Active properties of voltage-gated K<sup>+</sup> channels in the cerebellar PCs and their physiological and pathological roles
KV1.4 & KV4 (A-type K+ channel)
Gating propertiesSensitivity for high concentration of 4-AP about 1~10 mM (insensitive for DTX)[607785]
Fast-activating and inactivating channel
Activated at subthreshold voltage around −60 mV
V1/2 activation=−24.9 mV; V1/2 inactivation=−69.2 mV
τdeactivation at −70 mV : 3~4 ms
Impact on excitabilityAcceleration of AP spike
Firing frequency firing pattern (rhythmic Na-Ca spike burst)
Subthreshold variation of membrane properties
Impact on plasticity and learningEyeblink conditioning derives dendritic excitability underlying downregulation of A-type K+ channel[116117]
KV1.1, KV1.2, KV1.6 (D-type K+ channel)
Gating propertiesSensitivity for low concentration of 4-AP about 0.2~1 mM and DTX (2.8~25 nM)[6077]
Low-threshold and non-inactivating channel
Activated at −40~−50 mV
V1/2 activation=−20~−30 mV (KV1.2: −5~5 mV)
τdeactivation=14~23 ms
Impact on excitabilitySpike frequency and adaption, dendritic excitability[8283]
Amplitude and duration of rebound depolarization
Spontaneous bursts
KV3.3 & KV3.4
ExpressionSoma and Dendrite[6970]
Gating propertiesSensitivity for TEA[68]
Rapid activating at suprathreshold and rapidly inactivating channel
Peak amplitude at 30 mV from −70 mV
V1/2 activation=−23.0 mV, τdecay=0.66 ms
Impact on excitabilityRepolarize the membrane potential and maintain repetitive firing[6871]
Dendritic burst firing through Ca2+- Na+ coupling
Impact on plasticity and learningDeletion of KV3.1/3.3 causes ataxic behavior[73]
Exp Neurobiol 2018;27:139~154
© Exp Neurobiol