Winning the Prize(s).



The SGP 2010 annual meeting is over, several people told me they had a great time. There were many really wonderful presentations. But it could be argued that there were two areas that emerged of fundamental importance. Thus, one of the talking points was who might win what when? Here I lay out the history of these two areas: genetically encoded optical methods (sensing & actuation) and super resolution imaging.

Geneto-optics.

Sensing.

C19th: Golgi and Cajal.

 Talk about fundamental.

As chemists and physicists develop lasers and optical methods to study chemical reactions, these tools are applied to biology in 1970s (e.g. intrinsic imaging, voltage sensitive dyes and pH indicators). For neuroscience, voltage sensitive dyes have obvious appeal, but in spite of decades of work and 1000s of dyes made, they still do not work very well. For this reason, the calcium dyes made by Roger Tsien have much more impact.

Calcium dyes before and after Roger Tsien. The importance of calcium
 selective fluorescence.

Before Roger, absorption dyes such antipyrillazo-3, etc
 are used.
quin2 1980, fura-2 1985, fluo-4 rhod-2 1988 revolutionize calcium imaging.

The rise of GFP.


1982 Prasher sequences but stated it was not fluorescent without another protein.
1984 Chalfie C elegans and Tsien eGFP.
 Prasher is a co-author but misses the Nobel.
1987-the Big Year for sensors.

Miesenbock genetically encoded indicator pH.

Tsien cameleon for calcium

Persechini for CaM.

Isacoff SPARC for voltage.



2002 synapto-pHluorins in flies first genetically encoded analysis of neural
circuits in vivo, Miesenbock.



Actuation.



1971 Fork fires lasers at neurons to generate action potentials.

1978 caged ATP
.
1982 Grinvald lasers fired at neurons with a dye in them.

1993 caged Glu on neurons in slices, Katz
.
1994 two photon uncaging acetyl choline analog, Denk.

1999 and 2001 Ellis-Davies and Kasai, first diffraction limited (2P) uncaging.


I presented the first example of diffraction-limited uncaging of glutamate as a speaker at the SGP annual conference in the Summer of 1999. Also the first example of 2P uncaging of calcium in living cells with normal magnesium concentrations. I am told that Knox Chandler, who was in the audience, commented: “So they’ve done it!”
2002 chARGed, Miesenbock uses the rhodopsin chromophore in the first entirely genetically encoded actuation.

2003 genetically targeted ionotropic triggers: alien receptors plus caged
 compounds, Miesenbock.


2005 Uncaging ATP in headless fruit fly with alien P2X2 receptors makes them fly! Miesenbock. Published 7 April 2005. Jan Leno makes a joke on the Tonight Show about this work.

Light-gated ion channels and pumps for neuronal actuation.



1981 Bacteriodopsin cloned 1981.
1990 Halorhodopsin cloned 1990.
2001 ChR1 cloned Nagel.

2002 ChR2 cloned
 Nagel.
2005 ChR2 in hippocampal neurons (Deisseroth, submitted 12 May 2005, published, 14 August online) and C elegans (Gottschalk, sumitted 16 August, published 19 December) 
both 2005.

In these 4 papers Ernst Bamberg was a co-author, but generously did not take communicating authorship.
2006 ChR2 in mouse visual system Pan & coworkers, Neuron.

2007 ChR2 to control mouse behavior. Deisseroth.
2009 ChR2 to dissect neural circuits in mouse, Deisseroth Parkinson paper in Science.





Super resolution imaging: Abbe and the "diffraction barrier".



Near field imaging

.

1928 E.H. Synge proposes the idea (in a published letter to Einstein).
1993 40 nm resolution of single molecules. Betzig

.
1984 Near-field microscopy is realized by Pohl, Denk, Lanz of IBM
Zurich as well as A. Lewis et al.

Far field optical fluorescence imaging beyond the diffraction barrier.




1992 4Pi, Hell and Seltzer.


1994 STED, Hell.


1995 I5M, Gustafsson and Sadat.

Stefan Hell has pointed out that 4Pi and I5M move the diffraction barrier, but do not remove it, thus these methods remain "diffraction limited". In contrast, STED was the first far field method that destroyed Abbe's diffraction limit.



1995 GSD, Hell.



Structured illumination.
2003 Heintzmann
2005 Gustafsson.

2006.
PALM, Betzig. Submitted 13 march, accepted 2 aug, online 10 aug
 2006.
STORM Zhuang. Submitted 7 jul, accepted 31jul, online 9 aug, paper oct 2006

FPALM Samuel Hess. Submitted 12 june, accepted 28 aug, appeared dec
 2006.


Zhuang’s paper took only 3 weeks to be accepted!