Short- and long-term depression of rat cerebellar parallel fibre synaptic transmission mediated by synaptic crosstalk.
Cerebellar granule cell to Purkinje cell synapses have been reported to show plasticity when stimulating the parallel fibres, but not when granule cell axons are stimulated in the granular layer. The latter absence of plasticity has been attributed either to the synapses made by ascending granule cell axons lacking some feature needed to evoke plasticity, such as metabotropic glutamate receptors, or to spillover of glutamate between adjacent active synapses being essential for plasticity to occur and having a greater effect for parallel fibre stimulation than for granular layer stimulation. Here we show that both long-term depression (LTD) and endocannabinoid plasticity can depend on interaction between adjacent synapses. These results focus attention on the need to characterize the spatial pattern of parallel fibre activity evoked by physiological stimuli, in order to assess the conditions under which synaptic plasticity will occur in vivo.
Marcaggi
Païkan
P
Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, UK. p.marcaggi@ucl.ac.uk
Attwell
David
D
D000818:Animals; D063385:Cannabinoid Receptor Modulators / Q000502:physiology; D002531:Cerebellum / Q000166:cytology / Q000502:physiology*; D002867:Chromones / Q000494:pharmacology; D036881:Long-Term Synaptic Depression / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D009412:Nerve Fibers; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D011689:Purkinje Cells / Q000502:physiology; D051381:Rats; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*
C117789:7-(hydroxyimino)cyclopropan(b)chromen-1a-carbxoylic acid ethyl ester; D063385:Cannabinoid Receptor Modulators; D002867:Chromones; D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1