J Physiol Volume 578, Number 2, 545-550, January 15, 2007 DOI: 10.1113/jphysiol.2006.115014
Short- and long-term depression of rat cerebellar parallel fibre synaptic transmission mediated by synaptic crosstalk
Païkan Marcaggi1 and
David Attwell1
1 Department of Physiology, University College London, Gower Street, London WC1E 6BT, UK
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.
(Received 8 June 2006;
accepted after revision 13 November 2006;
first published online 16 November 2006)
Corresponding author P. Marcaggi: Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, UK. Email: p.marcaggi{at}ucl.ac.uk
Copyright © 2007 The Physiological Society.