This just in from Clay:

 

Three reviews:

Luo et al. 2008 (very long, so concentrate only on 643 - 649)

Smith 2007

Briggman & Denk 2006

 

 

Original papers, only for those who are interested:

Wickersham et al. 2007

Michaeva et al. 2007

Denk & Horstman 2004