Effect of chloramine-T and N-bromsuccinimide on intracellular and extracellular action potentials from unmyelinated...

The change in intracellular (ICAPs) and extracellular (ECAPs) potentials of unmyelinated axons of Lumbricus terrestris under the effect of Chloramine-T (CT) and N-Bromsuccinimide (NBS), applied extracellularly, is studied. Delay of the repolarization phase of ICAPs was found under the effect of NBS, as well as slight decrease of the amplitude of ICAPs and ECAPs, with an insignificant decrease in the propagation velocity of the excitation. The first (V') and second (V") time derivatives and the total ionic current (Ii) are calculated from the intracellular action potential in norm and under the effect of NBS. A delay of the inactivation phase of the inward sodium current and a decrease of the amplitude of the total ionic current, calculated from ICAP, were found. Under the effect of CT there was a decrease in the amplitude of the action potentials, without a delay in the repolarization phase and the propagation velocity of the excitation decreases. CT leads to lasting inhibition of the excitability of the axon under prolonged impact (20 min).