Criteria have been offered to define whether a phenomenon can be judged as neurotropic. One of the main points was that axons must be viewed en route to a target, and subject to a gradient of diffusible substance. In experiments which are analyzed at a later time period, specificity may be clearly demonstrated; but it is difficult to evaluate the mechanism by which that specificity was generated, without actually observing axons on the way to a target. In addition, a hierarchy of types of specificity in nerve regeneration was discussed, beginning at the most general level with tissue specificity, sensory vs. motor specificity, topographic, and end-organ specificity. Formal discussions fell more or less into two categories. Several examined sensory and motor specificity, especially the presentations of Drs. Ochi, Maki, and Green. The results of these studies were disparate and not in agreement. It is clear that we need to know specific details of every model, before we can understand why different results were obtained. Several of the other discussions concerned topographic specificity, both at the motor and sensory level. The conclusion of the presentations by Drs. Zhao, Carlstedt, Hems and Green, was that there is a lack of topographic specificity at the nerve-trunk level, in both motor and sensory systems. The nerve-grafting experiments of Dr. Frey could also be viewed in a sensory- motor context and as confirming earlier work, which has shown that motor axons will regenerate, when necessary, in a sensory conduit over a long distance.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of reconstructive microsurgery|
|State||Published - Jan 1 1994|
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