Long-term desensitization of quisqualate-specific glutamate receptors in Purkinje cells investigated with wedge recording from rat cerebellar slices.
Responses of Purkinje cells to quisqualate and aspartate were examined in rat cerebellar slices with a 'wedge' recording technique. Conditioning with bath application of 100 microM quisqualate for 1 or 4 min frequently induced reduction of Purkinje cell responses to testing bath application of 100 microM quisqualate. Test responses obtained at 5-30 min intervals were 79% after 1 min conditioning and 64% after 4 min conditioning, relative to conditioning responses. Since there was no correlation between the degree of reduction and the conditioning-testing interval, the effect of conditioning appeared to be sustained over 30 min. No such desensitization was observed with 3 or 5 mM aspartate. The presently demonstrated desensitization of quisqualate-specific glutamate receptors could represent a central mechanism of the 'long-term depression' type of synaptic plasticity in Purkinje cells.
Ito
M
M
Laboratory for Neural Networks, Frontier Research Program, RIKEN, Wako, Japan.
Karachot
L
L
D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D010069:Oxadiazoles / Q000494:pharmacology*; D011689:Purkinje Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D016318:Quisqualic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter / Q000187:drug effects* / Q000502:physiology
D010069:Oxadiazoles; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter; D001224:Aspartic Acid; D016318:Quisqualic Acid