Two-photon uncaging comes of age?

In November & December 2006 two more groups reported 2P uncaging of MNI-glutamate. This makes 6 who have reported such. The work of Magee, Sabatini and Svoboda have been mentioned here already. Now Yuste (doi:10.1073/pnas.0609225103 & doi:10.1073/pnas.0608755103 ) and Huganir (doi:10.1073/pnas.0608492103 ) have used the approach originally published by us with Kasai in Nature Neuroscience in 2001.

Huganir shows lovely AMPA-R currents from CA1 that mimic a mEPSC recorded in the same preparation (B above). We called these 2pEPSC in 2001. Kasai reminded me recently that he and I discussed at length what to call these. I suggested "uEPSC"-wanting one simple lower case letter to replace the "m" of the mini in mEPSC. But Kasai wisely said this did not emphasize the distinctiveness of the technique, so he came up with "2pEPSC". Huganir uses "2P-EPSC", Svoboda "uEPSC", Sabatini "2PLU", Magee "gluEPSC"! [I would now say that "uEPSC" ought to be reserved for unitary-EPSCs.]

There are some slight differences reported in these papers to those previously: Huganir's lateral resolution (C, above) is somewhat worse than Magee's (e, left x-resolution, right z-resolution). Yuste reports that they see no correlation between spine head volume and AMPA-R density (probably due to resolution issues), but Haganir (not shown here) and Magee do (f above).

In spite of these quibbles, with the publication of 3 more elegant papers using MNI-Glu by two groups, I think we can say that 2-photon uncaging has come of age.