2.2 Holographic Study of Structural and Functional Characteristics …
103
could observe plus phase amplitude incidence of electromyographic response and
its negative component increasing trend.
The mentioned-above publication review allows concluding that the influence of
magnetic fields reveals as a weak effect, for the recording of which highly sensitive
methods and often long time of observation are needed.
2.2.6 Study of the Influence of Powerful Pulsed Magnetic
Field on the State of Isolated Nerve
The study of the influence of powerful pulsed magnetic field [323] on the state of
the isolated nerve was carried out in the work [14]. Isolated sciatic nerves of brown
frog Rana temporaria were the object of electrophysiological inquiry of the influence
of powerful pulsed magnetic field. The nerve trunk with an average length of 5 cm
was prepared by a common method and placed in Ringer’s solution for cold-blooded
animals for 1–2 h for demarcation potential decrease. Then, the preparation was
transported to specially made moist chamber for electrophysiological studies.
The nerve was stimulated by electric current rectangular pulse with the voltage of
5–10 V and time of 50 μs. Action potential (AP) was recorded using a hanging silver
electrode at a distance of 5 mm between them. During the experiment, the chamber
was shut tight with the cover with an optically transparent area that during the work
allows controlling the conditions of bioelectrical signals retractions and avoiding the
preparation drying up. AP was being recorded over a long period of time (up to 48
h).
Experimental setup consisted of an electrostimulator of EW-2 type, a bioelectricpotential amplifier with the bandwidth from 10 Hz to 20 kHz and 10 megaohm input
resistance, an oscilloscope and a digital time-domain voltmeter of V4-17-type.
To achieve the goals of the present part of the work, we measured maximum
amplitude of the nerve action potential before, directly after and in some time after
the influence of magnetic field. AP amplitude has been chosen as the criterion of
preparation functional state as it is the integral index of nerve cells participation,
which forms nerve trunk, in the conduction of excitement. Moreover, AP amplitude
is a stably registrable index, which can be objectively detected by pulsed voltmeter.
The measurement mode was based on the fact that the pulsed magnetic field
causes strong framings in electronic circuits, which distort and reject desired
signal and, in some cases, disable highly sensitive electromeasuring apparatus.
At the moment of pulse magnet influence, the chamber with the preparation was
switched off the stimulator and amplifier. Besides it excluded the nerve stimulation by pulsed electric framing on the cyclic conductor–electrode–wire–device input
resistance–wire–electrode–nerve.
During the experiment, electric current pulses of increasing amplitude caused peak
response of the nerve. Then, stimulus amplitude was decreased until AP appeared,
the value of which was half-peaked. By this, some part of nerve fibers in the trunk
103
could observe plus phase amplitude incidence of electromyographic response and
its negative component increasing trend.
The mentioned-above publication review allows concluding that the influence of
magnetic fields reveals as a weak effect, for the recording of which highly sensitive
methods and often long time of observation are needed.
2.2.6 Study of the Influence of Powerful Pulsed Magnetic
Field on the State of Isolated Nerve
The study of the influence of powerful pulsed magnetic field [323] on the state of
the isolated nerve was carried out in the work [14]. Isolated sciatic nerves of brown
frog Rana temporaria were the object of electrophysiological inquiry of the influence
of powerful pulsed magnetic field. The nerve trunk with an average length of 5 cm
was prepared by a common method and placed in Ringer’s solution for cold-blooded
animals for 1–2 h for demarcation potential decrease. Then, the preparation was
transported to specially made moist chamber for electrophysiological studies.
The nerve was stimulated by electric current rectangular pulse with the voltage of
5–10 V and time of 50 μs. Action potential (AP) was recorded using a hanging silver
electrode at a distance of 5 mm between them. During the experiment, the chamber
was shut tight with the cover with an optically transparent area that during the work
allows controlling the conditions of bioelectrical signals retractions and avoiding the
preparation drying up. AP was being recorded over a long period of time (up to 48
h).
Experimental setup consisted of an electrostimulator of EW-2 type, a bioelectricpotential amplifier with the bandwidth from 10 Hz to 20 kHz and 10 megaohm input
resistance, an oscilloscope and a digital time-domain voltmeter of V4-17-type.
To achieve the goals of the present part of the work, we measured maximum
amplitude of the nerve action potential before, directly after and in some time after
the influence of magnetic field. AP amplitude has been chosen as the criterion of
preparation functional state as it is the integral index of nerve cells participation,
which forms nerve trunk, in the conduction of excitement. Moreover, AP amplitude
is a stably registrable index, which can be objectively detected by pulsed voltmeter.
The measurement mode was based on the fact that the pulsed magnetic field
causes strong framings in electronic circuits, which distort and reject desired
signal and, in some cases, disable highly sensitive electromeasuring apparatus.
At the moment of pulse magnet influence, the chamber with the preparation was
switched off the stimulator and amplifier. Besides it excluded the nerve stimulation by pulsed electric framing on the cyclic conductor–electrode–wire–device input
resistance–wire–electrode–nerve.
During the experiment, electric current pulses of increasing amplitude caused peak
response of the nerve. Then, stimulus amplitude was decreased until AP appeared,
the value of which was half-peaked. By this, some part of nerve fibers in the trunk