Electrohcemical Involvement in the Senses
Peter Kovacic1*, Ratnasamy Somanathan2
1Department
of Chemistry and Biochemistry, San Diego State University, San Diego, USA
2Centro de Graduados e Investigación del Instituto Tecnológico de Tijuana, Tijuana, B.C, Mexico
*Corresponding author: Peter Kovacic, Department of Chemistry and Biochemistry, San Diego State University, San Diego CA 92182, USA. Email: pkovacic@sundown.sdsu.edu
Received Date: 07 October, 2017; Accepted Date: 06 November, 2017; Published Date: 13 November, 2017
Citation: Kovacic P, Somanathan R (2017) Electrochemical Involvement in the Senses. Adv Biochem Biotehcnol 2: 144. DOI: 10.29011/2574-7258.000044
1. Abstract
There has been recent application of electrochemistry to unifying mode of action by odor and taste. This review extends the mechanistic approach to the other senses, namely touch, vision and hearing. A major difference among the senses is that molecules are initially involved in the case of odor and taste. The theory is based on a four-step process for odor and taste. The literature contains numerous reports dealing with electrochemistry in all cases, including electrical stimulation. The various factors involved are dipoles, electron transfer, receptor binding, radical species, neurochemistry and cell signaling. Other modes may be operative.
2. Keywords: Electrochemical; Five Senses
3. Abbreviations
EMF : Electromagnetic Field
ET : Electron Transfer
ROS : Reactive Oxygen Species
AO : Antioxidant
OS : Oxidative Stress
EOG : Electro-Olfactogram
DM : Dipole Moment
1. Introduction
Recent reviews provide extensive evidence for the importance of electrochemistry in living organisms. Electromagnetic Fields (EMFs) played an early role in living systems, as well as subsequent evolution [1]. The more recent literature on electrochemistry is documented, as well as magnetism. The large numbers of reports on interaction with living systems and the consequences are presented. An important aspect is involvement with cell signaling and resultant effects in which numerous signaling pathways participate. Much research has been devoted to the influence of man-made-EMFs e.g., from cell phones and electrical lines, on human health. The degree of seriousness is unresolved at present. The relationship of EMFs to Reactive Oxygen Species (ROS) and Oxidative Stress (OS) is discussed. There is evidence that indicates a relationship involving EMFs, ROS, and OS with toxic effects. Various articles deal with beneficial aspects of Antioxidants (AO) in countering the harmful influence from ROS-OS associated with EMFs. EMFs are useful in medicine, as indicated by healing bone fractures. Beneficial effects are recorded from electrical treatment of patients with Parkinson’s disease, depression, and cancer.
Electrochemistry and cell signaling are widely involved in the
operation of biochemical systems. A review [2]
discusses the relationship of the two, as well as interconnection with a
variety of other aspects, such as free radicals, receptors, and
stereochemistry. Both endogenous and exogenous agents are involved. The
electrochemistry deals with electrostatics, electron transfer, reduction
potentials, as well as involvement in membranes, proteins and neurotransmission.
Application of electrostatics is made to cell signaling involving
receptor-ligand action, phosphates, sulfates, metal cations, and miscellaneous
others. Apparently, energetics play a significant part. Practical and
experimental aspects are addressed.
The literature reveals an extensive involvement of electrostatics in biological systems [3]. In prior articles, supporting evidence was cited from volatile anesthetics, electron transport in photosynthesis and molecular electrostatic potential studies with DNA. The main focus is on energetics associated with bio-electrostatics. Examples include action of enzymes, such as, xylose isomerase, SOD and cytochrome c oxidase. In the membrane area, reports deal with the phospholipase-membrane and the nuclear membrane. Other categories are chromosomes, oxidation by hydroxyl radicals, Hofmeister effect, and histamine. In addition, electrostatic effects have been examined in the plant kingdom. There is relevant related material [4-9].
This report is unique in dealing in a unifying manner with electrochemical involvement in all senses, with application already made to smell [10] and taste [11]. Thus, the unifying aspect is novel in connection with touch, vision and hearing. Considering all of the senses, smell and taste differ from the others in that molecules initially participate. It is interesting that, with this difference, there is appreciable literature dealing with electrochemical effects in touch, vision and hearing.
It is important to recognize that biological action is often multifaceted with various factors participating. A good example is smell in which extensive literature exists dealing with operation of vibration and shape, in addition to electrochemistry [10]. Other important aspects are cell signaling, receptors and redox.
1.1. Odor
One of the main sense areas that receive extensive evidence for involvement of electrochemistry is odor. A recent review presents the various mechanistic aspects, which are summarized in the following four parts [10].
Part A shows that a correlation exists between odor and molecular dipoles, but of a limited nature. Compounds, such as hydrogen, nitrogen and oxygen, with no dipoles have no odors, in accord with the theoretical framework. Chlorine reacts rapidly at the receptor to produce odorous material. Alkanes have small Dipole Moments (DMs) e.g., propane (DM=0.08) [12] and relatively weak odors. Natural gas (methane) is diluted with strong odorant in order to aid leak detection. On the other hand, common perfumes contain functional groups (aldehyde, ketone, esters and nitrile) possessing higher DM values (1.75-3.92). However, this relationship alone is not sufficient in rationalizing the experimental data. A criticism of both Vibration and Electrochemistry theories is that vibrational energies can be small as in the case with some Dipole Forces (DFs) of odorant molecules. Is there sufficient energy to produce the observed result? Electrostatic forces can be relatively weak for dipoles, but stronger for ions. A recent study provides evidence for participation of small forces [13].
Part B deals with interaction of the odorant EF with those of the protein receptor. It is evident that the EFs alone of molecules are insufficient to rationalize the experimental observations. However, docking of the molecule into the receptor site brings the molecule EFs in contact with EFs of the receptor protein. There are many protein EFs of varying strengths associated with the numerous functionalities present. Some of the functional groups possess strong EFs, as with the ions derived from acidic and basic amino acids. The most prevalent dipole and a strong one (DM=3.68) is that of the peptide (amide) bond. Alterations can occur with interactions of dipoles or ions in the receptor, hydrogen bonding, ion formation with volatile acids and bases and covalent bonding. Thus, molecules with identical DMs and EFs can have different odors since binding to different receptors results in different EFs due to varied alterations. The important aspect of change in the strength of the odorant molecule EF field has received scant attention previously. There is considerable information concerning the olfactory receptors [10]. The altered EF then propagates the sequence by interaction with neurons in the olfactory system.
Part C comprises interaction of the receptor-ligand dipoles with olfactory neurons [10]. Various electrochemical interactions occur entailing the altered receptor-odorant EF and the neuronal system.
Research quite relevant to the electrochemical approach involves Electro-Olfatograms (EOGS) which reflect electrical potentials of the olfactory epithelium that occur in reference to the olfactory stimulation [14]. The EOG represents the sum of the generator potentials of olfactory receptor neurons. This approach has been used extensively with animals, together with much lesser application to humans. A review outlines the following: (a) the cellular and physiological nature of EOG response, (b) odor selection and delivery and (c) application of EOG in humans, fish and insect olfaction and pheromonal responsivity [15].
