[Transformation of electrical activity in the myelinated nerve fibres of amphibia by 4-aminopyridine].
Using the extracellular recording we studied the effect of 4-aminopyridine (4-AP), a potassium channel blocker on the electrical activity of the myelinated nerve fibres of amphibia Rana ridibunda Pallas. Two main types of the reaction on 4-AP were established: extension of the action potential and multi-spike response. In some cases the nerve fibres with multi-spike response generated spontaneous activity without stimulation in the form of bursts of action potentials. During repetitive stimulation 4-AP decreased after-depolarization (at the beginning of the stimulation), the posttetanic after-depolarization and the development of posttetanic after-hyperpolarization. Using the paired stimulation it was established that the spike and after-depolarization of the second action potential depended on the size of after-depolarization after the first action potential. The effects of 4-AP were strongly time-dependent.
Kuznetzova
I V
IV
Evstigneev
D A
DA
Glukhova
N V
NV
D015761:4-Aminopyridine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D009413:Nerve Fibers, Myelinated / Q000187:drug effects* / Q000502:physiology; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D011895:Rana ridibunda
D026902:Potassium Channel Blockers; D015761:4-Aminopyridine