Simulation Studies of Ultrashort, High-Intensity Electric Pulse Induced Action Potential Block in Whole-Animal Nerves

2008 ◽  
Vol 55 (4) ◽  
pp. 1391-1398 ◽  
Author(s):  
R.P. Joshi ◽  
A. Mishra ◽  
Jiahui Song ◽  
A.G. Pakhomov ◽  
K.H. Schoenbach
Keyword(s):  
Action Potential ◽  
High Intensity ◽  
Electric Pulse ◽  
Simulation Studies

scholarly journals Effect of pulsed high intensity focused ultrasound on the nerve compound action potential amplitude and conduction velocity

2021 ◽  
Author(s):  
Steve Tran
Keyword(s):  
Action Potential ◽  
Conduction Velocity ◽  
High Intensity ◽  
Focused Ultrasound ◽  
Compound Action Potential ◽  
Homarus Americanus ◽  
High Intensity Focused Ultrasound ◽  
Nerve Tissue ◽  
Nerve Function ◽  
Compound Action

Therapeutic HIFU has been used as a non-invasive energy modality to compromise nerve function since the 1950s. Several contributions have been made in recent years to characterize these effects on nerve function. In this study, short repeated bursts of HIFU, termed as pulsed high intensity focused ultrasound (pHIFU), was directed at nerve tissue. The pHIFU transducer operated at a central frequency of 1.95 MHz and had a focal length of approximately 12 cm. The ventral nerve cord from the American Lobster (Homarus americanus), n=15, was sonicated cumulatively at 3 exposure times: 1s, 6s, and 16s, at an intensity of 1010 W/cm2, or focal pressure of 5.51 MPa. The compound action potential (CAP) and conduction velocity (CV) were seen to decrease as sonication exposure time to the nerve increased. The experiments performed demonstrate the feasibility to modulate nerve CAP and nerve CV using non-thermal mechanisms of ultrasound.

Effect of High-Intensity X-Radiation on the A Group Fibers of the Frog's Sciatic Nerve

1956 ◽  
Vol 184 (2) ◽  
pp. 333-337 ◽  
Author(s):  
Herbert B. Gerstner
Keyword(s):  
Sciatic Nerve ◽  
Ionizing Radiation ◽  
Action Potential ◽  
Rise Time ◽  
High Intensity ◽  
Dose Range ◽  
Monophasic Action Potential ◽  
Potential Amplitude ◽  
Complete Failure ◽  
Sciatic Nerves

Isolated sciatic nerves of bullfrogs received x-radiation at a dose rate of 9 kr/min. Prior to and following exposure, the monophasic action potential was recorded. In alpha fibers, doses between 75 kr and 200 kr caused a decrease in conduction velocity, an increase in the rise time of the action potential, and an elevated rheobase with shortened chronaxie; the potential amplitude was not obviously affected. In the dose range above 200 kr, the potential amplitude declined rapidly and complete failure of function occurred at about 300 kr. Beta fibers closely resembled alpha fibers in behavior; however, they appeared to be somewhat more radioresistant than a portion of the alpha subdivision. Gamma fibers seemed to be most susceptible to ionizing radiation; their potential disappeared at doses between 150 kr and 200 kr.

A model analysis of aftereffects of high-intensity DC stimulation on action potential of ventricular muscle

1998 ◽  
Vol 45 (2) ◽  
pp. 258-267 ◽  
Author(s):  
I. Sakuma ◽  
T. Haraguchi ◽  
K. Ohuchi ◽  
Y. Fukui ◽  
I. Kodama ◽  
...  
Keyword(s):  
Action Potential ◽  
High Intensity ◽  
Model Analysis ◽  
Ventricular Muscle

The Motivational Organisation Controlling the Mobbing Calls of the Blackbird (Turd Us Merula). Ii. the Quantitative Analysis of Changes in the Motivation of Calling

Behaviour ◽  
1961 ◽  
Vol 17 (4) ◽  
pp. 288-321 ◽  
Author(s):  
R.J. Andrew
Keyword(s):  
Quantitative Analysis ◽  
Action Potential ◽  
High Intensity ◽  
Neural System ◽  
Minimum Period ◽  
Physical Limit ◽  
Adequate Analysis ◽  
Rate Of Accumulation

Abstract1. At least two variables must be used for the adequate analysis of the changes observed in calling. The first has been here termed Action Potential (A). When the value of A at calling is above a certain threshold 'tix' is given instead of 'duck'. A is caused to rise both by activity of the neural system controlling flight and by the sight of a frightening object. It is reduced by calling, probably at or just after each call. 2. A second variable, the General Threshold for calling (T), must also be employed to explain the data obtained. When A is below T no calls can occur. T is increased by calling (probably at each call, since there is some evidence that it decays between calls). It therefore rises progressively during bouts. As a result the interval between the last two calls of a bout is an unusually long one, and the change to 'tix' is irreversible within a bout. Between bouts T decays, so that the longer the pause between bouts the shorter the intervals between calls at the beginning of the next bout, and the less likely is it that the first call will be 'tix'. 3. The higher the value of T at the beginning of a bout the longer the intervals between calls and the more likely is the change to 'tix', since A has to rise to equal T before calling can occur. 4. T tends to fall a take-off and rise at landing. 5. High intensity calling may take two forms which are caused by differences in the rate of accumulation of T. When T accumulates slowly the intervals between calls readily decrease until the physical limit is reached, and a scream results, in the course of which the change to a 'tix' type of calling occurs. A scream is initiated only after the activity of flight has continued for more than a minimum period of time, which is longer the lower the intensity of mobbing. When T accumulates readily, long bouts result, which are entirely composed of 'tix' calls, given at unusually long intervals.

scholarly journals Effect of high intensity focused ultrasound on neural compound action potential : an in vitro study

2021 ◽  
Author(s):  
Shahrad Jabbary.
Keyword(s):  
Action Potential ◽  
High Intensity ◽  
Focused Ultrasound ◽  
Compound Action Potential ◽  
The Body ◽  
High Intensity Focused Ultrasound ◽  
Acoustic Energy ◽  
Focal Intensity ◽  
Compound Action

Therapeutic ultrasound is a promising field with many novel applications in medicine and biology. High intensity focused ultrasound (HIFU) provides the ability to localize the deposition of acoustic energy within the body by thermal effect. In this work a brief description of how the HIFU system works and how it can be used to produce localized thermal lesions on the pathogenic tissues in the human body will be presented. Results of acoustic characterization of a hand-held HIFU system developed in our lab will also be presented. The capabilities of creating controlled reversible and irreversible changes in the compound action potential (CAP) values of a specific neural tissue, i.e. lobster abdominal nerves by adjusting different ultrasound parameters (intensity, exposure duration, etc.) in the HIFU system will also be described. Lobster abdominal nerves were exposed to a 10s HIFU exposure. The focal intensity values for this study were chosen as 100, 175, 275, 400, 525 and 700 W .cm ⁻². It was shown that a trend of small changes in the measured CAP values (increase in the CAP amplitude) could be achieved in the five intermediate intensities, while a drastic decrease in the measured CAP values and total degeneration of the nerve could be observed with the highest focal intensity of 700 W .cm⁻².

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