Experimental Neurobiology

Table 3Active properties of Ca<sup>2+</sup>-activated K<sup>+</sup> channels in the cerebellar PCs and their physiological and pathological roles

SK channel (SK2 subfamily)
Expression	Soma and Dendrite	[90]
Gating properties	Voltage-independent and Ca²⁺dependent channel	[6089]
	Activated by Ca²⁺ influx through P/Q type Ca²⁺ channel
	Sensitivity for apamin (63 pM)
Impact on excitability	Regulation of firing frequency	[13909598]
	Shaping fast afterhyperpolarization (AHP) amplitude
	Climbing fiber-induced spike pause duration
	Activity-dependent modulation of climbing fiber-evoked EPSP amplitude and dendritic local Ca2+ transient
Impact on plasticity and learning	Activity-dependent downregulation of SK channel by eyeblink conditioning	[13118]
Impact on plasticity and learning	Inhibition of SK channel prevents LTP-IE induction	[13118]

BK channel
Expression	Soma and Dendrite	[90]
Gating properties	Voltage- and Ca²⁺-dependent	[60]
Gating properties	V_{1/2 activation}=50 mV at 4 μM [Ca²⁺] to −30 mV at 100 μM [Ca²⁺]	[60]
Impact on excitability	Generation of burst firing through cooperating with K_V3 channels in dendrite	[68919293]
	Climbing fiber-evoked spike pause and burst firing coupled to Ca²⁺ channel
	Shaping medium or slow component of AHP
Impact on plasticity and learning	Dysfunction of SK and BK channels is related to cerebellar ataxia	[94959697]