Involvement of presynaptic N-methyl-D-aspartate receptors in cerebellar long-term depression.
At the cerebellar synapses between parallel fibers (PFs) and Purkinje cells (PCs), long-term depression (LTD) of the excitatory synaptic current has been assumed to be independent of the N-methyl-D-aspartate (NMDA) receptor activation because PCs lack NMDA receptors. However, we now report that LTD is suppressed by NMDA receptor antagonists that act on presynaptic NMDA receptors of the PFs. This effect is still observed when the input is restricted to a single fiber. Therefore, LTD does not require the spatial integration of multiple inputs. In contrast, it involves a temporal integration, since reliable LTD induction requires the PFs to fire two action potentials in close succession. This implies that LTD will selectively depress the response to a burst of presynaptic action potentials.
Casado
Mariano
M
Laboratoire de Neurobiologie, CNRS UMR 8544, Ecole Normale Supérieure, 46 rue d'Ulm, 75005 Paris, France. casado@wotan.ens.fr
Isope
Philippe
P
Ascher
Philippe
P
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D017729:Presynaptic Terminals / Q000187:drug effects / Q000378:metabolism*; D011689:Purkinje Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
D002614:Chelating Agents; D004791:Enzyme Inhibitors; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D009569:Nitric Oxide; D018698:Glutamic Acid; D002118:Calcium