The role of small-conductance Ca2+-activated K+ channels in the modulation of 4-aminopyridine-induced burst firing in rat cerebellar Purkinje cells.

摘要: Abstract Small-conductance Ca 2+ -activated K + channels (SK) regulate the firing properties of many types neurons. In mammalian brain, 3 subunits (SK1–SK3) are expressed with different distributions. Purkinje cells (PCs), central neuron cerebellar basic circuit, express SK2 subunit in their soma and dendrites. Mature PCs fire bursts Na –Ca spikes that constitute sole output cortex. Application 4-aminopyridine (4-AP), blocker Kv potassium brain slices, augments electrical activity burst mature PCs. Using conventional intracellular recordings from acutely prepared we examined role SK regulation 4-AP-induced apamin, induced a depolarization membrane potential particularly between spontaneous by 4-AP. To study burst, was suppressed injecting adequate hyperpolarizing current were evoked depolarizing pulse. Apamin decreased duration 4-AP-treated It also prolonged repolarization time number interval bursts. Decrease seen rebound responses. Our findings suggest active at potentials close to resting play an important neuronal hyperexcitability firing.