TY - JOUR T1 - Anandamide, Cannabinoid Type 1 Receptor, and NMDA Receptor Activation Mediate Non-Hebbian Presynaptically Expressed Long-Term Depression at the First Central Synapse for Visceral Afferent Fibers JF - The Journal of Neuroscience JO - J. Neurosci. SP - 12627 LP - 12637 DO - 10.1523/JNEUROSCI.1028-13.2013 VL - 33 IS - 31 AU - Abdessattar Khlaifia AU - Hanad Farah AU - Florian Gackiere AU - Fabien Tell Y1 - 2013/07/31 UR - http://www.jneurosci.org/content/33/31/12627.abstract N2 - Presynaptic long-term depression (LTD) of synapse efficacy generally requires coordinated activity between presynaptic and postsynaptic neurons and a retrograde signal synthesized by the postsynaptic cell in an activity-dependent manner. In this study, we examined LTD in the rat nucleus tractus solitarii (NTS), a brainstem nucleus that relays homeostatic information from the internal body to the brain. We found that coactivation of N-methyl-D-aspartate receptors (NMDARs) and type 1 cannabinoid receptors (CB1Rs) induces LTD at the first central excitatory synapse between visceral fibers and NTS neurons. This LTD is presynaptically expressed. However, neither postsynaptic activation of NMDARs nor postsynaptic calcium influx are required for its induction. Direct activation of NMDARs triggers cannabinoid-dependent LTD. In addition, LTD is unaffected by blocking 2-arachidonyl-glycerol synthesis, but its induction threshold is lowered by preventing fatty acid degradation. Altogether, our data suggest that LTD in NTS neurons may be entirely expressed at the presynaptic level by local anandamide synthesis. ER -