Postsynaptic current mediated by metabotropic glutamate receptors in cerebellar Purkinje cells

被引:123
作者
Tempia, F [1 ]
Miniaci, MC [1 ]
Anchisi, D [1 ]
Strata, P [1 ]
机构
[1] Univ Turin, Dept Neurosci, I-10125 Turin, Italy
关键词
D O I
10.1152/jn.1998.80.2.520
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
In rat cerebellar slices, repetitive parallel fiber stimulation evokes an inward, postsynaptic current in Purkinje cells with a fast component mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors and a slower component mediated by metabotropic glutamate receptors (mGluR). The mGluR-mediated excitatory postsynaptic current (mGluR-EPSC) is evoked selectively by parallel fiber stimulation; climbing fiber stimulation is ineffective. The mGluR-EPSC is elicited most effectively with increasing frequencies of parallel fiber stimulation, from a threshold of 10 Hz to a maximum response at similar to 100 Hz. The amplitude of the mGluR-EPSc is a linear function of the number of stimulus pulses without any apparent saturation, even with >10 pulses. Thus mGluRs at the parallel fiber-Purkinje cell synapse can function as linear detectors of the number of spikes in a burst of activity in parallel fibers. The mGluR-EPSC is present from postnatal day 15 and persists into adulthood. It is inhibited by the generic mGluR antagonist (RS)-a-methyl-4-carboxyphenylglycine and by the group I mGluR antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid at a concentration selective for mGluR1. Although the intracellular transduction pathway involves a G protein, the putative mediators of mGluR1 (phospholipase C and protein kinase C) are not directly involved, indicating that the mGluR-EPSC studied here is mediated by a different and still unidentified second-messenger pathway. Heparin, a nonselective antagonist of inositol-trisphosphate (IP3) receptors, has no significant effect on the mGluR-EPSC, suggesting that also IP3 might be not required for the response. buffering intracellular Ca2+ with a high concentration of bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid partially inhibits the mGluR-EPSC, indicating that Ca2+ is not directly responsible for the response but that resting Ca2+ levels exert a tonic potentiating effect on the mGluR-EPSC.
引用
收藏
页码:520 / 528
页数:9
相关论文
共 52 条
[1]   REDUCED HIPPOCAMPAL LONG-TERM POTENTIATION AND CONTEXT-SPECIFIC DEFICIT IN ASSOCIATIVE LEARNING IN MGLUR1 MUTANT MICE [J].
AIBA, A ;
CHEN, C ;
HERRUP, K ;
ROSENMUND, C ;
STEVENS, CF ;
TONEGAWA, S .
CELL, 1994, 79 (02) :365-375
[2]   SYNAPTIC ACTIVATION OF METABOTROPIC GLUTAMATE RECEPTORS IN THE PARALLEL FIBER-PURKINJE CELL PATHWAY IN RAT CEREBELLAR SLICES [J].
BATCHELOR, AM ;
MADGE, DJ ;
GARTHWAITE, J .
NEUROSCIENCE, 1994, 63 (04) :911-915
[3]   Pharmacological characterization of synaptic transmission through mGluRs in rat cerebellar slices [J].
Batchelor, AM ;
Knopfel, T ;
Gasparini, F ;
Garthwaite, J .
NEUROPHARMACOLOGY, 1997, 36 (03) :401-403
[4]   NOVEL SYNAPTIC POTENTIALS IN CEREBELLAR PURKINJE-CELLS - PROBABLE MEDIATION BY METABOTROPIC GLUTAMATE RECEPTORS [J].
BATCHELOR, AM ;
GARTHWAITE, J .
NEUROPHARMACOLOGY, 1993, 32 (01) :11-20
[5]   The synaptic potential mediated by metabotropic glutamate receptors is not associated with a substantial elevation of cytosolic free calcium concentration in Purkinje cells [J].
Batchelor, AM ;
Vranesic, I ;
DelPrincipe, F ;
Garthwaite, J ;
Knopfel, T .
NEUROREPORT, 1996, 7 (12) :1949-1952
[6]   Frequency detection and temporally dispersed synaptic signal association through a metabotropic glutamate receptor pathway [J].
Batchelor, AM ;
Garthwaite, J .
NATURE, 1997, 385 (6611) :74-77
[7]  
BERRIDGE MJ, 1996, COINCIDENCE DETECTIO, P22
[8]   Expression and coupling to polyphosphoinositide hydrolysis of group I metabotropic glutamate receptors in early postnatal and adult rat brain [J].
Casabona, G ;
Knopfel, T ;
Kuhn, R ;
Gasparini, F ;
Baumann, P ;
Sortino, MA ;
Copani, A ;
Nicoletti, F .
EUROPEAN JOURNAL OF NEUROSCIENCE, 1997, 9 (01) :12-17
[9]   METABOTROPIC GLUTAMATE RECEPTORS ARE DIFFERENTIALLY REGULATED DURING DEVELOPMENT [J].
CATANIA, MV ;
LANDWEHRMEYER, GB ;
TESTA, CM ;
STANDAERT, DG ;
PENNEY, JB ;
YOUNG, AB .
NEUROSCIENCE, 1994, 61 (03) :481-495
[10]  
CONDORELLI DF, 1992, MOL PHARMACOL, V41, P660