Abstract
Collateral inhibition in the goldfish Mauthner cell consists of three different types of inhibition, i. e., the electrical inhibition, postsynaptic inhibition acting on the soma, and the third type of inhibition. The last one acts on presynaptic elements and on the lateral dendrite. Effects of strychnine and procaine, administered intramuscularly, were selective among these different types of inhibition. Strychnine blocked postsynaptic inhibition acting on the soma as well as the third type of inhibition leaving the electrical inhibition little suppressed, while procaine selectively blocked the electrical inhibition and the postsynaptic inhibition acting on the soma sparing the third type of inhibition. Possible mechanisms as well as loci of action of two drugs were discussed based upon these findings.
