McGuiness et al, "Presynaptic NMDARs in the Hippocampus Facilitate Transmitter Release at Theta Frequency", Neuron 68, 1109–1127, December 22, 2010
I go to two journal clubs, one nice the other nasty. Today was the nasty one, where we looked at the above article. It was the usual pattern - a paper that I thought was quite impressive, turned out to have feet of clay when subjected to the withering scrutiny of the assembled critical intelligences.
In this study, they used Ca-sensitive dyes to image Ca-transients in presynaptic boutons of the CA3-CA1 pathway, in response to action potentials. They claim that the distribution of Ca-transient amplitudes is bimodal. Various drug manipulations, including the use of norketamine to block (internally) only presynaptic NMDARs, demonstrate that the less frequent, large transients are dependent on presynaptic NMDARs. Trouble is, after fig 1 they don’t show us the data – just their opaque Bayesian analysis. And what is worse, they use the same control data in most of their figures.