Enhancing saltiness with cathodal current

2013 ◽  
Author(s):  
Hiromi Nakamura ◽  
Homei Miyashita
Keyword(s):  
Cathodal Current

Generation and transit pathway of H+ is critical for inhibition of palmar sweating by iontophoresis in water

1993 ◽  
Vol 75 (5) ◽  
pp. 2258-2264 ◽  
Author(s):  
K. Sato ◽  
D. E. Timm ◽  
F. Sato ◽  
E. A. Templeton ◽  
D. S. Meletiou ◽  
...  
Keyword(s):  
Sweat Rate ◽  
Tap Water ◽  
Inhibitory Effect ◽  
Sweat Glands ◽  
Galvanic Current ◽  
Silicone Grease ◽  
Secretory Coil ◽  
Cathodal Current ◽  
Palmar Sweating

Passing galvanic current across the skin (known as "tap water iontophoresis" or TWI) inhibits sweating; however, its mechanism of action is unclear. Using improved methods, we confirmed that anodal current has more of an inhibitory effect than cathodal current, water is superior to saline, and the inhibitory effect is a function of the amperage used. To address the importance of current flowing through the pores, a layer of silicone grease was placed on the skin to reduce the shunt pathway across the epidermis. With silicone, total skin conductance decreased 60% without the sweat pores being occluded, swelling of the stratum corneum and collapse of the poral lumen was prevented, and current-induced inhibition of sweating was enhanced, most likely because of an increase in current density in the pores. The pH of anodal water, but not of saline, dropped to 3, whereas that of cathodal water increased to 10 during passage of current through the skin. Acidified anodal water was superior to alkaline water. Sweat glands isolated from TWI-induced anhidrotic palmar skin responded to methacholine in vitro, but the sweat rate and pharmacological sensitivity were slightly lowered. Thus the strong acidity generated by hydrolysis of water in the anodal bath and the further accumulation of H+ in the sweat duct by anodal current may be responsible for TWI-induced inhibition of sweating due to an unknown lesion(s) in the duct or sweat pore. The secretory coil function may also be altered because of exposure to intense acidity during TWI. The importance of H+ movement into the sweat pore for inhibition of sweating could be further exploited to develop new strategies for the control of sweating.

Excitatory synaptic actions between pairs of neighboring pyramidal tract cells in the motor cortex

1988 ◽  
Vol 59 (2) ◽  
pp. 636-647 ◽  
Author(s):  
Y. Kang ◽  
K. Endo ◽  
T. Araki
Keyword(s):  
Motor Cortex ◽  
Spontaneous Activity ◽  
Current Pulse ◽  
Pyramidal Tract ◽  
Surface Membrane ◽  
Extracellular Recording ◽  
Recording Electrode ◽  
Axon Collaterals ◽  
Pt Cell ◽  
Cathodal Current

1. By spike-triggered averaging, we documented recurrent individual excitatory postsynaptic potentials (EPSPs) produced in 33 pyramidal tract (PT) cells (target) by the activity of axon collaterals of neighboring single PT cells (reference) in the motor cortex of the cat. 2. The computer was triggered by the spontaneous activity of reference PT cells or by current pulses applied to reference PT cells through the extracellular recording electrode. 3. The threshold for direct activation of PT cells was less than 0.1 microA with an anodal current pulse and 0.2-0.3 microA with a cathodal current pulse. 4. Application of an anodal current pulse directly activated only a single reference PT cell, the surface membrane of which was presumably touched by and sucked with the extracellular recording electrode. 5. When a cathodal current pulse was used, simultaneous activation of neurons or axons other than the reference PT cell was checked by changing the stimulus parameters along the characteristic strength-duration curve for the reference PT cell and/or by comparing averaged EPSPs obtained by cathodal stimulation with those obtained from spontaneous spikes of the reference PT cell. 6. Recurrent individual EPSPs were produced in fast PT cells by activation of neighboring slow PT cells and also of neighboring fast PT cells. Some recurrent individual EPSPs were also observed in slow PT cells. 7. The mean latencies of recurrent individual EPSPs produced by the spontaneous activity of reference slow and fast PT cells were 1.61 (n = 12) and 1.12 ms (n = 8), respectively. Their amplitudes ranged between 30 and 390 microV (n = 33). The rise time observed in fast PT cells with activation of slow and fast PT cells ranged from 1.6 to 3.6 ms (n = 20) and from 0.8 to 1.9 ms (n = 10), respectively. 8. The average conduction velocity of axon collaterals of slow and fast PT cells was estimated to be as slow as that of unmyelinated fibers in the cat. 9. It is suggested that axon collaterals of slow PT cells synapse onto more distal dendrites of fast PT cells than axon collaterals of fast PT cells.

