Pharmacology of the metabotropic glutamate receptor mediated current at the climbing fiber to Purkinje cell synapse.
dc.contributor.author | Zhu, Lan | en |
dc.contributor.author | Strata, Piergiorgio | en |
dc.contributor.author | Andjus, P. R. | en |
dc.date.accessioned | 2015-03-24T16:04:08Z | |
dc.date.available | 2015-03-24T16:04:08Z | |
dc.date.issued | 2005 | |
dc.description.abstract | Different forms of synaptic plasticity in the cerebellum are mediated by metabotropic glutamate receptors (mGluRs). At parallel fiber (PF) to Purkinje cell (PC) synapses activation of mGluR gives rise to a well known slow synaptic current inhibited by antagonists of mGluR1. The distribution of mGluR types in the climbing fiber (CF) to PC synapses is not well known. However, a mGluR1alpha-mediated all-or-none postsynaptic current was also demonstrated at the CF-PC synapse (Dzubay and Otis, Neuron 36, 1159, 2002). Using whole cell patch-clamp recording from PCs in rat cerebellar slices with AMPA receptors blocked and glutamate uptake impaired we demonstrate a more complex pharmacology of a current obtained by single or train CF stimulation. The mGluR1 specific antagonist CPCCOEt in a group of cells suppressed this response while in a similar number of other cells it induced a potentiating effect. The antagonists of mGluR groups II and III (LY341495 and MSOP, respectively) predominantly suppressed the current. The ambiguous effect of CPCCOEt was checked by measuring the paired-pulse depression of the CF EPSC, which was not changed with the antagonist in normal as well as in low (0.5 mM) external Ca(2+) (used to prevent saturation of AMPARs), thus excluding a presynaptic effect. However, CPCCOEt induced a rise in the amplitude (by approximately 50%) as well as a prolongation (p<0.05) of the decay time of CF EPSCs at normal 2 mM Ca(2+), i.e. under conditions of AMPAR saturation, thus indicating an effect of postsynaptic origin. In 0.5 mM Ca(2+) the decay of CF EPSCs was longer but it was also significantly prolonged (p?0.01) by CPCCOEt. However, the CF EPSC amplitude was not significantly affected indicating an underlying Ca(2+)-dependent mechanism. Thus, the pharmacology of the PC mGluR-mediated response points to a dual postsynaptic role of mGluR1 giving rise to a slow postsynaptic current but also regulating other presumably mGluR-dependent currents via second messenger molecules and Ca(2+). The additional electrophysiological role of mGluR II & III types was also indicated. Such a complex regulatory mechanism may have an important role in the mGluR-dependent forms of homosynaptic plasticity and motor learning at the CF-PC synapse. | en |
dc.funder | MIUR | en |
dc.funder | Italian Ministry of Health | en |
dc.funder | 1647 of the Ministry of Science, Republic of Serbia | en |
dc.identifier.citation | Zhu, L., Strata, P. and Andjus, P.R. (2005) Pharmacology of the metabotropic glutamate receptor mediated current at the climbing fiber to Purkinje cell synapse. Progress in brain research, 148, pp. 299-306 | en |
dc.identifier.doi | https://doi.org/10.1016/S0079-6123(04)48023-6 | |
dc.identifier.uri | http://hdl.handle.net/2086/10831 | |
dc.language.iso | en | en |
dc.peerreviewed | Yes | en |
dc.projectid | Scientific research | en |
dc.publisher | Elsevier | en |
dc.researchinstitute | Leicester Institute for Pharmaceutical Innovation - From Molecules to Practice (LIPI) | en |
dc.subject | Pharmacology | en |
dc.subject | Cerebellum | en |
dc.subject | Climbing fibre | en |
dc.subject | Purkingje cell | en |
dc.subject | metabotropic glutamate receptore | en |
dc.title | Pharmacology of the metabotropic glutamate receptor mediated current at the climbing fiber to Purkinje cell synapse. | en |
dc.type | Article | en |
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