8 A Self-Organized Rhythm in Peripheral Effectors: The Intermediary …
145
These variations itself represent an essential physiological property, namely adapting
to order various rhythms in a n:m integer number mode. Thus, the function of this
0.15 Hz rhythm band elicited coupling between cardiovascular and respiration time
series which was enhanced as amplitudes of the 0.15 Hz rhythm in reticular neurons
increased.[4, 18].
Analogies between canine and human were also found in amplitude dynamics.
Spindle wave shaped amplitude modulation epochs were prevalent in the recordings
of the reticular neurons as well as in human recordings of facial skin blood content
oscillations [4, 11–13, 18]. These analogous findings in canine and human lead us
to suggest that the 0.15 Hz rhythm band in facial skin microcirculation of humans
results from coherent oscillatory neuronal activity in the lower brain stem.
In the present communication, we are able to further our understanding of essential
rhythmic principles governing the cardiovascular-respiratory coordination in human.
We demonstrate the interaction between spindles shaped amplitude modulations
of the 0.15 Hz rhythm band and the cardiac attractor. There is an evident inverse
relationship between the power of the spindle and the power of the cardiac 1.2 Hz
frequency band. As spindles reach a maximum, the power of the 1.2 Hz frequency
band becomes distinctly weaker. When lacking amplitude modulations in the 0.15 Hz
rhythm band, the power of the cardiac attractor reaches a maximum. This suggests
closer considerations of the interplay of frequency and amplitude modulations. As for
the dynamics of the frequency dynamics exhibited by the 0.15 Hz rhythm band, we
have expanded our understanding labelling this rhythm since 0.15 Hz is the frequency
precisely between the frequencies of rhythms exhibited by the two branches of the
autonomic nervous system, the sympathetic and parasympathetic nervous system.
We ,therefore, chose to refer to this rhythm as the intermediary rhythm abandoning
a merely phenomenological term in favour of a term which outlines an important
physiological feature.
As this concept of the amplitude modulated „intermediary rhythm” is subjected
to closer scrutiny, it is important to start from the well-known fact that relay neurons
are surrounded by pools of small interneurons. As one further assumes that the latter
are predisposed to function as “inhibitors” (owing to their neurosecretory products,
namely glycine or γ-amino buturylic acid (GABA), it can be insinuated that by mechanisms of “collateral inhibition”, the supra-threshold excitation of any relay neuron
is associated with delayed inhibition due to circulating excitations within the pool of
small interneurons. Furthermore, in assuming that small neurons are easily excited
but poorly inhibited, while large neurons are difficult to excite but easily inhibited, the
emergence, submergence and amplitude modulation phenomena of the intermediary
rhythm can be explained by straightforward application of conventional concepts of
sequential excitation and inhibition in neuronal pools. In closing the description of
this putative mechanism, it can be assumed that on the one hand, the global efficacy of
the excitatory and inhibitory ionic currents are “integrated” at the axon hillock, where
on the other hand peripheral and central input is either augmenting the probability
of supra-threshold relay excitation or the opposite, namely the hyper-polarization
and subsequent sustained inhibition (a phenomenon also referred to as “occlusion”
in terms of conventional neurodynamics). Anatomy teaches, of course, that there are
145
These variations itself represent an essential physiological property, namely adapting
to order various rhythms in a n:m integer number mode. Thus, the function of this
0.15 Hz rhythm band elicited coupling between cardiovascular and respiration time
series which was enhanced as amplitudes of the 0.15 Hz rhythm in reticular neurons
increased.[4, 18].
Analogies between canine and human were also found in amplitude dynamics.
Spindle wave shaped amplitude modulation epochs were prevalent in the recordings
of the reticular neurons as well as in human recordings of facial skin blood content
oscillations [4, 11–13, 18]. These analogous findings in canine and human lead us
to suggest that the 0.15 Hz rhythm band in facial skin microcirculation of humans
results from coherent oscillatory neuronal activity in the lower brain stem.
In the present communication, we are able to further our understanding of essential
rhythmic principles governing the cardiovascular-respiratory coordination in human.
We demonstrate the interaction between spindles shaped amplitude modulations
of the 0.15 Hz rhythm band and the cardiac attractor. There is an evident inverse
relationship between the power of the spindle and the power of the cardiac 1.2 Hz
frequency band. As spindles reach a maximum, the power of the 1.2 Hz frequency
band becomes distinctly weaker. When lacking amplitude modulations in the 0.15 Hz
rhythm band, the power of the cardiac attractor reaches a maximum. This suggests
closer considerations of the interplay of frequency and amplitude modulations. As for
the dynamics of the frequency dynamics exhibited by the 0.15 Hz rhythm band, we
have expanded our understanding labelling this rhythm since 0.15 Hz is the frequency
precisely between the frequencies of rhythms exhibited by the two branches of the
autonomic nervous system, the sympathetic and parasympathetic nervous system.
We ,therefore, chose to refer to this rhythm as the intermediary rhythm abandoning
a merely phenomenological term in favour of a term which outlines an important
physiological feature.
As this concept of the amplitude modulated „intermediary rhythm” is subjected
to closer scrutiny, it is important to start from the well-known fact that relay neurons
are surrounded by pools of small interneurons. As one further assumes that the latter
are predisposed to function as “inhibitors” (owing to their neurosecretory products,
namely glycine or γ-amino buturylic acid (GABA), it can be insinuated that by mechanisms of “collateral inhibition”, the supra-threshold excitation of any relay neuron
is associated with delayed inhibition due to circulating excitations within the pool of
small interneurons. Furthermore, in assuming that small neurons are easily excited
but poorly inhibited, while large neurons are difficult to excite but easily inhibited, the
emergence, submergence and amplitude modulation phenomena of the intermediary
rhythm can be explained by straightforward application of conventional concepts of
sequential excitation and inhibition in neuronal pools. In closing the description of
this putative mechanism, it can be assumed that on the one hand, the global efficacy of
the excitatory and inhibitory ionic currents are “integrated” at the axon hillock, where
on the other hand peripheral and central input is either augmenting the probability
of supra-threshold relay excitation or the opposite, namely the hyper-polarization
and subsequent sustained inhibition (a phenomenon also referred to as “occlusion”
in terms of conventional neurodynamics). Anatomy teaches, of course, that there are