Differential long-lasting potentiation of the NMDA and non-NMDA synaptic currents induced by metabotropic and NMDA receptor coactivation in cerebellar granule cells.
Whole-cell patch-clamp recordings in rat cerebellar slices were used to investigate the effect of metabotropic glutamate receptor activation on mossy fibre-granule cell synaptic transmission. Transient application of 20 microM 1S, 3R-aminocyclopentane-1, 3-dicarboxylic acid simultaneously with low-frequency NMDA receptor activation induced long-lasting non-decremental potentiation of both NMDA and non-NMDA receptor-mediated synaptic transmission. Potentiation could be prevented by application of the metabotropic glutamate receptor antagonist (+)-O-methyl-4-carboxyphenyl-glycine at 500 microM. Characteristically, NMDA potentiation was two to three times as large as non-NMDA current potentiation, occurred only in a slow subcomponent, and was voltage-independent. This result demonstrates a pivotal role of NMDA receptors in the metabotropic potentiation of transmission, which may be important in regulating cerebellar information processing.


BACKGROUND
cerebellum, LTP, metabotropic receptors, NMDA receptors, patch-clamp, rat
rossi
P
P
Istituto di Fisiologia Generale, Via Forlanini 6, 1-27100, Pavia, Italy.
D'Angelo
E
E
Taglietti
V
V
D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects*; D003515:Cycloleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation; D009474:Neurons / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects*
D001565:Benzoates; D018691:Excitatory Amino Acid Antagonists; D018094:Receptors, Metabotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; C079694:alpha-methyl-4-carboxyphenylglycine; D005998:Glycine