SK2 channel modulation contributes to compartment-specific dendritic plasticity in cerebellar Purkinje cells.
Small-conductance Ca(2+)-activated K(+) channels (SK channels) modulate excitability and curtail excitatory postsynaptic potentials (EPSPs) in neuronal dendrites. Here, we demonstrate long-lasting plasticity of intrinsic excitability (IE) in dendrites that results from changes in the gain of this regulatory mechanism. Using dendritic patch-clamp recordings from rat cerebellar Purkinje cells, we find that somatic depolarization or parallel fiber (PF) burst stimulation induce long-term amplification of synaptic responses to climbing fiber (CF) or PF stimulation and enhance the amplitude of passively propagated sodium spikes. Dendritic plasticity is mimicked and occluded by the SK channel blocker apamin and is absent in Purkinje cells from SK2 null mice. Triple-patch recordings from two dendritic sites and the soma and confocal calcium imaging studies show that local stimulation limits dendritic plasticity to the activated compartment of the dendrite. This plasticity mechanism allows Purkinje cells to adjust the SK2-mediated control of dendritic excitability in an activity-dependent manner.
Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA.
Gen
G
Ohtsuki
Claire
C
Piochon
John P
JP
Adelman
Christian
C
Hansel
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001030:Apamin / Q000494:pharmacology; D002451:Cell Compartmentation / Q000187:drug effects / Q000502:physiology; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D003712:Dendrites / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D011689:Purkinje Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000037:antagonists & inhibitors / Q000502:physiology*
C496898:Kcnn2 protein, mouse; D051640:Small-Conductance Calcium-Activated Potassium Channels; D001030:Apamin