An article discusses molecular mechanisms of smell and taste [16]. Emphasis is on the transformation into electrical signals. This important contribution, which has received scant attention, adds credibility to the electrochemical theme. In the initial process of chemoreception, a stimulatory substance absorbs onto a membrane. The olfactory cells are primary sensory cells connected to the end of the olfactory nerve, and they depolarize when a stimulating substance absorbs in a receptive membrane. Hence, an impulse is generated directly from the nerve without involvement of synapse. The olfactory nerves can be viewed as information converters for changing chemical information into electrical signals. Therefore, a large resting potential which is negative inside the cell is produced. An appreciable amount of attention has been paid to exposure of the olfactory system to external electrical stimulus. The results are in accord with an electrochemical approach to olfactory action [10]. Although the electrical stimulus and the odor molecule both provide electrochemical force, the stimulus is different in having mobile electrons as the source. Also, interaction of the external stimulus with the olfactory nerve is not the same as for the odor molecule.
The above important investigations clearly demonstrate the participation of bio electrochemistry in the olfactory process entailing response to binding with the receptor.
Part D completes the sequence by transfer of information from Part C to the brain [10]. Since the brain is replete with electrochemical activity, it is not surprising that extensive, relevant literature pertains to the olfactory cortex [17]. This part of the cerebrum receives sensory input from the olfactory bulb. The events cause the membrane charge to become more positive, or depolarize, which travels down the axon of the olfactory receptor cells to the olfactory nerve. There is considerable literature documenting electrical effects in the cerebral olfactory cortex.
1.2. Other aspects
It is well established that ET processes play important roles in biology and medicine [18]. The negative electron in motion creates an electric field that can interact with others. Reviews discuss involvement of ET with receptor binding [5,18]. Hence, one can imagine participation of ET in the electrochemical phenomena taking place in the olfactory system. A book also touches upon the aspect [19]. ET commonly occurs in the receptor protein [18]. The role played by EFs, such as those associated with the dipolar peptide bond, is discussed. The ions and positive or negative dipoles interact with the negative electron involved in ET.
Cell signaling (signal transduction) plays an important role in biology and medicine, in which there is involvement of electrochemical effects [1-9]. Animals, including humans, can be regarded as complex electrochemical systems which evolved over billions of years. Organisms interact with and adapted to an environment of electrical and magnetic fields. Humans are now immersed in a man-made atmosphere of such fields whose long-term effects are unknown. The reviews provide much evidence linking cell signaling with electrical effects, including ET. There is considerable literature dealing with electrochemical effects associated with cell signaling in the olfactory system, providing further support for the theoretical framework.
Zinc has been implicated in several of the theoretical frameworks. A role for binding to zinc was outlined in the Vibration theory approach [20]: “The involvement of zinc in or near the active site of the olfactory receptor might account for the anomalous strength of certain classes of odorants. Thiols, nitriles and isonitriles, some of which are among the strongest odorants known, coordinated to zinc readily. Indoles bind to zinc and are very strong odorants, as are oxathianes, diketones. and furanones. Binding of these molecules to the zinc ion at or near the electron tunneling site will increase their effective concentration at the receptor and, all other things being equal, allow their detection at lower partial pressures.”
Zinc involvement can also be accommodated within the electrochemistry
framework [7], The review addresses an
electrostatic mechanism for metals cations in receptors and cell signaling.
Important involvement of bioelectrical effects in olfaction had previously been
recognized [1]. There are proposals linking odor
and taste mechanistically [10,16].
Other modes of action have been the center of attention, namely shape and vibration of the odorant [19-21]. Although shape has lost favor in recent years, there can be no doubt that it plays an important role in receptor binding, namely the well known “Lock and key” concept. The vibration debate continues [22] involving both pro [23] and con [24] evidence. There are more recent reports on the controversy [25,26].
1.3. Taste
This portion represents a highlight of a recent review on the mechanism of taste based on electrochemistry, receptors and signal transduction [11]. The mode of action is similar to that presented in the prior section on smell.
1.3.1. Part A. Tastant Molecules and Electromagnetic Fields (EFs): Limited Correlation
There is some correlation between molecular dipoles with associated EFs, and taste. Molecules with no dipoles, such as hydrogen, oxygen and nitrogen exhibit no taste. Appreciable Dipole Moments (DMs) [27] are linked to substances in the main taste classes. For example, in the case of sour taste, acetic acid (vinegar) has DM of 1.70. The data for sweetness are as follows: sugars, e.g., sucrose (alcohols 1.58-1.69 DM; aldehyde, 2.75 DM; ketone 2.88 DM; ether 1.10 DM; amine, 1.19 DM; amide, 3.68 DM; ester, 1.72 DM; toluene, 0.27 DM), higher DMs are limited to quinine (bitter taste), salty taste (NaCl), and ionic acids and bases.
1.3.2. Part B. Interaction of Tastant Molecule EF with Receptor EFs
Interaction of the tastant as ligand with the receptor plays an important role. It is evident that the EFs alone of molecules are insufficient to rationalize the experimental observations. However, docking of the molecule into the receptor site brings the molecular EFs in contact with EFs of the receptor protein. There are many protein EFs of varying strengths associated with numerous functionalities present. Some of the functional groups possess strong EFs, as with the ions derived from acidic and basic amino acids. The most prevalent dipole and stronger one (DM-3.68) is that of the peptide (amide) bond. Alterations can occur with interactions of dipoles or ions in the receptor, hydrogen bonding, ion formation with acids and bases and covalent bonding. Thus, molecules with identical DMs and EFs can have different taste since binding to different receptors result in different EFs due to varied alterations. The important aspect of change in the strength of the tastant molecule EF field has received scant attention previously. The altered EF then propagates the sequence by interaction with neurons in the olfactory system.
1.3.3. Part C. Receptors, Electrochemistry, Cell Signaling and Nerves
A 1984 book provides general fundamentals and also includes some of the rudimentary aspects of the electrochemical theory [28]. The structural basis of taste discrimination must be sought in all probability at a molecular level of receptor organization. Pfaffmann and his colleagues pioneered the electrophysiology of taste [11]. They recorded the neural responses of taste receptors to various chemical stimuli and found that individual nerve fibers showed responses to two or more types of stimuli. A taste bud consists of a cluster of cells many of which have intimate connections with nerve endings. The taste buds are possible taste receptor cells since they have extensive contacts with five nerve processes. At least two of these are taste receptor cells.
The AH, B theory was advanced in order to rationalize the sweet taste [11]. The hydroxyl groups, common in sugars, comprise the AH portion. Very close to hydrogen, there must exist another electronegative atom (B), such as O or N. The gap between the hydrogens and B is crucial. The AH, B grouping is necessary for the locking together of the sweet tastant molecules and the membrane receptor. The theory also rationalizes other sweet substances based on the AH, B pattern. A protein, bound to the membrane, is the tastant receptor. Evidently all sweet stimuli act by a common receptor mechanism.
A 1984 article provides information that is highly relevant to the electrochemical approach [29]. The gustatory cells in vertebrates are secondary sensory cells that are formed by the differentiation of epithelial cells, and are connected to the gustatory nerve via a chemical synapse. A stimulating substance adsorbs onto a microbilimembrane. As a result, the potential of the gustatory cell is changed into the direction of depolarization, and the conductor is discharged. The conductor acts on the end of the gustatory nerve to produce an impulse. The gustatory nerves are information converters for changing chemical information into electrical signals. If a stimulant is given to gustatory cells, a potential change in the direction of depolarization takes place. A large resting potential which is negative inside the cell is produced. If the nerve is stimulated, the sodium channel opens and ions outside flow inside. Opening of the channel greatly lowers membrane resistance. The potential change makes the inside more positive. The receptor potential of the gustatory cell is fundamentally the same as that of the olfactory cells. The membrane potential change occurs in the presence of various types of stimulants. When a stimulant is absorbed on the surface of gustatory cells, the membrane potential changes. There is change in membrane conformation resulting in alteration in the arrangement of charge transfer complexes and dipoles of the membrane resulting in change of membrane potential. This change is propagated by electrons to the synapse region or impulse generating position. The membrane depolarization is propagated to a synaptic gap and the potential-dependent calcium channel is activated. The calcium flow into gustatory cells result in discharge of norepinephrine.
