Rosenzweig ◽  
J. Wyers Everett
Keyword(s):  
Binaural Interaction ◽  
Inferior Colliculi

scholarly journals Speech Processing Disorder in Neural Hearing Loss

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Joseph P. Pillion
Keyword(s):  
Speech Processing ◽  
Auditory Processing ◽  
Neurological Disorders ◽  
Auditory Neuropathy ◽  
Central Auditory Processing ◽  
Temporal Lobes ◽  
Electrophysiological Tests ◽  
Bilateral Lesions ◽  
Clinical Conditions ◽  
Inferior Colliculi

Deficits in central auditory processing may occur in a variety of clinical conditions including traumatic brain injury, neurodegenerative disease, auditory neuropathy/dyssynchrony syndrome, neurological disorders associated with aging, and aphasia. Deficits in central auditory processing of a more subtle nature have also been studied extensively in neurodevelopmental disorders in children with learning disabilities, ADD, and developmental language disorders. Illustrative cases are reviewed demonstrating the use of an audiological test battery in patients with auditory neuropathy/dyssynchrony syndrome, bilateral lesions to the inferior colliculi, and bilateral lesions to the temporal lobes. Electrophysiological tests of auditory function were utilized to define the locus of dysfunction at neural levels ranging from the auditory nerve, midbrain, and cortical levels.

scholarly journals The Inferior Colliculus in Alcoholism and Beyond

2020 ◽  
Vol 14 ◽  
Author(s):  
Tanuja Bordia ◽  
Natalie M. Zahr
Keyword(s):  
Inferior Colliculus ◽  
Ethanol Exposure ◽  
Ethanol Withdrawal ◽  
Hypoxic Injury ◽  
Auditory Gating ◽  
Korsakoff Syndrome ◽  
Altered Metabolism ◽  
Magnetic Resonance Imaging Mri ◽  
Inferior Colliculi

Post-mortem neuropathological and in vivo neuroimaging methods have demonstrated the vulnerability of the inferior colliculus to the sequelae of thiamine deficiency as occurs in Wernicke-Korsakoff Syndrome (WKS). A rich literature in animal models ranging from mice to monkeys—including our neuroimaging studies in rats—has shown involvement of the inferior colliculi in the neural response to thiamine depletion, frequently accomplished with pyrithiamine, an inhibitor of thiamine metabolism. In uncomplicated alcoholism (i.e., absent diagnosable neurological concomitants), the literature citing involvement of the inferior colliculus is scarce, has nearly all been accomplished in preclinical models, and is predominately discussed in the context of ethanol withdrawal. Our recent work using novel, voxel-based analysis of structural Magnetic Resonance Imaging (MRI) has demonstrated significant, persistent shrinkage of the inferior colliculus using acute and chronic ethanol exposure paradigms in two strains of rats. We speculate that these consistent findings should be considered from the perspective of the inferior colliculi having a relatively high CNS metabolic rate. As such, they are especially vulnerable to hypoxic injury and may be provide a common anatomical link among a variety of disparate insults. An argument will be made that the inferior colliculi have functions, possibly related to auditory gating, necessary for awareness of the external environment. Multimodal imaging including diffusion methods to provide more accurate in vivo visualization and quantification of the inferior colliculi may clarify the roles of brain stem nuclei such as the inferior colliculi in alcoholism and other neuropathologies marked by altered metabolism.

Cochlear electrical stimulation: Influence of age of implantation on Fos immunocytochemical reactions in inferior colliculi and dorsal cochlear nuclei of the rat

2001 ◽  
Vol 438 (2) ◽  
pp. 226-238 ◽  
Author(s):  
Wei-Chung Hsu ◽  
Antonio Campos-Torres ◽  
Frederic Portier ◽  
Eric Lecain ◽  
Thierry Van Den Abbeele ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Nuclei ◽  
Inferior Colliculi

Sensitivity to interaural intensity differences of neurons in primary auditory cortex of the cat. I. types of sensitivity and effects of variations in sound pressure level

