scholarly journals The Response of the Ampullae of Lorenzini of Elasmobranchs to Electrical Stimulation

1962 ◽  
Vol 39 (1) ◽  
pp. 119-128 ◽  
Author(s):  
R. W. MURRAY
Keyword(s):  
Electrical Stimulation ◽  
Sense Organ ◽  
Voltage Gradient ◽  
Water Interface ◽  
After Effects ◽  
Ampullae Of Lorenzini ◽  
Electrical Stimuli ◽  
A Current

1. The ampullae of Lorenzini are sensitive to weak electrical stimuli which presumably cause currents to flow along the jelly-filled tubes of the sense organ. Increase of the resting frequency occurs when the tube-opening is made negative to the capsule, and inhibition when the opening is positive, with opposite after-effects in each case. Adaptation is three-quarters complete in about 5 sec. 2. When the stimulus is applied as a voltage gradient in the water overlying the ampullae, the threshold for the most sensitive units is 1 µV./cm., which represents a current along the tube of less than 5 x 10-11 A. 3. When the stimulus is applied as a current directly to the tube opening, the threshold for the most sensitive units is 4 x 10-10 A. 4. Changes in the salinity of the water at the tube opening are also effective, the threshold being about 3%. Dilution causes excitation, and concentration causes inhibition. The response is not due to the osmotic differences, and so probably results from potentials established at the jelly-water interface.

scholarly journals V. On the "blaze currents" of the frog's eyeball

1901 ◽  
Vol 194 (194-206) ◽  
pp. 183-233 ◽  
Keyword(s):  
Electrical Stimulation ◽  
Positive Response ◽  
Electrical Response ◽  
Electrical Current ◽  
Positive Direction ◽  
Electrical Stimuli ◽  
Counter Current ◽  
A Current

In a recent communication to the Society I have stated that the normal electrical response of the eye to light consists in a current traversing the eye ball in a positive direction, i. e . from fundus to cornea, and that a similar positive response is aroused by meachanical and by electrical stimuli, whatever be the direction of the latter. I have designated this positive response to non-luminous stimuli as the retainal discharge or blaze. With reference to electrical stimulation, its most characteristic from is when it occurs in the same dorection as the current by which it is excited, i. e . when it cannot be polarisation counter-current. It is in such case analogous with the discharge of an electrical organ excited by an electrical current in the direction of normal discharge, and, indeed, it may be of such magnitued as to lead an observer to regard retain in the light of an electrical organ.

scholarly journals Interpretation of the Repetitive Firing of Nerve Cells

1962 ◽  
Vol 45 (6) ◽  
pp. 1163-1179 ◽  
Author(s):  
M. G. F. Fuortes ◽  
Francoise Mantegazzini
Keyword(s):  
Nerve Cells ◽  
Principal Factor ◽  
Current Intensity ◽  
Moderate Intensity ◽  
Repetitive Firing ◽  
Important Process ◽  
Current Step ◽  
After Effects ◽  
Graded Activity ◽  
A Current

Eccentric cells of Limulus respond with repetitive firing to sustained depolarizing currents. Following stimulation with a step of current, latency is shorter than first interval and later intervals increase progressively. A shock of intensity twice threshold can evoke firing 25 msec. after an impulse. But in the same cell, a current step twice rheobase evokes a second impulse more than 50 msec. after the first, and current intensity must be raised to over five times rheobase to obtain a first interval of about 25 msec. Repetitive firing was evoked by means of trains of shocks. With stimuli of moderate intensity, firing was evoked by only some of the shocks and intervals between successive impulses increased with time. This is ascribed to accumulation of refractoriness with successive impulses. Higher frequencies of firing are obtained with shocks of intensity n x threshold than with constant currents of intensity n x rheobase. It is concluded that prolonged currents depress the processes leading to excitation and that (in the cells studied) repetitive firing is controlled both by the after-effects of firing (refractoriness) and by the depressant effects of sustained stimuli (accommodation). Development of subthreshold "graded activity" is an important process leading to excitation of eccentric cells, but is not the principal factor determining frequency of firing in response to constant currents.