Roper has contributed to cell signaling, neural involvement and other aspects [30-38], as has Kinnamon [39-48]. There are numerous other reports dealing with electrochemical effects in this connection [11]. A recent review deals with receptors that have been identified for various tastes [49]. Many other reports involve signal transduction [11].
1.3.4. Part D. Brain function
Subcortical connections route incoming signals from the receptors to brain stem regions, such as the medulla and cerebellum [28]. Higher vertebrates may respond to taste in two disparate ways. Evidence suggests that frontal brain electrical activity reveals asymmetries in activation in responses to taste stimuli [50]. Findings indicated that the electrical effect is present at birth. Other pertinent information in this category is available [11].
Investigations of electrical taste have been made. Electric taste may be described as the perception of a taste produced by passing a small current through the tongue [51]. The response profiles indicate a ion specificity for electric taste. The electrochemical theory derives strong support from the many studies that associate electrochemistry with taste.
1.4. Touch
This sensory perception mainly deals with the skin. Since evidence indicates involvement of electrochemistry in the other senses, it is reasonable to assume the possibility of participation in the sense of touch. The act of touch induces transmission of an impulse in the nervous system to the brain. There are reports on a role for electrochemistry, although this aspect has attracted little attention.
A crude hypothesis for ET involvement in neurotransmission was advanced in 1983 [52]. Later, electron translocation brought about by redox reactions was visualized as being the primary mechanism whereby electric fields are generated in the living cell [53]. Fast movement of electrons results in polarization, which establishes an electrical gradient. Electron migration conceivably progresses by means of radical intermediates. In 1996, the ET concept was applied to regulatory action of NO in neurotransmission, toxicity, and immunological reactions [54].
A 2004 review summarizes the present status of electrophysiological effects, and deserves special attention [55]. After a burst of research dealing with electrical coupling, gap junctions became less popular among the neurobiologists vs. the ionic approach. Recent reports have brought gap junction back into the spotlight, suggesting that this type of cell-cell signaling may be interrelated with, rather than an alternative to, chemical transmission. The thesis is credible because the electromagnetic effects of electrons and radicals in motion should have an influence on positive and negative charges associated with the Central Nervous System (CNS).
The generally accepted view of neurotransmission entails movement of ions in channels and gap junctions. This movement results in establishment of an electrical field. However, this aspect has attracted scant attention. The presence of these fields could well play a role.
A report deals with electrical stimulation of the skin [56]. When a sensor contacts the skin, an electrical stimulation translates the acquired information into a tactile sensation, such as pressure or vibration. In relation to skin receptor types, there are four mechanoreceptors, namely Meissner corpuscles, Merkel cells, Ruffini endings and Pacinian corpuscles. An electrical current from surface electrodes generates an electrical field inside the skin, inducing nerve activity. If the current flows from a central electrode, acting as an anode, it elicits an acute vibratory sensation. A cathodic pulse seems to selectively stimulate nerve fibers connected to Merkel cells, whereas an anodic pulse activates nerve fibers connected to Meissner corpuscles. Electrophysiological studies support this selective stimulation. Mathematically, analysis of a nerve-fiber electrical model revealed that a cathodic pulse selectively stimulates nerve axons running parallel to the skin’s surface, whereas an anodic pulse efficiently stimulates vertical oriented nerves.
Various studies are reported on electrical stimulus of the skin. An example is the effect of pulse height and pulse width on the magnitude sensation of electrocutaneous stimulation [57]. Experiments were performed to determine the relationship between the pattern of stimulus of nerves and the size of action potentials in frog’s skin [58]. The stimulating effect was determined of electric alternating impulses on the skin sensitivity of man [59]. An electrochemical stimulator system was used for neurophysiological and psychophysical studies of pain involving the skin surface [60]. A survey was performed comprising electrical stimulation of sensory nerves with skin electrodes for research, diagnosis, communication and behavioral conditioning [61]. Exposure to oscillating magnetic fields influences sensitivity to electrical stimuli of the skin [62]. Weak alterations of the magnetic field may induce hyperalgesis in humans. Frequency-related effects were determined in the optimization of magnetic stimulation of the nervous system in the skin [63]. Changes were identified in human skin electrical properties due to long-term neuromuscular electrical stimulation [64]. Intermittent stimulation delays adaptation to electrocutaneous sensory feedback [65]. The effect of stimulation waveform on pattern perception was investigated on a fingertip electrocutaneous display [66]. Data show that electrovibratory perceptual sensitivity to positive electrical pulses is less than that for negative pulses [67]. The disparity may be due to the asymmetric electrical properties of human skin. A study was made of pulse electrical stimulation on cells involving skin wound healing [68]. A report deals with vulnerability of skin to electric current perception [69]. This susceptibility condition to various exogenous factors suggests the intervention of neuropeptides and other neurobiological mediators.
1.5. Vision
1.5.1. Rhodopsin
Electrical phenomena may be found operating in the rhodopsin portion of the eye. Neural ectopic wiring in retinal degeneration, such as retinitis pigmentosa, may form functional synapses between cones and rod bipolar cells that cause atypical signal processing [70]. In a study, the multifacial Electroretinography (ERG) of an animal model, the rhodopsin P347L transgenic pig, were measured to examine the source and nature of altered signal processing. A report deals with ERG changes along with rhodopsin content in the isolated retina and eye cup of rats during retinal degeneration [71]. A comparison was made of electrically evoked and channel rhodopsin-evoked postsynaptic potentials in the pharyngeal system of Caenorhabditis elegans [72]. A report deals with rhodopsin and the electrical activity of the retina in congenital night blindness [73]. In a study of rhodopsin, a link appears to exist between chemical and electrical processes following light absorption [74]. An electrical approach was used to investigate rhodopsin activation [75]. The electrical properties of proton pumping rhodopsin have been examined [76]. Electrostatic interactions appear to play a critical role in rhodopsin activations [77]. There appears to be electric-field control of the bacteriorhodopsin photocycle, which has functional relevance [78].
There are other relevant aspects in the biochemistry of vision. Much attention has been devoted to light-induced cis-trans isomerization of the photosensitive rhodopsin. However, evidence also supports the involvement of ET and electrical phenomena. Upon photoexcitation of the chromophore, energized electron density in the highly unsaturated retinal chain is redistributed to the iminium end, causing a variety of events including cis-trans isomerization. The phenomena have been designated sudden polarization [79,80]. The evidence, including theoretical studies, points to a fundamental role in the initial stage of the visual process for ET in the retinal iminium moiety of rhodopsin. Electron migration of the negative charge cancels the positive charge on nitrogen. The generated radical cation on the retinal portion is delocalized. More than 30 years ago, the suggestion was made that this polarization is a crucially primary event in the overall mechanism leading to vision. Movement of electrons and positive charges during photo-induced ET is equivalent to establishment of an electrical current. The electrical signal triggered by light may, in turn, bring about a change in ion permeability of the disk membrane.
