Experimentelle Beiträge zum Problem der Reizleitung im Nerven

Periodic solutions and refractory periods in the soliton theory for nerves and the locust femoral nerve

“…However, for a real nerve of finite length the overall length of the nerve should decrease while a nerve pulse is traveling along the axon. Such length changes have been observes in isolated nerves [6,14]. However, it seems unlikely that a nerve within a body can undergo significant length changes because they are attached to muscles or other nerves with more or less fixed positions.…”

“…of localized pulses, exists. This model automatically addresses the observed changes in length [6] and [14] and thickness [32,16,33,34,14,35] and the reversible heat production [10,11,13,14,36].…”

“…The initial heat release during the action potential was also found to be much larger than the free energy required to charge the membrane capacitor, which rules out the possibility that a purely electrical picture is able to explain the nerve signal. The picture of the nerve pulse as an electromechanical phenomenon is further supported by the finding of mechanical changes of the nerve under the influence of the action potential, including changes in thickness and length (e.g., [6,16,14]). …”

“…An immediate consequence is that the excited nerve contracts. This has been observed in isolated nerves [6,14]. However, it is difficult to imagine that nerves also contract in the native situation when they are embedded in tissue where distances are kept constant.…”

“…Although the propagation of mechanical pulses in nerves has been discussed before [5,6,7,8,9], we have provided an quantitative formalism based on thermodynamics for how such pulses are generated and how they propagate. An important justification for the assumption of an electromechanical process is the experimental observation of reversible heat changes in phase with the action potential and a zero net heat release during the action potential (e.g., [10,11,12,13,14]).…”