Untersuchungen über den Rhythmus der Muskelkontraktion

The history of Danish neuroscience

The history of Danish neuroscience starts with an account of impressive contributions made at the 17th century. Thomas Bartholin was the first Danish neuroscientist, and his disciple Nicolaus Steno became internationally one of the most prominent neuroscientists in this period. From the start, Danish neuroscience was linked to clinical disciplines. This continued in the 19th and first half of the 20th centuries with new initiatives linking basic neuroscience to clinical neurology and psychiatry in the same scientific environment. Subsequently, from the middle of the 20th century, basic neuroscience was developing rapidly within the preclinical university sector. Clinical neuroscience continued and was even reinforced during this period with important translational research and a close co-operation between basic and clinical neuroscience. To distinguish 'history' from 'present time' is not easy, as many historical events continue in present time. Therefore, we decided to consider 'History' as new major scientific developments in Denmark, which were launched before the end of the 20th century. With this aim, scientists mentioned will have been born, with a few exceptions, no later than the early 1960s. However, we often refer to more recent publications in documenting the developments of initiatives launched before the end of the last century. In addition, several scientists have moved to Denmark after the beginning of the present century, and they certainly are contributing to the present status of Danish neuroscience-but, again, this is not the History of Danish neuroscience.

The Piper rhythm--a phenomenon related to muscle resonance characteristics?

The purpose of the present work is to examine the causes of the Piper rhythm, i.e. the tendency towards rhytmical 40-60 Hz grouping of motor unit potentials in steadily contracting human muscles. At weak or moderate contraction strength individual motor units exhibited preferred firing rates which were subharmonically related to the Piper rhythm in the gross EMG. Microelectrode muscle nerve recordings provided no support for the hypothesis that the Piper rhythm is dependent on resonance-induced rhythmical volleys of afferent spindle impulses causing reflex entrainment of motor impulses. This hypothesis also seems inconsistent with the findings that Piper rhythms of similar frequency appear in muscles with widely different mechanical properties and that the rhythms are about equally prominent in muscles with brisk as in muscles with weak or absent stretch reflexes. The results suggest that the Piper rhythm is dependent on some kind of pace-maker in the spinal cord or the cerebrum which tends to entrain and synchronize motor impulses.