In most cases of ET, the process is intermolecular, in contrast to the intramolecular nature for rhodopsin. Establishment of the carbocation and loss of charge on nitrogen necessitate adjustments involving counterions. Electrostatic interactions were noted between electron deficient sites in the chromophore and charged or dipolar groups in the opsin [81]. The negative point charges were located near delocalized positive regions at C-12 and C-14.
1.5.2. Eye Illnesses
There is widespread participation of electrochemistry in eye insults. Electroretinography (ERG) is valuable for evaluation of visual function of animal models [82]. Both naturally occurring, and genetically-manipulated animal models of human retinal and optic nerve diseases have been studied in this manner. ERGs have proven to be quite useful for investigating visual functions in animal models of these human eye diseases. A novel experimental technique involving spectral electrical impedance was used to examine eye ulcers in animals [83]. The method may be helpful in diagnosing ocular surface diseases, such as dry eye syndrome. In ERG studies, some patients with acute zonal occult outer retinopathy show symptomatic acute visual impairment in one eye only, but electrophysiological abnormalities in both eyes [84]. The technique of axonal electrovisiogram can be considered to involve a visual evoked potential capable of recording the electrical activity of the optic nerve and inner retina [85]. The method may be useful as an electrophysiological test in the diagnosis of neuroretinal diseases. Electrophysiological testing is the preferred tool for examination of functional visual loss following chemical eye burn [86].
Various investigations were carried out involving electrical stimulation of the eye. Electrical stimulus was used in a study of eye movements [87]. A report deals with intraoperative monitoring of visual function using cortical potentials after electrical epidural stimulation of the optic nerve in connection with tumor removal [88].
1.5.3. Macular Degeneration and Retinal Pigmentosa
There is increased risk of degenerative diseases that affect the retinal cells with increasing age. Age-related macular degeneration, the loss of cells in the macula-near the center of the retina, affects millions of people around the world. Symptoms start with loss of fine vision, but can lead to declining vision and ultimately blindness in many cases. Retinitis pigmentosa is a genetic disorder that primarily affects photoreceptors in the retina, leading to incurable blindness. Symptoms include decreased night vision, decreased peripheral vision, and decreased central vision. Electrical stimulation of the retina and other technological approaches have become increasingly researched areas for restoring vision [89-94]. A review deals with electrical stimulation of the retina using implantable microelectrode array [95]. In both types of defects, the retina stays intact, but the light sensing photoreceptors do not function. A potential solution to the problem is retinal prosthesis. The implant is placed beneath the retina to essentially replace photoreceptors with connection to electrodes and the nerve center [96-98]. In a second type, the implant is placed on the surface of the retina.
1.5.4. Facial Nerve Paralysis
Facial nerve paralysis is a common problem which is caused by Bell’s palsy, trauma, tumor compression, or infection. Patients with facial nerve paralysis lack control over important muscles involved in facial expression. Blinking, rapid closing and opening of the eye spread tears over surface of the cornea, which is a necessary function to keep the eyes lubricated. Electrical stimulation in eyelid reanimation was shown to be potential treatment for facial nerve paralysis [99].
This portion is also relevant to electrochemical involvement in illnesses.
1.6. Hearing
Considerable research has been done on electrical involvement with hearing, much of which deals with electrical stimulation. The general participation of electrical phenomena in the CNS, discussed in the Touch section, is also applicable to the auditory nerve. There is appreciable literature dealing with electrical stimulation of the ear which suggests a role for electrochemistry on operation. Also, there is a unifying theme since the technique has been used in the study of other senses, particularly smell and taste (see earlier sections).
Electrical stimulation of the cochlea is known to cause auditory sensations in humans and other animals [100]. It has been shown to produce emissions of sound from the inner ear. The relationship between electrically induced motion of the Basilar Membrane (BM) and production of otoacoustic emissions was studied. The hypothesis was tested that electrical current-induced movements of the Outer Hair Cell (OHC electromotility) result in intracochlear acoustic pressure which causes traveling waves on BM. Results provide direct support for a mechanism of cochlear sensitivity and tuning involving high-frequency OHC electromotility. Moreover, the data also indicate that any intra- or extracochlear electric current which affects the electric polarization of OHCs could induce BM traveling waves and cause ‘Electronic hearing’. This form of hearing would be one component under the more general definition of the electophonic effect.
Application of electric stimulation to the cochlea induces an acoustic emission in the ear canal [101]. These emissions are produced by basilar membrane motion, and have been used to suggest a corresponding acoustic sensation termed “Electromotile hearing” which has been attributed to electric stimulation of Outer Hair Cells (OHCs) in the organ of Corti. Electric stimulation of the cochlea results in perception of a tonal sound at a frequency of 8 Hz or above. Mammalian OHCs convert electrical energy into mechanical energy [102]. The significance of this electromotility rests in the ability of the OHCs to modulate the vibrations of the cochlea partition in vivo. Electrical stimulation of the guinea pig cochlea induces a mechanical response of the basilar membrane for frequencies to at least 100 kHz. The OHCs play a critical role in mammalian hearing [103]. OHCs enhance basilar membrane motion through a mechanical feedback process within the cochlea, called the cochlear amplifier. The basis of the cochlear response is believed to be a voltage-dependent electromotile factor. This response to sound stimulation appears to enhance the sensitivity and selectivity of the cochlea [104]. These OHC mechanical changes feed energy back into the cochlea before completion of the transduction process by the inner hair cells. OHC electromotility may depend on certain transmembrane proteins. The electromotile response is thought to underlie the sharp tuning and sensitivity of the mammalian inner ear, and contributes to the production of Electrically Evoked Otoacoustic Emissions (EEOAEs) [105]. Results suggest a biological origin of the EEOAE in the cochlea, which could involve electrically-evoked stereocilia bundle movements. The OHCs of the cochlea have an electromotility mechanism, based on conformational changes of voltage-sensitive motor proteins in the lateral plasma membrane [106]. The translocation of electrical charges across the membrane during electromotility induces a voltage dependency to the membrane capacitance. Two different calcium-dependent pathways may control the OHC motor output. One route shifts the voltage sensitivity of the OHC electromotile mechanism. A salient feature of peripheral sound processing in the mammalian cochlea is high-frequency resolution [107]. The sensitivity originates in amplification of the wave on the basilar membrane by OHCs, where electrically induced mechanical action of the OHCs is believed to be the crucial component. The electromechanical process of the OHCs possesses the ability to bring about amplification of the traveling wave. The OHCs are believed responsible for the high sensitivity and selectivity of mammalian hearing [108]. Molecular motion appears to cause the electrically-driven length change (electromotility) of the OHCs.
Electrokinetic effects might also play a role. A study showed that chlorpromazine in large doses may decrease hearing or otoacoustic emissions [109]. In the process OHCs electromotility is altered. In the mammalian cochlea, the basilar membranes mechanical responses are amplified, and frequency tuning is sharpened through feedback from the electromotile OHCs [110]. OHCs undergo elongation-contraction cycles when stimulated by electricity [111]. This electromotile response is believed to underlie the high sensitivity and frequency selectivity of amplification in mammalian cochlea. In an investigation of OHC electromotility, DC electrical pulses either elongate or shorten the cell and electrical stimulation results in mechanical oscillations [112]. Cell turgor is required so that pressure gradients associated with the electromotile responses can be communicated to the ends of the cell. Loss in cell turgor lessens the electromotile response. Basilar membrane vibrations induced by direct current are similar to those brought about by acoustic stimulation, which can transfer to other organ parts by traveling waves [113]. The electromotile properties of OHCs contribute largely to hearing sensitivity and frequency selectivity, leading to generation of otoacoustic emissions [114]. Cochlea OHCs in humans showed electromotility in voltage steps similar to that in rodent models [115]. Electrically evoked oto-acoustic emissions are sounds evoked in the canal when AC current is led into the cochlea [115]. The result is attributed to activation of fast electromotile responses in OHCs. Acoustic enhancement occurs when the emission amplitude is increased by moderate-level sound. A report deals with the radial pattern of basilar membrane motion evoked by electric stimulation of the cochlea [116]. There are related reports on electrochemistry [117-122].
