TY - JOUR T1 - Presynaptic Kainate Receptor Activation Is a Novel Mechanism for Target Cell-Specific Short-Term Facilitation at Schaffer Collateral Synapses JF - The Journal of Neuroscience JO - J. Neurosci. SP - 10796 LP - 10807 DO - 10.1523/JNEUROSCI.2746-06.2006 VL - 26 IS - 42 AU - Hua Yu Sun AU - Lynn E. Dobrunz Y1 - 2006/10/18 UR - http://www.jneurosci.org/content/26/42/10796.abstract N2 - Target cell-specific differences in short-term plasticity have been attributed to differences in the initial release probability of synapses. Using GIN (GFP-expressing inhibitory neurons) transgenic mice that express enhanced green fluorescent protein (EGFP) in a subset of interneurons containing somatostatin, we show that Schaffer collateral synapses onto the EGFP-expressing somatostatin interneurons in CA1 have very large short-term facilitation, even larger facilitation than onto pyramidal cells, in contrast to the majority of interneurons that have little or no facilitation. Using a combination of electrophysiological recordings and mathematical modeling, we show that the large short-term facilitation is caused both by a very low initial release probability and by synaptic activation of presynaptic kainate receptors that increase release probability on subsequent stimuli. Thus, we have discovered a novel mechanism for target cell-specific short-term plasticity at Schaffer collateral synapses in which the activation of presynaptic kainate receptors by synaptically released glutamate contributes to large short-term facilitation, enabling selective enhancement of the inputs to a subset of interneurons. ER -