Mechanism of inhibitory effect of cathodal current tongue stimulation on five basic tastes

2016 ◽  
Author(s):  
Satoru Sakurai ◽  
Kazuma Aoyama ◽  
Nobuhisa Miyamoto ◽  
Makoto Mizukami ◽  
Masahiro Furukawa ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Cathodal Current

Evaluation of Passive and Iontophoretic Transport of Lisinopril from Hydrogel Matrix Across Model Membrane In Vitro

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Faruk A ◽  
Ishar P.S.
Keyword(s):  
Current Density ◽  
Drug Concentration ◽  
Drug Effect ◽  
Passive Diffusion ◽  
Rat Skin ◽  
Hydrogel Matrix ◽  
Drug Flux ◽  
Current Densities ◽  
Cathodal Current

Clinical studies of lisinopril delivery through iontophoresis are highly desired for better controls over transdermal drug flux. Therefore, investigations were carried out to ascertain the relative importance of the various factor for iontophoretic transport using an ionizable drug lisinopril, which has four pKa values 2.4, 4.0 (for amino group) and 6.7, 7.0 (for carboxylic group). Ionization of lisinopril varies with pH, hence rate and extent of transport across the skin can be enhanced, controlled and manipulated by the application of factors like anodal and cathodal current at varied pH of donor solution and current densities. To determine these parameters, experiments were performed and data were collected at 3.0, 4.0 and 7.4 pH using 4 mg/ml drug concentration and 0.1 mA/cm2 current density for 10 hours. After establishing the pH for optimum transport of drug, effect of current density (0.1, 0.2, 0.3 and 0.4 mA/cm2) on the transport of drug (keeping drug concentration constant) were investigated. Passive diffusion of lisinopril was maximal at pH 3.0, when unionized form of drug was 45%. Anodal iontophoresis was most effective (significant result, p less than 0.05) in transport of drug across skin as compared to cathodal iontophoresis at pH 3.0. While at pH 4.0, cathodal iontophoretic transport of lisinopril across rat skin was highly effective (Student‘t’ test, p less than 0.05) compared to anodal iontophoresis. The effect of current density on steady state flux of lisinopril during cathodal iontophoresis at 7.4 pH was 1.33 ± 1.12 and 24.8 ± 3.1 μg/cm2/h at 0.0 under passive diffusion and 4 mA/cm2, respectively. Thus, flux was enhanced nearly 18.6 times during anodal iontophoresis as compared to passive diffusion. For cathodal flux at pH 3.0 on similar iontophoretic treatment showed enhancement nearly 4 times.

The Repetitive Responses of Isolated Axons from the Crab, Carcinus Maenas

1966 ◽  
Vol 45 (3) ◽  
pp. 475-488
Author(s):  
R. A. CHAPMAN
Keyword(s):  
Refractory Period ◽  
Carcinus Maenas ◽  
Membrane Resistance ◽  
Physiological Solution ◽  
Response Frequency ◽  
Electrical Currents ◽  
Slowing Down ◽  
Relative Refractory Period ◽  
Repolarization Phase ◽  
Cathodal Current

1. A method is described that enables the electrical responses of motor axons isolated from the leg nerve of the crab Carcinus to be studied close to or at the site of imposed electrical currents, while this area is continuously bathed by physiological solution. 2. The three classes of repetitive responses originally described by Hodgkin (1948) have occurred during the present work and additional features of these responses have been described. 3. The results support Hodgkin's original thesis that the development of the spike generating mechanisms determine the response frequency during a repetitive response, but a progressive lengthening of the relative refractory period occurs during this response and is considered to be the agency that causes the gradual slowing down of the response frequency, i.e. the adaption. 4. The processes of membrane restoration (repolarization and recovery) have been shown to be sensitive to applied currents; anodal current hastening and cathodal current slowing it. These phenomena provide a basis for interpreting the change in the duration of the relative refractory period observed during the repetitive response. 5. The differences between the form of the repetitive response in the crab axon and the predictions of the Hodgkin-Huxley equations is discussed and it seems likely that the rapid recovery of the membrane resistance during the repolarization phase of the crab axon action potential underlies this difference.

Stabilization and rectification of muscle fiber membrane by tetrodotoxin

1960 ◽  
Vol 198 (5) ◽  
pp. 934-938 ◽  
Author(s):  
Toshio Narahashi ◽  
Takehiko Deguchi ◽  
Norimoto Urakawa ◽  
Yoshio Ohkubo
Keyword(s):  
Muscle Fiber ◽  
Muscle Fibers ◽  
Membrane Resistance ◽  
Frog Muscle ◽  
Resting Potential ◽  
Fiber Membrane ◽  
Delayed Rectification ◽  
Intracellular Microelectrodes ◽  
Cathodal Current ◽  
Muscle Fiber Membrane

The mode of action of tetrodotoxin on the frog muscle fiber membrane has been analyzed with the aid of intracellular microelectrodes. Tetrodotoxin of 10–7 concentration made the applied cathodal current ineffective in producing action potential, whereas the resting potential and resting membrane resistance underwent little or no change. With 10–8 tetrodotoxin the muscle fibers responded with the small action potentials at high critical depolarizations. These results can be explained on the basis of the membrane being stabilized by inactivation of the sodium-carrying mechanism. Although delayed rectification was not observed in normal muscle fibers, it became apparent in the fibers rendered inexcitable by tetrodotoxin. This finding, together with other evidence in the existing literature, supports an applicability of the sodium theory to the frog muscle fibers.

