Properties and roles of BKCa channels in cultured cerebellar granule neuron: Experimental and simulation studies

We studied the properties and roles of large-conductance calcium-sensitive potassium channels (BKCa) in cultured rat cerebellar granule neurons. In intact cells these channels had chord conductances of 130–200 pS. The conductance, threshold for channel activation and the mean open time and open probability depend on the age of cells. In computer simulations the elimination of BKCa channel decreases the maximum and minimum peak values of an action potential, causes reduced hyperpolarization and increases firing frequency. The observed alterations may be linked to the complexity of granule neuron excitability during maturation and provide new insight into modeling the developmental changes in small CNS neurons.