Inhibition of excitatory synaptic transmission in the trigeminal motor nucleus by the nitric oxide-cyclicGMP signaling pathway

►NO donors reduced evoked glutamatergic synaptic currents in trigeminal motoneurons. ►NO donor effects were enhanced by guanylate cyclase sensitizers and mimicked by cGMP. ►Postsynaptic actions of glutamate were not reduced by NO or cGMP. ►Paired pulse facilitation was enhanced and failure rate was decreased by NO. ►NO through cGMP presynaptically inhibits glutamatergic transmission to motoneurons.