Pairing-specific long-term depression prevented by blockade of PKC or intracellular Ca2+.
Long-term depression was established in cerebellar Purkinje cells using 20 pairings of a brief, high frequency train of parallel fiber stimulation with a subsequent 100 ms depolarizing current injection. Effects were assessed on the peak amplitude of Purkinje cell excitatory post synaptic potentials (EPSPs) elicited by single parallel fiber test pulses. Intradendritically recorded Purkinje cell EPSPs exhibited long-term (>20 min) reduction in peak amplitude following paired stimulation but not if pretreated with the protein kinase C inhibitor calphostin C or iontophoretically injected with the calcium chelator EGTA. The similarity of the stimulation protocol and behavioral conditioning paradigms suggests pairing-specific long-term synaptic depression is a valuable model for understanding the cellular mechanisms underlying cerebellar cortical contributions to learning.
Freeman
J H
JH
Department of Psychology, The University of Iowa, Iowa City 52242, USA.
Shi
T
T
Schreurs
B G
BG
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D002614:Chelating Agents / Q000494:pharmacology; D003712:Dendrites / Q000187:drug effects; D004533:Egtazic Acid / Q000494:pharmacology; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects*; D066298:In Vitro Techniques; D007478:Iontophoresis; D008297:Male; D009281:Naphthalenes / Q000494:pharmacology; D009473:Neuronal Plasticity / Q000187:drug effects*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D011689:Purkinje Cells / Q000187:drug effects; D011817:Rabbits
D002614:Chelating Agents; D004791:Enzyme Inhibitors; D009281:Naphthalenes; D004533:Egtazic Acid; D011493:Protein Kinase C; C058819:calphostin C; D002118:Calcium