International Journal of Modern Nonlinear Theory and Application, 2013, 2, 7-13
http://dx.doi.org/10.4236/ijmnta.2013.21002 Published Online March 2013 (http://www.scirp.org/journal/ijmnta)
Classic and Non-Classic Soliton Like Structures for
Traveling Nerve Pulses
Fidel Contreras
1
, Hilda Cervantes
1
, Máximo Aguero
1
, Ma. de Lourdes Najera
2
1
Facultad de Ciencias, Universidad Autónoma del Estado de México,
Toluca de Lerdo, México
2
Plantel Nezahualcoyotl, Universidad Autónoma del Estado de México,
Toluca de Lerdo, México
Email: maaguerog@uaemex.mx
Received December 10, 2012; revised January 18, 2013; accepted January 28, 2013
ABSTRACT
After some reduction procedure made on the nonlinear evolution equation for nerve pulses, based on thermodynamic
principles, new classic and non-classic traveling solutions have been obtained. We have studied this model for par-
ticular values in the parameter space, and obtained both the bell and compacton like solutions. These nonlinear traveling
waves could be responsible for transmitting efficiently the necessary information along the axons. The non-classic
structures named as compactons, due to their robust configuration, could be considered in some sense a more realistic
type of nonlinear chargers of information. The last solutions do not have tails and as adiabatic waves could propagate
along the nerve with constant velocity that could be equal, smaller or higher than the sound velocity.
Keywords: Compactons; Nonlinear Waves; Solitons; Nerve Pulse; Molecular Waves
1. Introduction
One of key fundamental problems in biophysics is to
understand how nature makes to carry information with-
out significant distortion along distances between two
considerable long separated centers. Now it is well estab-
lished that the dynamic of ionic currents through voltage
channels is responsible for the change of the membrane
potential in nerve tissues. As is well known the first
measurements on ionic currents were performed by
Hodgkin and Huxley (HH) in the 50s [1]. In 1966 Katz
[2] proposed for traveling pulse the soliton traveling pul-
se as a simplest model for this activity.
Later, the Hodgkin and Huxley system was developed
independently by Richard FitzHugh, and Jin-ichi Na-
gumo [3,4]. Based on the work of Balthazar Van Der Pol,
FitzHugh proposed a simplified neuronal model of Hodg-
kin and Huxley. For its part, Nagumo suggested as ana-
logous neuronal, a nonlinear electrical circuit, controlled
by an equation system also similar to those of Van Der
Pol currents. The proposed simplified analog of these
authors, is called FitzHugh-Nagumo model. Being sus-
ceptible fairly complete analysis, the FHN system allows
a qualitative understanding of the phenomenon of excit-
ability, from the point of view of dynamic systems [5]
and constitutes a classical model of neurophysiology.
The current importance of this model is beyond the scope
of biophysics and neurophysiology, being of interest to
researchers who need to understand the wide range of
nonlinear phenomena accompanying the phenomenon of
excitability. By introducing an approximate scheme to
the famous model of Hodgkin-Huxley, Muratov in his
paper [6] obtained solitary wave pulse for nerve conduc-
tance and obtained the value of velocities that are in
agreement with experimental results.
Recently, Heimburg and coworkers have developed a
model for nerve pulses that support soliton like solutions
[7-10]. The model is constructed considering the nerve
axon as a one dimensional cylinder with lateral density
excitations moving along the axes that is represented by
the coordinate z. This model shows the appearance of
lipid phase transition slightly below physiological tem-
peratures. Given measured values of the compression
modulus as a function of lateral density and frequency,
soliton properties can be determined by the velocity of
the traveling waves. That is, resuming we can say that
this theory is based on the lipid transition from a fluid to
a gel phase at slightly below of body temperatures. The
effects of nonlinearity and dispersion as is common
would be responsible for appearance of soliton like struc-
tures in nerve membrane in the gel state [10] and more
recent results on soliton and periodical solutions can be
found in [11].
On the other hand, as is well known, classical solitons
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