Effects of some divalent cations on motoneurones in cats

摘要: In cats under Dial, Co, Mn, La, and Sr were injected extracellularly near lumbosacral motoneurones. All tended to improve intracellular recording, but when the membrane potential was initially stable, especially had a moderate reproducible depolarizing action. Both Mn Co depressed excitatory postsynaptic potentials evoked by dorsal root stimulation. The prominent after-hyperpolarization (a.h.p.), which normally follows motoneuronal action potential, consistently reversibly (as well as La), underlying conductance increase being also diminished, there no significant reduction in after-depolarization. By contrast, potentiate a.h.p., this previous injection of or Mn. Unlike other cations, marked depressant effect on particularly its rate rise. Since could be immediately restored hyperpolarization an (in...