Attempts to Suppress Tinnitus with Transcutaneous Electrical Stimulation

1985 ◽  
Vol 93 (3) ◽  
pp. 385-389 ◽  
Author(s):  
Jack A. Vernon ◽  
James A. Fenwick
Keyword(s):  
Electrical Stimulation ◽  
Positive Response ◽  
Transcutaneous Electrical Stimulation ◽  
Therapeutic Procedure ◽  
Placebo Trial ◽  
Electrical Stimuli ◽  
Severe Tinnitus

Various electrical stimuli were tested for their ability to suppress or relieve severe tinnitus. Stimulation was applied transdermally by electrodes placed on the preauricular and postauricular regions and on the two mastoids. Of the 50 patients tested, only 14 (28%) obtained relief that met the criterion of a reduction in the tinnitus by 40% or more. When relief was obtained, it usually extended for several hours into the poststimulation period. There was only one positive response (2%) In the placebo trial, which was administered to all patients. It was concluded that transdermal electrical stimulation such as that used in this research Is not a practical therapeutic procedure for the relief of tinnitus.

scholarly journals II. Post-Tetanic Potentiation and Depression of Generator Potential in a Single Non-Myelinated Nerve Ending

1959 ◽  
Vol 43 (2) ◽  
pp. 347-376 ◽  
Author(s):  
Werner R. Loewenstein ◽  
Stanley Cohen
Keyword(s):  
Mechanical Stimulation ◽  
Sense Organ ◽  
Critical Parameters ◽  
Resting Membrane Potential ◽  
Ranvier Node ◽  
Generator Potential ◽  
After Effects ◽  
Receptor Membrane ◽  
Post Tetanic Potentiation ◽  
Stimulation Of

Repetitive activity at the non-myelinated ending of Pacinian corpuscles leaves the following after-effects: (1) With certain parameters of repetitive mechanical stimulation of the ending a depression in generator potential is produced. The effect is fully reversible and has low energy requirements. The effect is a transient decrease in responsiveness of the receptor membrane which is unrelated to changes in resting membrane potential. It appears to reflect an inactivation process of the receptor membrane. Within certain limits, the depression increases as a function of strength, frequency, and train duration of repetitive stimuli. (2) With other, more critical parameters of repetitive stimulation a hyperpolarization of the ending and of the first intracorpuscular Ranvier node may be produced. This leads to respectively post-tetanic potentiation of generator potential and increase in nodal firing threshold. The balance of these after-effects determines the threshold for the production of nerve impulses by adequate (mechanical) stimulation of the sense organ. The after-effects of activity at the node can be elicited by dromic (mechanical) stimulation of the ending, as well as by antidromic (electric) stimulation of the axon; the after-effects at the ending can only be produced by dromic and not by antidromic stimulation.

scholarly journals Evaluation of PC12 Cell Neural Differentiation on Graphene Coated ITO Microchips

2020 ◽  
Author(s):  
Tansu Golcez ◽  
Fikri seven ◽  
Ozan Karaman ◽  
Mustafa Sen
Keyword(s):  
Electrical Stimulation ◽  
Neuronal Differentiation ◽  
Indium Tin Oxide ◽  
Neural Differentiation ◽  
Neuronal Cell ◽  
Large Degree ◽  
Neuronal Cell Differentiation ◽  
Electrical Stimuli ◽  
The Impact ◽  
Real Time Qpcr

In this study, the impact of graphene on neuronal differentiation of PC12 cells into neuron-like cells was evaluated in conjunction with electrical stimuli. First, an ITO (Indium Tin Oxide) microchip with a certain number of electrodes was fabricated using photolithography and then a chemically synthesized graphene was coated on the microchip. The electrical stimulation was applied through the ITO-microchip. Following optimization of neuronal differentiation conditions, the effect of AC and DC electrical stimulation on both bare and graphene-coated ITO-microchips for neuronal differentiation was investigated. According to the results, it was observed that electrical stimulation with direct current for 30 minutes caused a large degree of neuronal cell differentiation on the graphene coated ITO-microchips. The results were also verified by real-time qPCR.

Determination of the Dipole Moment of a Monolayer at the Air/Water Interface Using a Current-Measuring Technique

1988 ◽  
Vol 27 (Part 1, No. 5) ◽  
pp. 721-725 ◽  
Author(s):  
Mitsumasa Iwamoto ◽  
Yutaka Majima
Keyword(s):  
Dipole Moment ◽  
Measuring Technique ◽  
Water Interface ◽  
Air Water Interface ◽  
Current Measuring ◽  
A Current

Innervation of cat iris dilator

1964 ◽  
Vol 207 (6) ◽  
pp. 1411-1416 ◽  
Author(s):  
U. Schaeppi ◽  
W. P. Koella
Keyword(s):  
Electrical Stimulation ◽  
Adrenergic Receptors ◽  
Isometric Tension ◽  
Adrenergic Nerve ◽  
Nerve Terminals ◽  
Beta Adrenergic Receptors ◽  
Dilator Muscle ◽  
Adrenergic Nerve Terminals ◽  
Electrical Stimuli

