Routes of tetanus toxin entrance into the central nervous system and some problems in the pathogenesis of experimental tetanus

Abstract

As shown in experiments on albino rats, the principal route of entry into the spinal cord for tetanus toxin is through anterior roots. Apart from the latter, the toxin is detected in the nerves of extremity and spinal ganglia on the side of toxin administration. The toxin was undetectable in the posterior roots, and could not be revealed in the nerves, ganglia and roots of the contralateral side, after injecting it in a dose of 10–15 DLM. The data obtained coincide with the results of previous investigations. Both demonstrated that only preliminary deafferentation (as distinct from deafferentation) of the extremity, into the muscles of which the toxin was injected, prevented the development of general tetanus with the circulatory path of the toxin spread blocked by means of tetanus antiserum. The changes in the electric activity of the muscle (EA) into which the toxin was injected were examined at various intervals after its administration. As demonstrated, the changes in the EA occur only after the toxin reaches the anterior horns of the spinal cord. No changes in the EA were noted prior to this period, even with the toxin present in the muscle for several hours. The results of the above-mentioned investigations confirm former conclusions and are in accordance with the inferences of other authors, namely that the main pathogenetic mechanism invclved in the development of local and general tetanus is the central and not the peripheral action of the toxin. The possible routes of toxin progress along the nerve are discussed.