What resolves this contention: Both invoke presynaptic NMDARs at cortical t-LTD…

What resolves this contention: Both invoke presynaptic NMDARs at cortical t-LTD, but disagree on whether the receptor signals through Ca-flux (canonical ionotropic) or non-ionotropically — implying different mechanistic categories for ostensibly the same form of cortical t-LTD. / We conclude that neocortical L5 PC→PC tLTD relies on non-ionotropic preNMDAR signaling via JNK2/STX1a. / Moreover, whereas t-LTD at vertical inputs requires presynaptic NMDA receptors and is expressed presynaptically, using paired recordings we find that t-LTD at horizontal inputs requires postsynaptic NMDA receptors and is expressed postsynaptically.