Isometric tension changes of radially oriented iris strips of the cat were investigated in vitro. Electrical stimulation, norepinephrine (NE), and tyramine elicited contraction whereas isoproterenol elicited relaxation. Phentolamine reduced electrically and NE induced contractions and, in large doses, converted them to relaxation. Dichloroisoproterenol decreased this relaxation and the relaxation induced by isoproterenol. After chronic sympathetic denervation, electrical stimuli induced mainly relaxation and tyramine had no effect. These results indicate that contractions and relaxations in normal preparations are preponderantly mediated via excitation of adrenergic nerve terminals and release of adrenergic transmitter acting upon alpha and beta adrenergic receptors, respectively. Neostigmine and atropine had little effect on the electrically induced effects of normal preparations. In chronically denervated dilator strips, neostigmine increased and atropine decreased the relaxations and occasional slight contractions produced by electrical stimuli. These observations are interpreted that cholinergic relaxation mechanisms are also involved in the control of the dilator muscle, and that cholinergic contractions are due to activation of aberrant sphincter fibers contaminating the dilator muscle.

Effect of Increased Sodium ION on Arterial Sodium and Reactivity

1972 ◽  
Vol 42 (3) ◽  
pp. 301-309 ◽  
Author(s):  
G. S. Harris ◽  
W. A. Palmer
Keyword(s):  
Electrical Stimulation ◽  
Arterial Wall ◽  
Sodium Concentration ◽  
Sodium Content ◽  
Sodium Ion ◽  
Rabbit Ear ◽  
Arterial Reactivity ◽  
Electrical Stimuli ◽  
Constrictor Response ◽  
Environmental Fluid

1. Isolated rabbit arterial segments were perfused with buffer containing sodium (155 mmol/l) and vasoconstrictor responses to noradrenaline, histamine and electrical stimulation were measured. When the concentration of sodium in the perfusing medium was raised by 8 mmol/l, the vasoconstrictor responses to all stimuli were significantly increased, though response to electrical stimulation was less enhanced than the responses to the other stimuli. 2. The constrictor response of the isolated perfused rabbit ear to angiotensin was also enhanced by perfusion with buffer of a similarly enriched sodium content. 3. Ileal responses to electrical stimulation and atrial responses to electrical stimuli and noradrenaline were also examined after exposure to similar changes of environmental sodium. No change in responsiveness was demonstrated. 4. Isotope-exchange studies with 22Na showed that this small increase in sodium concentration of the environmental fluid caused an increased sodium ion content of 20% in arterial wall, 5% in ileum and 11% in atrium. 5. It is suggested that a relationship exists between increased exchangeable sodium ion in arterial wall and arterial reactivity.

scholarly journals Remote Control of the Swimmeret Central Pattern Generator in Crayfish (Procambarus Clarkii and Pacifastacus Leniusculus): Effect of a Walking Leg Proprioceptor

1992 ◽  
Vol 169 (1) ◽  
pp. 181-206 ◽  
Author(s):  
DANIEL CATTAERT ◽  
JEAN-YVES BARTHE ◽  
DOUGLAS M. NEIL ◽  
FRANCOIS CLARAC
Keyword(s):  
Electrical Stimulation ◽  
Mechanical Stimulation ◽  
Procambarus Clarkii ◽  
Beat Frequency ◽  
Rhythmic Activity ◽  
Chordotonal Organ ◽  
Disruptive Effect ◽  
Mechanical Stimuli ◽  
Electrical Stimuli ◽  
Stimulation Of

1. An isolated preparation of the crayfish nervous system, comprising both the thoracic and the abdominal ganglia together with their nerve roots, has been used to study the influence of a single leg proprioceptor, the coxo-basal chordotonal organ (CBCO), on the fictive swimmeret beating consistently expressed in this preparation. Both mechanical stimulation of the CBCO and electrical stimulation of its nerve were used. 2. In preparations not displaying rhythmic activity, electrical or mechanical stimulations evoked excitatory postsynaptic potentials (EPSPs) in about 30 % of the studied motor neurones with a fairly short and regular delay, suggesting an oligosynaptic pathway. Such stimulation could evoke rhythmic activity in swimmeret motor nerves. The evoked swimmeret rhythm often continued for several seconds after the stimulus period. 3. When the swimmeret rhythm was well established, electrical and mechanical stimuli modified it in a number of ways. Limited mechanical or weak electrical stimuli produced a small increase in swimmeret beat frequency, while more extreme movements of the CBCO or strong electrical stimuli had a disruptive effect on the rhythm. 4. The effect of low-intensity stimulation on existing swimmeret beating was phase-dependent: it shortened the beat cycle when applied during the powerstroke phase and lengthened it when applied during the retumstroke phase. 5. Rhythmic mechanical stimulation of CBCO or electrical stimulation of the CBCO nerve entrained the swimmeret rhythm within a limited range in relative or absolute coordination. Note: To whom reprint requests should be sent.

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