Relationship of current parameters to hyperpnea produced by brain polarization

1965 ◽  
Vol 209 (6) ◽  
pp. 1247-1253
Author(s):  
Richard O. Davies ◽  
William S. Yamamoto
Keyword(s):  
Brain Stem ◽  
Rat Brain ◽  
Ventilatory Response ◽  
Negative Bias ◽  
Stimulus Parameters ◽  
Cathodal Current ◽  
Relationship Of ◽  
Sinusoidal Currents

The phenomenon of synchronized hyperpnea, produced by applying biased sinusoidal currents to a circumscribed area of the rat brain stem, was characterized in terms of some stimulus parameters. Ventilation was increased when the amplitude of the sinusoidal component was increased; at 1 cycle/sec and negative bias, V = 851 + 123. The magnitude of the hyperpnea was frequently dependent. Of the frequencies tested (0, 1, 2, 3, and 4 cycles/sec), a stimulus of 2 cycles/sec elicited the largest ventilatory response. In the absence of a sinusoidal component, the effect of cathodal current on ventilation was given by the equation V = .421 + 134. As an anode, the electrode exerted no significant effect on ventilation.

scholarly journals DUAL-tDCS Treatment over the Temporo-Parietal Cortex Enhances Writing Skills: First Evidence from Chronic Post-Stroke Aphasia

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 343
Author(s):  
Francesca Pisano ◽  
Carlo Caltagirone ◽  
Chiara Incoccia ◽  
Paola Marangolo
Keyword(s):  
Parietal Cortex ◽  
Critical Role ◽  
Writing Skills ◽  
Double Blind ◽  
Post Stroke ◽  
Lexical Route ◽  
Left And Right ◽  
Cathodal Current ◽  
First Time

The learning of writing skills involves the re-engagement of previously established independent procedures. Indeed, the writing deficit an adult may acquire after left hemispheric brain injury is caused by either an impairment to the lexical route, which processes words as a whole, to the sublexical procedure based on phoneme-to-grapheme conversion rules, or to both procedures. To date, several approaches have been proposed for writing disorders, among which, interventions aimed at restoring the sub-lexical procedure were successful in cases of severe agraphia. In a randomized double-blind crossover design, fourteen chronic Italian post-stroke aphasics underwent dual transcranial direct current stimulation (tDCS) (20 min, 2 mA) with anodal and cathodal current simultaneously placed over the left and right temporo-parietal cortex, respectively. Two different conditions were considered: (1) real, and (2) sham, while performing a writing task. Each experimental condition was performed for ten workdays over two weeks. After real stimulation, a greater amelioration in writing with respect to the sham was found. Relevantly, these effects generalized to different language tasks not directly treated. This evidence suggests, for the first time, that dual tDCS associated with training is efficacious for severe agraphia. Our results confirm the critical role of the temporo-parietal cortex in writing skills.

Transtympanic Electrically Evoked Auditory Sensations

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 92-93 ◽  
Author(s):  
W. P. R. Gibson ◽  
C. J. A. Game ◽  
C. K. Pauka
Keyword(s):  
Electric Current ◽  
Round Window ◽  
Cathodal Current ◽  
Nerve Excitation

A transtympanic needle was used to inject electric current near the round window niches of totally deaf ears. Bursts of 50- or 100-Hz square waves evoked hearing from most of the tested ears. Various stimulus waveforms were used to show the usual phenomena of nerve excitation (eg, anode break excitation, anodal current inhibition, and cathodal current excitation).

Electrical and anatomic characteristics of cells of ferret paratracheal ganglion

1984 ◽  
Vol 246 (5) ◽  
pp. C450-C458 ◽  
Author(s):  
A. R. Cameron ◽  
R. F. Coburn
Keyword(s):  
Electrical Stimulation ◽  
Cell Types ◽  
Excitatory Postsynaptic Potential ◽  
Similar Response ◽  
Single Action ◽  
Postsynaptic Potential ◽  
Cathodal Current ◽  
Stimulation Of Nerve ◽  
Electron Lucent ◽  
Stimulation Of

A preparation has been developed for study of the electrical properties of the neurons of the ferret paratracheal ganglia. Two cell types were identified. AH cells were characterized by the presence of a single action potential in response to cathodal current pulses, followed by a profound after hyperpolarization that lasted for several hundred milliseconds. Electrical stimulation of branches of the laryngeal nerves produced a fast excitatory postsynaptic potential (EPSP) that was often followed by an apparent inhibitory postsynaptic potential (IPSP). A similar response was seen with electrical stimulation of interganglionic nerve trunks. Hexamethonium reversibly inhibited fast EPSPs in these cells. Type B cells could not be excited by intracellular current injections. At least some of these cells appear to be neurons as electrical stimulation of nerve trunks resulted in a slow EPSP and, rarely, a fast IPSP. Ganglia have between 10 and 20 cell bodies, and their diameters are between 15 and 40 microns. Two types of nerve endings were seen: 1) those with mainly round agranular vesicles 50–60 nm in diameter, and 2) those with large dense-cored vesicles of approximately 100 nm with an electron-lucent halo around the core.

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