Participation of low-threshold Ca2+ spike in the Purkinje cells complex spike.
In Purkinje cells from cerebellar slice cultures, low-threshold Ca spike (LTS) gives rise to complex bursts in the soma that resemble the complex spike induced by climbing fibers stimulation. We show that LTS is reduced by T-type and R-type Ca channel blockers (SNX-482, nickel, or mibefradil). We propose that LTS is generated by openings of T-type Ca channels (alpha-1G and/or alpha-1I subunits) and R-type Ca channels (alpha-1E subunit isoforms with a weak sensitivity to SNX-482 and to nickel). Using mibefradil we show that climbing fiber stimulation activates LTS, which contributes to the shape of the response. This Ca entry may be involved in Ca-dependent synaptic plasticity of the parallel fiber input induced by climbing fiber activation.
Cavelier
Pauline
P
Department de Neurotransmission et Sécrétion Neuroendocrine, UMR7168-LC2 CNRS-Université L. Pasteur, rue Blaise Pascal, F-67084 STRASBOURG cedex, France.
Lohof
Ann M
AM
Lonchamp
Etienne
E
Beekenkamp
Huguette
H
Mariani
Jean
J
Bossu
Jean-Louis
JL
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000187:drug effects; D020908:Calcium Channels, R-Type / Q000187:drug effects; D020013:Calcium Signaling / Q000502:physiology*; D004594:Electrophysiology; D018698:Glutamic Acid / Q000378:metabolism; D020748:Mibefradil / Q000494:pharmacology; D009412:Nerve Fibers / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects; D009532:Nickel / Q000494:pharmacology; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D010775:Photic Stimulation; D011689:Purkinje Cells / Q000502:physiology*; D051381:Rats; D013111:Spider Venoms / Q000494:pharmacology
D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D020908:Calcium Channels, R-Type; C115521:SNX 482; D013111:Spider Venoms; D020748:Mibefradil; D018698:Glutamic Acid; D009532:Nickel