CaMK-2 activation is synapse specific during LTP.

Ryohei Yasuda and co-workers paper combing 2-photon uncaging of MNI-glu and FRET-FLIP imaging of CaMK-2 is finally out in Nature this week (those who read Ryohei's Japanese weblog know this paper was accepted a while ago). I had briefly mentioned this technical tour-de-force recently in discussing Sabatini latest Neuron paper using the "PiSing technique" originally developed by Matsuzaki and Kasai. Yasuda's group showed some of their data at SfN in DC last November. Like Kasai, Sabatini and Svoboda, they report synapse-specific induction of LTP using 2P uncaging of MNI-glu induces large and permanent volume changes of targeted spine heads, whilst the near by spines are essentially unaffected. This is due to the exquisite resolution of 2PP (less than 2 microns). In this Nature article Yasuda's lab use FRET-FLIM imaging to reveal that the kinase is only active for a brief period, even though it effects are long lasting. Given Kasai's work, this does not seem too surprising to me. But what do I know?

Seok-Jin R. Lee, Yasmin Escobedo-Lozoya, Erzsebet M. Szatmari & Ryohei Yasuda.
Activation of CaMKII in single dendritic spines during long-term potentiation. Nature (2009) 458:299-304.

A small gripe: the supplemental movies do not play on an Apple computer! This is not unique, would it kill journals to check this before they publish them? About 25% of academics use a Macintosh.

Matsuzaki, M., Honkura, N., Ellis-Davies, G. C. & Kasai, H. Structural basis of long-term potentiation in single dendritic spines. Nature (2004) 429:761-6.