The literature contains other reports dealing with hearing and
electrical effects. Electropuncture therapy is used for sudden hearing loss [123] and in chronic pain patients [124]. Research was done on inner ear metabolism and
electrical physiology of autoimmune sensoneural hearing loss [125]. A stochastic model was used for electrically
stimulated auditory nerve pulse-train response [126].
A study involved the effects of electric stimulation on the electrically evoked
compound action potential [127].
Electrophysiological evidence was obtained for “Streaming” in auditory evoked
potentials [128]. An investigation dealt with
changes in speech with electric sound amplification [129].
Electrophysiological evidence exists for response priming and conflict
regulation that are consistent with an information processing model [130]. Loudness-coding mechanisms were inferred from
electric stimulation of the human auditory system [131].
Results indicate that, as suggested by depolarization models, in vivo
electrical stimulation-mediated neuroprotection requires the activation of
voltage-gated calcium channels [132]. Electrophysiological
evidence is reported for prefrontal cortex involvement in preattentive auditory
deviance detection [133]. Other
electrophysiological approaches suggest that the mismatch negativity is
generated by a temporofrontal network subserving preattentive auditory change
detection. A study was made to determine the usefulness of electrostimulation
in treatment of persistent noise-induced cochlea lesion tinnitus [134]. Low frequency acoustic and electric stimuli
produced similar auditory perceptions [135]. Electrocochleography
and auditory brain stem response were examined in relation to Ramsay Hunt
syndrome [136]. The exact mechanism by which the
basilar membrane movement excites the hair cells is the subject of lively
controversy and many theories [137]. It is
likely that bending or shearing movement of the hairs relative to the apex of
the cell induces a change in the difference in electrical charge between the
contents of the cell and its surroundings. This change, technically a
depolarization, will in turn stimulate the release of a chemical transmitter,
probably glutamic acid. The substance initiates nerve impulse in the sensory
nerve that has connections with the hair cells.
- Kovacic P, Somanathan R (2010) Electromagnetic
fields: mechanism, cell signaling, other bioprocesses, toxicity, radicals,
antioxidants and beneficial effects. J Recept Signal Transduct 30: 214-226.
- Kovacic P, Hall ME (2010) Bioelectrochemistry:
reactive oxygen species, receptors and cell signaling: how interrelated? J
Recept Signal Transduct 30: 1-9.
- Kovacic P (2008) Bioelectrostatics: Review of
widespread importance in biochemistry. J Electrostat 66: 124-129.
- Kovacic P, Pozos RS (2006) Cell signaling (mechanism
and reproductive toxicity): redox chains, radicals, relays, conduit,
electrochemistry, and other medical implications. Birth Defects Res 78: 333-344.
- Kovacic P, Pozos RS, Draskovich CD (2007) Unifying
electrostatic mechanism for receptor-ligand activity. J Recept Signal Transduct
Res 27: 411-431.
- Kovacic P, Draskovich CD, Pozos RS (2007) Unifying
electrostatic mechanism for phosphates and sulfates in cell signaling. J Recept
Signal Transduct Res 27: 433-442.
- Kovacic P (2008) Unifying electrostatic mechanism for
metal cations in receptors and cell signaling. J Recept Signal Transduct Res 28:
153-161.
- Kovacic P, Somanathan R (2008) Unifying mechanism for
metals in toxicity, carcinogenicity amd therapeutic action: integrated approach
involving electron transfer, oxidative stress, antioxidants, cell signaling and
receptors. J Recept Signal Tranduct 30: 51-60.
- Kovacic P (2009) Simplyfying the complexity of cell
signaling in medicine and the life sciences: radicals and electrochemistry. Med
Hypotheses 74: 769-771.
- Kovacic P (2012) Mechanism of
smell: electrochemistry, receptors, and cell signaling. J Electrostat 70: 1-6.
- Kovacic P (2012) Mechanism of
taste: electrochemistry, receptors and signal transduction. J Electrostat 70:
7-14.
- Lide DR (ed)
(2009-2010) Handbook of Chemistry and Physics, Ninetieth ed. CRC Press, New
York, pp 9-52 to 9-57.
- Arnaud C (2007)
Weak forces. Chem Engin News 85: 12.
- Knecht M, Hummel T (2004) Recording of the human
electro-olfactogram. Physiol Behav 83: 13-19.
- Scott GW, Scott-Johnson PE
(2002) The electroolfactogramm: a review of its history and uses. Micro Res
Tech 58: 152-160.
- Kurihara K
(1985) Molecular mechanisms of the senses of taste and smell: transformation of
chemical information into electrical signals. Kagaku 54: 669-678.
- Bear MF, Barry W (2007) Neuroscience: exploring the brain.
Williams and Wilkens, Baltimore, 1996, 200-207.
- Kovacic P, Pozos RS (2007)
Bioelectrome, integrated approach to receptor chemistry, radicals,
electrochemistry, cell signaling and physiological effects based on electro
transfer. J Recept Signal Transduct 27: 261-294.
- Burr C (2002)
The emperor of scent. Random House, New York, pp. 1-305.
- Turin L (1996) A spectroscopic mechanism for primary
olfactory reception. Chem Senses 21, 773-791.
- Turin L (2006) The secret of
scent. Harper Collins, New York, pp. 1-193.
- Haddad R, Lapid H, Harel D, Sobel N (2008) Measuring
smells. Curr Opin Neurobiol 18: 438-444.
- Brooks JC, Hartoutsiou F, Horsfield AP, Stoneham AM
(2007) Could humans recognize odor by phonon assisted tunneling. Phys Rev Lett
98: 38101-38114.
- Keller A, Vosshal LB (2004) A psychophysical test of
the vibration theory of olfaction. Nat Neurosci 7: 337-338.
- Rinaldi A (2011) Do vibrating
molecules give us our sense of smell? Science NOW Feb. 2011.
- Franco MI, Turin L, Mershin A, Skoulakis EMC (2011)
Molecular vibration-sensing component in Drosophila
melanogaster olfaction.
PNAS 108: 3797-3802.
- Haynes WM
(Ed.) (2010-2011) CRS Handbook of Chemistry and Physics, 91st. ed.
CRC Press, New York, 9-51 to 9-59.
- Whitfield P,
Stoddart DM (1984) Hearing, taste and smell: pathways of perception. (Human
body). Scribner, New York, Ch. 4 and 5, pp. 65-102.
- Kurihara OK
(1985) Molecular mechanisms of the senses of taste and smell: transformation of
chemical information into electrical signals. Kagaku 54: 669-678.
- Huang YA, Maruyama Y, Roper SD (2008) Norepinephrine
is coreleased with serotonin in mouse taste buds. J Neurosci 49: 13088-13093.
