scholarly journals The multiple-channel cochlear implant: the interface between sound and the central nervous system for hearing, speech, and language in deaf people—a personal perspective

2006 ◽  
Vol 361 (1469) ◽  
pp. 791-810 ◽  
Author(s):  
Graeme M Clark

The multiple-channel cochlear implant is the first sensori-neural prosthesis to effectively and safely bring electronic technology into a direct physiological relation with the central nervous system and human consciousness, and to give speech perception to severely-profoundly deaf people and spoken language to children. Research showed that the place and temporal coding of sound frequencies could be partly replicated by multiple-channel stimulation of the auditory nerve. This required safety studies on how to prevent the effects to the cochlea of trauma, electrical stimuli, biomaterials and middle ear infection. The mechanical properties of an array and mode of stimulation for the place coding of speech frequencies were determined. A fully implantable receiver–stimulator was developed, as well as the procedures for the clinical assessment of deaf people, and the surgical placement of the device. The perception of electrically coded sounds was determined, and a speech processing strategy discovered that enabled late-deafened adults to comprehend running speech. The brain processing systems for patterns of electrical stimuli reproducing speech were elucidated. The research was developed industrially, and improvements in speech processing made through presenting additional speech frequencies by place coding. Finally, the importance of the multiple-channel cochlear implant for early deafened children was established.

2014 ◽  
Vol 16 (1) ◽  
pp. 397-430 ◽  
Author(s):  
Deanna M. Thompson ◽  
Abigail N. Koppes ◽  
John G. Hardy ◽  
Christine E. Schmidt

Loquens ◽  
2017 ◽  
Vol 4 (1) ◽  
pp. 035
Author(s):  
Pedro Gómez Vilda

Neurological deterioration presents different variants depending on their classification criterion, which may be their anatomic localization or their disease clinical features, although there is not a clear cut between both. Anatomically this ample group of disorders may affect the central nervous system (brain and spinal cord), or the peripheral nervous system. Clinically, the neurodegenerative disorders are classified as affecting cognitive functions or neuromotor capabilities. In the group of neurodegenerative diseases of the central nervous system, Alzheimer’s disease (AD) or Fronto-Temporal Dementia (FTD) are to be found, whereas in the second group certain pathologies as Parkinson’s Disease (PD), Amyotrophic Lateral Sclerosis (ALS), Huntington’s Disease (HD) or myasthenia gravis (MG) are among the most frequent ones, although “the number of neurodegenerative diseases is currently estimated to be a few hundred” (Przedborski et al., 2003). All these pathologies produce correlates in speech at different levels: in fluency, in prosody, in articulation or in phonation. Speech technologies offer computer solutions to evaluate objectively detected anomalies in each level, adding statistical robustness, which makes them suitable for their clinical and rehabilitative application. The present issue is devoted to briefly review the characteristics of the diseases mentioned before, defining the foundations of the correlate features present in each one. Some computer solutions available in detecting and monitoring illness progress are reviewed in the contributions of different research groups working in this field.


2012 ◽  
Vol 269 (5) ◽  
pp. 1555-1563 ◽  
Author(s):  
Aline Gomes Bittencourt ◽  
Maria Valéria Schmidt Goffi-Gomez ◽  
Mariana Hausen Pinna ◽  
Ricardo Ferreira Bento ◽  
Rubens de Brito ◽  
...  

Author(s):  
Gladys Harrison

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.


Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.


Author(s):  
Ezzatollah Keyhani

Acetylcholinesterase (EC 3.1.1.7) (ACHE) has been localized at cholinergic junctions both in the central nervous system and at the periphery and it functions in neurotransmission. ACHE was also found in other tissues without involvement in neurotransmission, but exhibiting the common property of transporting water and ions. This communication describes intracellular ACHE in mammalian bone marrow and its secretion into the extracellular medium.


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