Protection of Synaptic Transmission Against Block by Nicotine

Abstract

During the past year we have studied the effects of various drugs on synaptic transmission in the crayfish; the results will be described elsewhere. In the course of this investigation many drugs were found to have no effect. In such cases a check was made on the preparation by applying a dose of nicotine (10^(-5) grams/cc.) 10 minutes after the original drug. Control tests had shown that nicotine in this concentration blocks transmission in 1-2 minutes. As expected, the presence of most drugs did not influence this action. With some, however, either the nicotine was without effect or the block was greatly delayed. Evidently under certain conditions the preparation is protected against the action of nicotine. Since this situation seems to be of considerable interest, the following preliminary report is presented at this time.