- Huang Y-J, Maruyama Y, Dvoryanchikov G, Pereira E,
Chaudhari N, et al. (2007) The role of pannexin 1 hemichannels in ATP release
and cell-cell communications in mouse taste buds. PNAS 104: 6436-6441.
- Huang Y-J, Maruyama Y, Lu LK-S, Pereira E, Chaudhari
N, et al. (2005) Mouse taste buds use serotonin as neurotransmitter. J Neurosci
25: 843-847.
- Caicedo A, Pereira E, Margolskee RF, Roper SD (2003)
Role of the G-protein subunit alpha-gustducin in taste cell responses to bitter
stimuli. J Neurosci 23: 9947-9952.
- Chaudhari N, Landin AM, Roper SD (2000) A metabotropic
glutamate receptor variant functions as a taste receptor. Nat Neurosci 3:
113-119.
- Dando R, Roper SD (2009) Cell-to-cell communications
in intact taste buds through ATP signaling from pannexin 1 gap junction
hemichannels. J Physiol 587: 5899-5906.
- Huang YA, Dando R, Roper SD (2009) Autoceine and
paracrine roles for ATP and serotonin in mouse taste buds. J Neurosci 29:
13909-13918.
- Roberts CD,
Dvoryanchikov G, Roper SD (2009) Interaction between the second messengers cAMP
and Ca2b in mouse presynaptic taste cells. J Physiol 587: 1657-1668.
- Kinnamon SC, Roper SD (1987)
Voltage-dependent ionic current in dissociated nudpuppy taste cells. New York
Acad Sci XII: 413-416.
- Trubey KR, Culpepper S, Maruyama Y, Kinnamon SC,
Chaudhari N (2006) Tastants evoke cAMP signal taste buds that is independent of
calcium signaling. Am J Physiol Cell Physiol 291: C237-C244.
- Vandenbeuch A, Tizzano M,
Anderson CB, Stone LM, Goldberg D, et al. (2010) Evidence for a role of
glutamate as an efferent transmitter in taste buds. BMC Neurosci 11: 1-7.
- Clapp TR, Medler KF, Damak
RFS, Margolskee RF, Kinnamon SC (2006) Mouse taste cells with G protein-coupled
taste receptors lack voltage-gated calcium channels and SNAP-25. BMC Biology 4:
1-9.
- Finger TE, Danilova V, Barrows J, Bartel DL, Vigers
AJ, et al. (2005) ATP signaling is crucial for communication from taste buds to
gustatory nerves. Science 310: 1495-1499.
- Clapp TR, Yang R, Stoick CL, Kinnamon SC, Kinnamon JC
(2004) Morphologic characterization of rat taste receptor cells that express
components of the phospholipase C signaling pathway. Journal of Compreh Neurol
468: 311-321.
- Medler KF, Margolskee RF, Kinnamon SC (2003)
Electrophysiological characterization of voltage-gated currents in defined
taste cell types of mice. J Neurosci 23: 2608-2617.
- Mackay-Sim A,
Delay RJ, Roper SD, Kinnamon SC (1999) Development of voltage-dependent
currents in taste receptor cells. J Compreh Neurol 365: 278-288.
- Cummings TA, Daniels C, Kinnamon SC (1996) Sweet
taste transduction in hamster: sweeteners and cyclic nucleotides depolarize
taste cells by reducing K+ current. J Neurophysiol 75: 1256-1263.
- McPheeters M,
Barber AJ, Kinnamon SC, Kinnamon JC (1994) Electrophysiological and
morphological properties of light and dark cells isolated from mudpuppy taste
buds. Journal of Comprehensive Neurology 346: 601-612.
- Kinnamon SC, Ropee SD (1988) Membrane properties of
isolated mudpuppy taste cells. Journal of General Physiology 91: 351-371.
- Barham P, Skibsted LH, Bredie LP, Frost MB, Moller J,
et al. (2010) Molecular gastronomy: a new emerging scientific discipline. Chem
Rev 110: 2313-2365.
- Fox NA, Davidson RJ (1986) Taste-elicit changes in
facial signs of emotion and the asymmetry of brain electrical activity in human
newborns. Neurophysiol 24: 417-422.
- Herness MS (1983)
Neurophysiological and biophysical evidence concerning the mechanism of
electric taste. Ph. D. Thesis, The Florida State University.
- Kovacic P, Jacintho JD (2003) Neurotransmission and
neurotoxicity by nitric oxide, catecholamines, and glutamate: unifying themes
of reactive oxygen species and electron transfer. Curr Med Chem 10: 2693-2704.
- Berry MN,
Grivell AR, Wallace PG (1985) In Srinivasan S, et al. (Eds.) Comprehensive
Treatise in Electrochemistry, Plenum, New York, pp. 347-380.
- Kovacic P
(1996) Electron transfer mechanism for regulatory action by nitric oxide.
Biolectrochem Bioenerg 39: 155-159.
- Hormuzdi SG, Filippov MA, Mitropoulou G, Monyer H,
Bruzzone R (2004) Electrical synapses: a dynamic signaling system that shapes
the acvtivity of neuronal networks. Biochim Biophys Acta 1662: 113-137.
- Kajomoto H, Kawakami N, Tachi S (2004) Smart touch:
electric skin to touch the untouchable. Comput Graph Appl 24: 36-43.
- Tachi S, Tanie K, Abe M (1977) Effects of pulse
height and pulse width on the magnitude sensation of electrocutaneous stimuli.
Iyodenshi To Seitai Kogaku 15: 315-320.
- Wakabayashi T, Satow Y, Osumi
T (1975) Pattern stimulation and action potential of frog skin. Nihon Seirigaku
Zasshi 37: 411-421.
- Eltahir K
(1965) Stimulating effect of rectangular electric alternating impulse on the
skin sensitivity of man. Gildemeister effect. Acta Biol Med Ger 15: 597-607.
- Schneider W, Slugg RM, Turnquist BP, Meyer RA,
Campbell JN (1995) An electromechanical stimulator system for
neurophysiological and psychophysical studies of pain. J Neurosci Methods 60:
61-68.
- Pfeiffer EA (1968) Electrical
stimulation of sensory nerves with skin electrodes for research, diagnosis,
communication and behavioral conditioning: a survey. Med Biol Eng 6: 637-651.
- Papi F, Ghione S, Rosa C, Del Seppia C, Luschi P
(1995) Exposure to oscillating magnetic fields influences sensitivity to
electrical stimuli. Experiments on humans. Bioelectromagnetics 16: 295-300.
- Ravazzani P, Ruohonen J, Tognola G, Anfosso F,
Ollikainen M, et al. (2002) Frequency-related effects on the optimization of
coils for the magnetic stimulation of the nervous system. IEEE Trans Biomed Eng
49: 463-471.
- Bîrlea SI, Bîrlea NM, Breen PP, O’Laighin G (2008)
Identifying changes in human skin electrical properties due to long-term
neuromuscular electrical stimulation. Conf Proc IEEE Eng Med Biol Soc: 326-329.
- Buma DG, Buitenweg JR, Veltink
PH (2007) Intermittent stimulating delays adaptation to electrocutaneous
sensory feedback. IEEE Trans Neural Syst Rehabil Eng 15: 435-441.
- Kaczmarek KA, Haase SJ (2003) Pattern idenfication
and perceived stimulus quality as a function of stimulation waveform on a
fingertip-scanned electrotactile display. IEEE Trans Neural Syst Rehabil Eng 11:
9-16.