1996 ◽  
Vol 75 (1) ◽  
pp. 75-96 ◽  
Author(s):  
D. R. Irvine ◽  
R. Rajan ◽  
L. M. Aitkin
Keyword(s):  
Auditory Cortex ◽  
High Frequency ◽  
Primary Auditory Cortex ◽  
Mirror Image ◽  
Sensitivity Function ◽  
Maximum Response ◽  
Binaural Interaction ◽  
Sensitivity Functions ◽  
Monaural Stimulation ◽  
Stimulation Of

1. Interaural intensity differences (IIDs) provide the major cue to the azimuthal location of high-frequency narrowband sounds. In recent studies of the azimuthal sensitivity of high-frequency neurons in the primary auditory cortex (field AI) of the cat, a number of different types of azimuthal sensitivity have been described and the azimuthal sensitivity of many neurons was found to vary as a function of changes in stimulus intensity. The extent to which the shape and the intensity dependence of the azimuthal sensitivity of AI neurons reflects features of their IID sensitivity was investigated by obtaining data on IID sensitivity from a large sample of neurons with a characteristic frequency (CF) > 5.5 kHz in AI of anesthetized cats. IID sensitivity functions were classified in a manner that facilitated comparison with previously obtained data on azimuthal sensitivity, and the effects of changes in the base intensity at which IIDs were introduced were examined. 2. IID sensitivity functions for CF tonal stimuli were obtained at one or more intensities for a total of 294 neurons, in most cases by a method of generating IIDs that kept the average binaural intensity (ABI) of the stimuli at the two ears constant. In the standard ABI range at which a function was obtained for each unit, five types of IID sensitivity were distinguished. Contra-max neurons (50% of the sample) had maximum response (a peak or a plateau) at IIDs corresponding to contralateral azimuths, whereas ipsi-max neurons (17%) had the mirror-image form of sensitivity. Near-zero-max neurons (18%) had a clearly defined maximum response (peak) in the range of +/- 10 dB IID, whereas a small group of tough neurons (2%) had a restricted range of minimal responsiveness with near-maximal responses at IIDs on either side. A final 18% of AI neurons were classified as insensitive to IIDs. The proportions of neurons exhibiting the various types of sensitivity corresponded closely to the proportions found to exhibit corresponding types of azimuthal sensitivity in a previous study. 3. There was a strong correlation between a neuron's binaural interaction characteristics and the form of its IID sensitivity function. Thus, neurons excited by monaural stimulation of only one ear but with either inhibitory, facilitatory, or mixed facilitatory-inhibitory effects of stimulation of the other ear had predominantly contra-max IID sensitivity (if contralateral monaural stimulation was excitatory) or ipsi-max sensitivity (if ipsilateral monaural stimulation was excitatory). Neurons driven weakly or not at all by monaural stimulation but facilitated binaurally almost all exhibited near-zero-max IID sensitivity. The exception to this tight association between binaural input and IID sensitivity was provided by neurons excited by monaural stimulation of either ear (EE neurons). Although EE neurons have frequently been considered to be insensitive to IIDs, our data were in agreement with two recent reports indicating that they can exhibit various forms of IID sensitivity: only 23 of 75 EE neurons were classified as insensitive and the remainder exhibited diverse types of sensitivity. 4. IID sensitivity was examined at two or more intensities (3-5 in most cases) for 84 neurons. The form of the IID sensitivity function (defined in terms of both shape and position along the IID axis) was invariant with changes in ABI for only a small proportion of IID-sensitive neurons (approximately 15% if a strict criterion of invariance was employed), and for many of these neurons the spike counts associated with a given IID varied with ABI, particularly at near-threshold levels. When the patterns of variation in the form of IID sensitivity produced by changes in ABI were classified in a manner equivalent to that used previously to classify the effects of intensity on azimuthal sensitivity, there was a close correspondence between the effects of intensity on corresponding types of azimuthal and IID sensitivity

Inferior Colliculi

2013 ◽  
pp. 1606-1607
Author(s):  
Michael B. First ◽  
Elizabeth Spencer ◽  
Elizabeth Spencer ◽  
Sander Begeer ◽  
Brynn Thomas ◽  
...  
Keyword(s):  
Inferior Colliculi
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