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In this second edition, the authors present a thorough, advanced review of the interactions between motoneurones and muscles in vertebrates. The book discusses the significance of nerve-muscle interactions for the normal development and maintenance of the vertebrate neuromuscular system and reviews the consequences of their disruption. The plasticity of nerve-muscle interactions and the potential for repair is analyzed, as is the importance of neuromuscular activity in development. The subject is approached from a broad viewpoint and the authors integrate results from many disciplines to illustrate the significance of neuromuscular interaction for normal locomotor activity. This approach makes the book useful for clinical researchers of neuromuscular disease.
The first evidence that electrical changes can cause muscles to contract was p- vided by Galvani (1791). Galvani's ideas about 'animal electricity' were explored during the 19th and 20th century when it was firmly established that 'electricity' is one of the most important mechanisms used for communication by the nervous system and muscle. These researches lead to the development of ever more soph- ticated equipment that could either record the electrical changes in nerves and muscles, or elicit functional changes by electrically stimulating these structures. It was indeed the combination of these two methods that elucidated many of the basic principles about the function of the nervous system. Following these exciting findings, it was discovered that electrical stimulation and the functions elicited by it also lead to long-term changes in the properties of nerves and particularly muscles. Recent findings help us to understand the mec- nisms by which activity induced by electrical stimulation can influence mature, fully differentiated cells, in particular muscles, blood vessels and nerves. Electrically elicited activity determines the properties of muscle fibres by activating a sequence of signalling pathways that change the gene expression of the muscle. Thus, elect- cal activity graduated from a simple mechanism that is used to elicit muscle c- traction, to a system that could induce permanent changes in muscles and modify most of its characteristic properties.
Now almost eighty years old, Gerta Vrbova recalls the dramatic events in Slovakia and Hungary between 1939 and 1945 which saw many of his relations, friends and neighbours perish in the Nazi gas chambers."
In the second century, Galen recognized that nerve and muscle were functionally inseparable since contraction of muscle occurred only if the nerves supplying that muscle were intact. He therefore concluded that the shortening of a muscle was controlled by the central nervous sytem while the extension of a muscle could occur in the absence of innervation. Nerves, he thought, were the means of transport for animal spirits to the muscles; the way in which animal spirits may bring about contraction dominated the study of muscle physiology from that time until the historical discovery of Galvani that muscle could be stimulated electrically and that nerve and muscle were themselves a source of electrical energy. It is now well known that nerves conduct electrically and that transmission from nerve to striated muscle is mediated by the chemical which is liberated from nerve terminals onto the muscle membrane. In vertebrates this chemical is acetylcholine (ACh). Thus the concept of spirits that are released from nerves and control muscle contraction directly, is no longer tenable. Nevertheless the concept of 'substances' transported down nerv~s which directly control many aspects of muscle has not been abandoned, and has in fact been frequently reinvoked to account for the long-term regula tion of many characteristics of muscle (see review by Gutmann, 1976) and for the maintenance of its structural integrity.
In many cases of neuromuscular disorders the physician is faced with a complete lack of therapeutic approaches. This helplessness places the doctor in a position of conflict between his desire to help and his awareness that there is no treatment. In this situation it is tempting to indiscriminately use any procedure that avoids an admission of medical helplessness while satisfying the patient's demand for treatment. Electrical interventions are often used to avoid this situation. Due to the random use of therapeutic approaches it is not known what really happens. Presumptions and biased empirical observations have led to the exten sive use of different forms of electrical stimulation regimes in neuromuscular diseases. Due to this unsatisfactory situation it is necessary to know more about appropriate methods that are being used in particular disorders. The search for a better understanding of nerve-muscle interaction has shown that certain activity patterns can influence muscle. These experi mental results provide a rational basis for a possible therapeutic use of electrical stimulation of nerve and muscle. Previously most research has been conducted in normal tissue, and little is known regarding the re sponses of diseased muscle. In an interdisciplinary approach to this, it is our intention to present the current knowledge about basic principles of electrical stimulation in normal muscle. Before electrical stimulation can be accepted as a therapeutic tool, we felt it necessary to summarize the effects of activity in normal and diseased muscle and nerve."
The first evidence that electrical changes can cause muscles to contract was p- vided by Galvani (1791). Galvani's ideas about 'animal electricity' were explored during the 19th and 20th century when it was firmly established that 'electricity' is one of the most important mechanisms used for communication by the nervous system and muscle. These researches lead to the development of ever more soph- ticated equipment that could either record the electrical changes in nerves and muscles, or elicit functional changes by electrically stimulating these structures. It was indeed the combination of these two methods that elucidated many of the basic principles about the function of the nervous system. Following these exciting findings, it was discovered that electrical stimulation and the functions elicited by it also lead to long-term changes in the properties of nerves and particularly muscles. Recent findings help us to understand the mec- nisms by which activity induced by electrical stimulation can influence mature, fully differentiated cells, in particular muscles, blood vessels and nerves. Electrically elicited activity determines the properties of muscle fibres by activating a sequence of signalling pathways that change the gene expression of the muscle. Thus, elect- cal activity graduated from a simple mechanism that is used to elicit muscle c- traction, to a system that could induce permanent changes in muscles and modify most of its characteristic properties.
Following injury or disease, neural circuitry can be altered to
varying degrees leading to highly individualized characteristics
that may or may not resemble original function. In addition, lost
or partially damaged circuits and the effects of biological
recovery processes coupled with learned compensatory strategies
create a new neuroanatomy with capabilities that are often not
functional or may interfere with daily life. To date, the majority
of approaches used to treat neurological dysfunction have focused
on the replacement of lost or damaged function, usually through the
suppression of surviving neural activity and the application of
mechanical assistive devices. Restorative Neurology of Spinal Cord
Injury offers a different and novel approach.
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