Some Preliminary Observations on the Effects of Cations on Conduction Processes in the Abdominal Nerve Cord of The Stick Insect, Carausius Morosus

Abstract

1. In the haemolymph of the stick insect Carausius morosus the concentration of potassium exceeds that of sodium and the concentration of magnesium exceeds that of calcium. The implications of this situation for nerve conduction have been studied. 2. Conduction is maintained in intact and desheathed preparations of the fourth adbominal ganglion under irrigation with a solution resembling haemolymph in ionic composition. 3. Action potentials recorded in response to electrical stimulation of the nerve cord decline in sodium-free solutions, both in intact and in desheathed preparations. 4. Conduction declines slowly under irrigation with magnesium-free solutions both in intact and in desheathed preparations.