The Cochlear Nucleus as a Generator of Tinnitus-Related Signals

Author(s):  
J.A. Kaltenbach ◽  
D.A. Godfrey

Tinnitus most commonly begins with alterations of input from the ear resulting from cochlear trauma or overstimulation of the ear. Because the cochlear nucleus is the first processing center in the brain receiving cochlear input, it is the first brainstem station to adjust to this modified input from the cochlea. Research published over the last 30 years demonstrates changes in neural circuitry and activity in the cochlear nucleus that are associated with and may be the origin of the signals that give rise to tinnitus percepts at the cortical level. This chapter summarizes what is known about these disturbances and their relationships to tinnitus. It also summarizes the mechanisms that trigger tinnitus-related disturbances and the anatomical, chemical, neurophysiological, and biophysical defects that underlie them. It concludes by highlighting some major controversies that research findings have generated and discussing the clinical implications the findings have for the future treatment of tinnitus.

2012 ◽  
Vol 13 (2) ◽  
pp. 32-42 ◽  
Author(s):  
Yvette D. Hyter

Abstract Complex trauma resulting from chronic maltreatment and prenatal alcohol exposure can significantly affect child development and academic outcomes. Children with histories of maltreatment and those with prenatal alcohol exposure exhibit remarkably similar central nervous system impairments. In this article, I will review the effects of each on the brain and discuss clinical implications for these populations of children.


1969 ◽  
Vol 21 (02) ◽  
pp. 294-303 ◽  
Author(s):  
H Mihara ◽  
T Fujii ◽  
S Okamoto

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.


We have new answers to how the brain works and tools which can now monitor and manipulate brain function. Rapid advances in neuroscience raise critical questions with which society must grapple. What new balances must be struck between diagnosis and prediction, and invasive and noninvasive interventions? Are new criteria needed for the clinical definition of death in cases where individuals are eligible for organ donation? How will new mobile and wearable technologies affect the future of growing children and aging adults? To what extent is society responsible for protecting populations at risk from environmental neurotoxins? As data from emerging technologies converge and are made available on public databases, what frameworks and policies will maximize benefits while ensuring privacy of health information? And how can people and communities with different values and perspectives be maximally engaged in these important questions? Neuroethics: Anticipating the Future is written by scholars from diverse disciplines—neurology and neuroscience, ethics and law, public health, sociology, and philosophy. With its forward-looking insights and considerations for the future, the book examines the most pressing current ethical issues.


Author(s):  
Robert V. Shannon

The auditory brainstem implant (ABI) is a surgically implanted device to electrically stimulate auditory neurons in the cochlear nucleus complex of the brainstem in humans to restore hearing sensations. The ABI is similar in function to a cochlear implant, but overall outcomes are poorer. However, recent applications of the ABI to new patient populations and improvements in surgical technique have led to significant improvements in outcomes. While the ABI provides hearing benefits to patients, the outcomes challenge our understanding of how the brain processes neural patterns of auditory information. The neural pattern of activation produced by an ABI is highly unnatural, yet some patients achieve high levels of speech understanding. Based on a meta-analysis of ABI surgeries and outcomes, a theory is proposed of a specialized sub-system of the cochlear nucleus that is critical for speech understanding.


1993 ◽  
Vol 5 (4) ◽  
pp. 71-75
Author(s):  
C. Aaldijk ◽  
W.W. Van Den Broek ◽  
R.C. Van Der Mast

SummaryIn this review the most important hypotheses for the occurrence of the clinical picture of hepatic encephalopathy are discussed. As possible pathogenetic mechanisms are raised: dysfunction of the serotonergic system due to an increased tryptophan uptake in the brain, an elevated intracerebral ammoniac concentration and glutamine synthesis, and a heightened intracerebral GABA-activity.The dysregulation of the serotonergic system as a consequence of the increased intracerebral tryptophan uptake is described as one of the most important pathogenetic mechanisms. The elevated intracerebral ammoniac concentration and the elevated intracerebral glutamine synthesis play in this a facilitating role. The similarity in symptomatology of the clinical picture of HE and the serotonergic syndrome support this hypothesis. Due to contradictory research findings the role of the GABA-ergic system and the occurrence of HE remains unclear.


2012 ◽  
Vol 17 (2) ◽  
pp. 184-186 ◽  
Author(s):  
Siobhan M. Schabrun ◽  
Lucinda S. Chipchase
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