- Kaczmarek KA, Nammi K, Agarwal AK, Tyler ME, Haase
SJ, et al. (2006) Polarity effect in electrovibration for tactile display. IEEE
Trans Biomed Eng 53: 2047-2054.
- Cheng K, Tarjan PP, Mertz PM (1993) Theoretical study
of rectangular pulse electrical stimulation (RPES) on skin cells (in vivo)
under conforming electrodes. Biomed Sci Instrum 29: 349-354.
- Quatresooz P, Piérand-Franchimont C, Piérand GE
(2009) Vulnerability of reactive skin to electric current perception: a pilot
study implicating mast cells and the lymphatic microvasculature. J Cosmet
Dermatol 8: 186-189.
- Ng YF, Chan HH, Chu PH, To CH, Gilger BC, et al.
(2008) Multifocal electroretnogram in rhodopsin p347L transgenic pigs. Invest
Opthalmol Vis Sci 49: 2208-2215.
- Govardovskiǐ VI, Ostapenko IA, Shabanova ME, Fuks BB, Etingof RN (1977) Changes in
the electroretinogram and concentration of rhodopsin in the Hunter strain of
rats during development of hereditary retinal degeneration. Neirofoziologiia 9:
527-531.
- Franks CJ, Murray C, Ogden D,
O’Connor V, Holden-Dye L (2009) A comparison of electrically evoked channel
rhodopsin-evoked postsynaptic potentials in the pharyngeal system of Caenorhabditis elegans. Invert Neurosci 9: 43-56.
- Carr RE, Ripps H, Siegel IM, Weale RA (1966)
Rhodopsin and the electrical activity of the retina in congenital night
blindness. Invest Opthalmol 5: 497-507.
- Buckser S,
Buckser DS (1971) On the structure of rhodopsin. IV. A link between the
chemical and electrical processes following light absorption. J Optom Arch Am
Acad Optom 48: 121-123.
- Sullivan JM, Brueggemann L, Shukla P (2000)
Electrical approach to study rhodopsin activation in single cells with early
receptor current assay. Methods Enzymol 315: 268-293.
- Hagedorn R, Gradmann D, Hegemann P (2008) Dynamics of
voltage profile in enzymatic ion transporters, demonstrated in electrokinetics
of proton pumping rhodopsin. Biophys J 95: 5005-5013.
- Ramon E, Cordomi A, Bosch L, Zernii EY, Senin II, et
al. (2007) Critical role of electrostatic interactions of amino acids at the
cytoplasmic region of helices 3 and 6 in rhodopsin conformational properties
and activation. J Biol Chem 282: 14272-14282.
- Rivas L, Hippler-Mreyen S,
Engelhard M, Hildbrandt P (2003) Electric-field decays of two spectroscopically
different M-states of photosensory rhodopsin II from Natronobacterium pharaonis. Biophys J 84: 3864-3874.
- Bonačič-Kouteckỳ V, Kouteckỳ
JA, Michl J (1987) Neutral and charged biradicals, zwitterions, funnels in S1,
and proton translocation: their role in photochemistry, photophysics, and
vison. Angew Chem Int Ed 26: 170-189.
- Salem L
(1979) The sudden polarization effect and its possible role in vision. Acc Chem
Res 12: 87-92.
- Sheves M,
Nakanishi K, Honih B (1979) Through-space electrostatic effects in electronic
spectra. Experimental evidence for the external point-charge model of visual
pigments. J Am Chem Soc 101: 7086-7088.
- Kondo M (2010) Animal models of human retinal and
optic nerve diseases analyzed using electroretinography. Nihon Ganka Zasshi 114:
148-178.
- Bellotti MI, Bast W, Berra A, Bonetto FJ (2011) A new
experimental device to evaluate eye ulcers using multispectral electrical
impedance technique. Rev Sci Instrum 82: 074303.
- Kure K, Obata R, Inoue Y,
Iriyama A, Yanagi Y (2011) Acute progression of electrophysiologically affected
Bellow eye in unilaterally symptomatic acute zonal occult outer retinopathy.
Clin Opththalmol 5: 1167-1170.
- Cella WP, Dantas AM, Lima AV, Avila MP (2011) Axonal
electrovisiogram as an electrophysiological test to evaluate optic nerve and
inner retina electrical potentials: findings in normal subjects. Arq Bras
Oftalmol 74, 37-43.
- Jiraskova N, Kuba M, Kremlacek
J, Rozsival P (2011) Normal sensory and absent cognitive electrophysiological
responses in functional visual loss following chemical eye burn. Doc
Opththalmol 123, 51-57.
- Davidovics NS, Fridman GY, Chiang B, Della Santina CC
(2011) Effects of biphasic current pulse frequency, amplitude, duration, and
interphase gap on eye movement responses to prosthetic electrical stimulation
of the vestibular nerve. IEEE Trans Neural Syst Rehabil Eng 19, 84-89.
- Benedičič M, Bošnkak R (2011) Intraoperative monitoring of the visual
function using cortical potentials after electrical epidural stimulation of the
optic nerve. Acta Neurochir (Wien) 153: 1919-1927.
- Dowling J (2005) Artificial
human vision. Expert Rev Med Devices 2: 73-85.
- Suzuki S, Humayun MS, Weiland JD, Chen S-J, Margalit
E, et al. (2004) Comparison of electrical stimulation thresholds in normal and
retinal degenerated mouse retina. Jpn J Opththalmol 48: 345-349.
- Shinoda K, Imamura Y, Matsuda S, Seki M, Uchida A, et
al. (2008) Transcutaneous electrical retinal stimulation therapy for
age-related macular degeneration. Open Opththalmol J 2: 132-136.
- Schatz A, Röck T, Naycheva L, Willmann, Wilhelm B,
Peters T, et al. (2011) Transcorneal electrical stimulation for patients with
retinitis pigmentosa: a prospective, randomized, sham-controlled exploratory
study. Invest Opththalmol Vis Sci 52: 4485-4496.
- Cai C, Ren Q, Desai NJ, Rizzo JF, Fried SI (2011)
Response variability to high rates of electric stimulation in retinal ganglion
cells. J Neurophysiol 106: 153-162.
- Sekirnjak C, Hottowy P, Sher A, Dabrowski W, Litke
AM, et al. (2006) Electrical stimulation of mammalian retinal ganglion cells
with multielectrode arrays. J Neurophysiol 95: 3311-3327.
- Walter P (2009) Implants for
artificial vision. Expert Rev Opththalmol 4: 515-523.
- Zhou DD, Greenberg RJ (2005) Microsensors and
microbiosensors for retinal implants. Front Biosci 10: 166-179.
- Onnela N, Takeshita H, Kaiho Y, Kojima T, Kobayashi
R, et al. (2011) Comparison of electrode material for the use of retinal
prosthesis. Biomed Mater Eng 21, 83-97.
- Palanker D, Vankov A, Huie P, Baccus S (2005) Design
of a high-resolution optoelectronic retinal prosthesis. J Neural Eng 2:
S105-S120.
- Chen K, Chen T-C, Cockerham K, Liu W (2009)
Closed-loop eyelid reanimation system with real-time blink detection and
electrochemical stimulation for facial nerve paralysis. IEEE Circuit System Int
Symposium 549-552.
- Nuttall AL, Ren T (1995) Electromotile hearing:
evidence from basilar membrane motion and otoacoustic emissions. Hear Res 92:
170-177.
