TY  - JOUR
A1  - Schultheis, Christian
A1  - Liewald, Jana Fiona
A1  - Bamberg, Ernst
A1  - Nagel, Georg
A1  - Gottschalk, Alexander
T1  - Optogenetic Long-Term Manipulation of Behavior and Animal Development
JF  - PLoS ONE
N2  - Channelrhodopsin-2 (ChR2) is widely used for rapid photodepolarization of neurons, yet, as it requires high-intensity blue light for activation, it is not suited for long-term in vivo applications, e. g. for manipulations of behavior, or photoactivation of neurons during development. We used "slow" ChR2 variants with mutations in the C128 residue, that exhibit delayed off-kinetics and increased light sensitivity in Caenorhabditis elegans. Following a 1 s light pulse, we could photodepolarize neurons and muscles for minutes (and with repeated brief stimulation, up to days) with low-intensity light. Photoactivation of ChR2(C128S) in command interneurons elicited long-lasting alterations in locomotion. Finally, we could optically induce profound changes in animal development: Long-term photoactivation of ASJ neurons, which regulate larval growth, bypassed the constitutive entry into the "dauer" larval state in daf-11 mutants. These lack a guanylyl cyclase, which possibly renders ASJ neurons hyperpolarized. Furthermore, photostimulated ASJ neurons could acutely trigger dauer-exit. Thus, slow ChR2s can be employed to long-term photoactivate behavior and to trigger alternative animal development.
KW  - Nematode Caenorhabditis-elegans
KW  - C-elegans
KW  - Millisecond-timescale
KW  - Chemosensory neurons
KW  - Glutamate-receptor
KW  - Larval development
KW  - Optical control
KW  - Dauer formation
KW  - Channelrhodopsin-2
KW  - Pheromone
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-141250
VL  - 6
IS  - 4
ER  - 
TY  - JOUR
A1  - Gao, Shiqiang
A1  - Nagpal, Jatin
A1  - Schneider, Martin W.
A1  - Kozjak-Pavlovic, Vera
A1  - Nagel, Georg
A1  - Gottschalk, Alexander
T1  - Optogenetic manipulation of cGMP in cells and animals by the tightly light-regulated guanylyl-cyclase opsin CyclOp
JF  - Nature Communications
N2  - Cyclic GMP (cGMP) signalling regulates multiple biological functions through activation of protein kinase G and cyclic nucleotide-gated (CNG) channels. In sensory neurons, cGMP permits signal modulation, amplification and encoding, before depolarization. Here we implement a guanylyl cyclase rhodopsin from Blastocladiella emersonii as a new optogenetic tool (BeCyclOp), enabling rapid light-triggered cGMP increase in heterologous cells (Xenopus oocytes, HEK293T cells) and in Caenorhabditis elegans. Among five different fungal CyclOps, exhibiting unusual eight transmembrane topologies and cytosolic N-termini, BeCyclOp is the superior optogenetic tool (light/dark activity ratio: 5,000; no cAMP production; turnover (20 °C) ~17 cGMPs\(^{-1}\)). Via co-expressed CNG channels (OLF in oocytes, TAX-2/4 in C. elegans muscle), BeCyclOp photoactivation induces a rapid conductance increase and depolarization at very low light intensities. In O\(_2\)/CO\(_2\) sensory neurons of C. elegans, BeCyclOp activation evokes behavioural responses consistent with their normal sensory function. BeCyclOp therefore enables precise and rapid optogenetic manipulation of cGMP levels in cells and animals.
KW  - carbon dioxide avoidance
KW  - III adenylyl cyclases
KW  - rhodopsin
KW  - in vivo
KW  - optical control
KW  - Halobacterium halobium
KW  - C. elegans
KW  - cellular camp
KW  - Caenorhabditis elegans
KW  - nucleotide-gated channel
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148197
VL  - 6
IS  - 8046
ER  -