Presynaptic CB1 receptors regulate synaptic plasticity at cerebellar parallel fiber synapses.
Journal of Neurophysiology. 2011-02-01; 105(2): 958-963
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1. J Neurophysiol. 2011 Feb;105(2):958-63. doi: 10.1152/jn.00980.2010. Epub 2010 Nov
Presynaptic CB1 receptors regulate synaptic plasticity at cerebellar parallel
Carey MR(1), Myoga MH, McDaniels KR, Marsicano G, Lutz B, Mackie K, Regehr WG.
(1)Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston,
MA 02115, USA.
Endocannabinoids are potent regulators of synaptic strength. They are generally
thought to modify neurotransmitter release through retrograde activation of
presynaptic type 1 cannabinoid receptors (CB1Rs). In the cerebellar cortex, CB1Rs
regulate several forms of synaptic plasticity at synapses onto Purkinje cells,
including presynaptically expressed short-term plasticity and, somewhat
paradoxically, a postsynaptic form of long-term depression (LTD). Here we have
generated mice in which CB1Rs were selectively eliminated from cerebellar granule
cells, whose axons form parallel fibers. We find that in these mice,
endocannabinoid-dependent short-term plasticity is eliminated at parallel fiber,
but not inhibitory interneuron, synapses onto Purkinje cells. Further, parallel
fiber LTD is not observed in these mice, indicating that presynaptic CB1Rs
regulate long-term plasticity at this synapse.
PMID: 21084685 [Indexed for MEDLINE]