- Le Prell CG, Kawamoto K,
Raphael Y, Dolan DF (2006) Electromotile hearing: acoustic tones mask
psychophysical response to high-frequency electrical stimulation of intact
guinea pig cochlea. J Acoust Soc Am 120: 3889-3900.
- Grosh K, Zheng J, Zou Y, de
Boer E, Nuttall AL (2004) High-frequency electromotile responses in the
cochlea. J Acoust Soc Am 115: 2178-2184.
- He DZZ, Jia S, Feng F (2003)
Thyroid hormone is not necessary for the development of outer hair cell
electromotility. Hear Res 175: 183-189.
- Le Grimellec C, Giocondi M-C,
Lenoir M, Vater M, Sposito G, et al. (2002) High-resolution three-dimensional
imaging of the lateral plasma membrane of cochlea outer hair cells by atomic
force microscopy. J Comp Neurol 451: 62-69.
- Chen L, Sun W, Salvi RJ (2001)
Electrically evoked otoacoustic emissions from the chicken ear. Hear Res 161:
54-64.
- Frolenkov GI, Mammano F,
Belyantseva IA, Coling D, Kacher B (2000) Two distinct Ca(2+)-dependent signaling pathways
regulate the motor output of cochlea outer hair cells. J Neurosci 20: 5940-5948.
- Frank G, Hemmert W, Gummer AW
(1999) Limiting dynamics of high-frequency electromechanical transduction of
outer hair cells. Proc Natl Acad Sci 96: 4420-4425.
- Jerry RA, Dutta A (1998)
Molecular motor and electrokinetic contributions to outer hair cell
electromotility. J Neurophysiol 79: 471-473.
- Lue AJ, Zhao HB, Brownell WE
(2001) Chlorpromazine alters outer hair cell electromotility. Otolaryngol Head
Neck Surg 125: 71-76.
- Nilsen KE, Russell IJ (1999)
Timing of cochlea feedback: spatial and temporal representation of a tone
across the basilar membrane. Nat Neurosci 2: 642-648.
- Dallos P, Evans BN (1995)
High-frequency motility of outer hair cells and the cochlea amplifier. Science
267: 2006-2009.
- Brownell WE (1990) Outer hair
cell electromotility and otoacoustic emissions. Ear Hear 11: 82-92.
- Guo M, Ren T, Nuttall Al
(1997) Research on basilar membrane vibration of guinea pigs elicited by direct
current pulse. Zhonghua Er Bi Yan Hou Ke Za Zhi 32: 259-263.
- Morlet T, Perrin E, Durrant
JD, Lapillonne A, Ferber C, et al. (1996) Development of cochlear active
mechanisms in humans differs between gender. Neurosci Lett 220: 49-52.
- Kirk DL, Yates GK (1998)
Enhancement of electrically evoked oto-acoustic emissions associated with
low-frequency stimulus bias of the basilar membrane towards scala vestibuli. J
Acoust Soc Am 104: 1544-1554.
- Nuttall AL, Guo M, Ren T
(1999) The radial pattern of basilar membrane motion evoked by electric
stimulation of the cochlea. Hear Res 131: 39-46.
- Shepherd RK, Baxi JH, Hardie
NA (1999) Response of inferior colliculus neurons to electric stimulation of
the auditory nerve in neonatally deafened cats. J Neurophysiol 82: 1363-1380.
- Szonyi M, He DZ, Ribari O, Szklai I, Dallos P (2001)
Intracellular calcium and outer hair cell electromotility. Brain Res 922,
65070.
- Zhang M, Kalinec GM, Urrutia
R, Billadeau DD, Kalinec F (2003) ROCK-dependent and ROCK-independent control
of cochlea outer hair cell electromotility. J Biol Chem 278, 35644-35650.
- Sziklai I, Toth T, Zimmermann
U (2003) The effects of auditory research on clinical practice. HNO 51, 456-461.
- Borko R, Batta TJ, Sziklai I (2005) Electomotile
performance of isolated outer hair cells during slow motile shortening. Acta
Otolaryngol 125, 547-551.
- Miller CA, Abbas PJ, Robinson
BK, Nourski KV, Zhang F, et al. (2006) Electrical excitation of the
acoustically sensitive auditory nerve: single-fiber response to electric pulse
trains. J Assoc Res Otolaryngol 7: 195-210.
- Luo RH, Zhou J, Huang YS, Xu K
(2009) Observation on therapeutic effect of electroacupuncture for treatment of
sudden hearing loss. Zhongguo Zhen Jiu 29: 185-187.
- Kumar A, Tandon OP, Dam S,
Bhattacharya A, Tyagi KK (1994) Brainstem auditory evoked response changes
following electro-acupunture therapy in chronic pain patients. Anaesthesia 49:
387-390.
- Tan C, Cao Y, Hu P (1998) The experimental research of
inner ear metanolism and electrical physiology of autoimmune sensorineural hearing
loss. Lin Chuang Er Bi Yan Hou Ke Za Zhi 12: 407-410.
- Bruce IC, Irlicht LS, white
MW, O’Leary SJ, Dynes S, et al. (1999) A stochastic model of the electrically
stimulated auditory nerve: pulse-train response. IEEE Trans Biomed Eng 46:
630-637.
- Nourski KV, Abbas PJ, Miller
CA, Robinson BK, Jeng FC (2007) Acoustic-electric interactions in the guinea
pig auditory nerve: simultaneous and forward masking of the electrically evoked
compound action potential. Hear Res 232: 87-103.
- Jones SJ, Longe O, Vaz Pato M
(1998) Auditory evoked potentials to abrupt pitch and timbre change of complex
tones: electrophysiological evidence of ‘streaming’? Electroencephalogr Clin
Neuropgysiol 108: 131-142.
- Jónsdottir V, Laukkanen AM,
Vilkman E (2002) Changes in teachers’ speech during a working day and without
electric sound amplification. Folia Phoniatr Logop 54: 282-287.
- Leuthold H, Schröter H (2006)
Electrophysiological evidence for respone priming and conflict regulation in the
auditory Simon task. Brain Res 1097: 167-180.
- Zeng FG, Shannon RV (1994)
Loudness-coding mechanisms inferred from electric stimulation of the human
auditory system. Science 264: 564-566.
- Miller AL, Prieskorn DM,
Altschuler RA, Miller JM (2003) Mechanism of electrical stimulation-induced
neuroprotection: effects of verapamil on protection of primary auditory
afferents. Brain Res 966: 218-230.
- Doeller CF, Optiz B,
Mecklinger A, Krick C, Reith W, Schröger E (2003) Prefrontal cortex involvement
in preattentive auditory deviance detection: neuroimaging and
electrophysiological evidence. Neuroimag 20: 1270-1280.
- Konopka W, Zalewski P,
Olszewski J, Olszewska-Ziaber A, Pietkiewicz P (2001) Tinnitus suppression by
electrical promontory stimulation (EPS) in patients wih sensorineural hearing
loss. Auris Nasus Larynx 28: 35-40.
- Edgerton BJ, Doyle KJ (1982)
Auditory perceptions induced by low-frequency acoustic and electric
stimulation. J Aud Res 22: 216-224.
- Kusakari J, Takeyama M, Kawase
T, Takahashi K, Sasaki Y, et al. (1988) Studies with electrocochleagraphy and
auditory branstem response in Ramsay Hunt syndrome. Acta Otolaryngol Suppl 446:
81-84.
- Whitfield P, Stoddart DM (1984) Hearing, taste, and
smell; pathways of perception. Torstar Books, New York, Ch 1: 33.
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