Bi-stable neural state switches

@article{Berndt2009BistableNS,
  title={Bi-stable neural state switches},
  author={Andr{\'e} Berndt and Ofer Yizhar and Lisa A. Gunaydin and Peter Hegemann and Karl Deisseroth},
  journal={Nature Neuroscience},
  year={2009},
  volume={12},
  pages={229-234}
}
Here we describe bi-stable channelrhodopsins that convert a brief pulse of light into a stable step in membrane potential. These molecularly engineered probes nevertheless retain millisecond-scale temporal precision. Photocurrents can be precisely initiated and terminated with different colors of light, but operate at vastly longer time scales than conventional channelrhodopsins as a result of modification at the C128 position that extends the lifetime of the open state. Because of their… Expand
High-efficiency channelrhodopsins for fast neuronal stimulation at low light levels
TLDR
This work screened a large number of ChR2 point mutants and discovered a dramatic increase in photocurrent amplitude after threonine-to-cysteine substitution at position 159, which suggests it may become the standard for light-controlled activation of neurons. Expand
Anion-conducting channelrhodopsins with tuned spectra and modified kinetics engineered for optogenetic manipulation of behavior
TLDR
Two novel eACRs are obtained that convey robust and specific light-dependent inhibition of locomotion and nociception in Drosophila larvae and can be reversibly toggled between open and closed states with brief light pulses of different wavelengths. Expand
Time-resolved infrared spectroscopic techniques as applied to channelrhodopsin
TLDR
This mini-review focuses on time-resolved applications of the infrared technique to study channelrhodopsins and other light triggered proteins and discusses the approaches with respect to their suitability to the investigation of channel rhodopsin and related proteins. Expand
Anion-conducting channelrhodopsins with tuned spectra and modified kinetics engineered for optogenetic manipulation of behavior
TLDR
This work generated 22 variants of blue light-activated engineered anion conducting channelrhodopsins (eACRs) using two conversion strategies applied to 11 CCRs and screened them for membrane expression, photocurrents and anion selectivity, and obtained two novel eACRs, Phobos and Aurora. Expand
Channelrhodopsin-2 is a leaky proton pump
TLDR
It is shown that when ChR2 is expressed in electrofused giant HEK293 cells or reconstituted on planar lipid membranes, it can indeed act as an outwardly driven H+ pump, demonstrating that ChR 2 is bifunctional, and in-line with other microbial rhodopsins, a H+ Pump but with a leak that shows ion channel properties. Expand
Conformational changes of channelrhodopsin-2.
TLDR
A mechanistic model is proposed that links the observed structural changes of ChR2 to the changes in the channel's conductance as indicate by strong differences in the amide I bands. Expand
Artificial anion-conducting channelrhodopsins with tuned spectra, modified kinetics and enhanced light sensitivity
Genetic engineering of natural light-gated ion channels has proven a powerful way to generate optogenetic tools for a wide variety of applications. In recent years, blue light-activated artificialExpand
Enhancing Channelrhodopsins: An Overview.
TLDR
New variants whose efficacy has already been proven in neurophysiological experiments, or variants which are likely to extend the optogenetic toolbox are reviewed. Expand
Ultrafast optogenetic control
TLDR
An engineered opsin gene (ChETA) is designed and validated that addresses all of the limitations of channelrhodopsin-2, profoundly reducing extra spikes, eliminating plateau potentials and allowing temporally stationary, sustained spike trains up to at least 200 Hz. Expand
The branched photocycle of the slow-cycling channelrhodopsin-2 mutant C128T.
TLDR
The photoreactions of a slow-cycling ChR2 mutant (step function rhodopsin), with C128 replaced by threonine and 200-fold extended lifetime of the conducting-state P520 are presented. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 54 REFERENCES
Spectral characteristics of the photocycle of channelrhodopsin-2 and its implication for channel function.
TLDR
It is concluded that the red-shifted spectral species represents the open channel state, and the thermal relaxation of this intermediate, the transition from P(3) to P(4), is coupled to channel closing. Expand
Photoactivation of Channelrhodopsin*
TLDR
The functional expression of VChR cloned from the colonial alga Volvox carteri paves the way toward a broader structure/function analysis of the recently identified class of light-gated ion channels. Expand
Channelrhodopsin-2 and optical control of excitable cells
TLDR
Technological issues relevant to the temporal precision, spatial targeting and physiological implementation of ChR2, in the context of other photostimulation approaches to optical control of excitable cells are explored. Expand
Millisecond-timescale, genetically targeted optical control of neural activity
Temporally precise, noninvasive control of activity in well-defined neuronal populations is a long-sought goal of systems neuroscience. We adapted for this purpose the naturally occurring algalExpand
Allosteric control of an ionotropic glutamate receptor with an optical switch
TLDR
A general approach for manipulating allosteric control using synthetic optical switches is described, exemplified by a ligand-gated ion channel of central importance in neuroscience, the ionotropic glutamate receptor (iGluR), which has potential uses not only in biology but also in bioelectronics and nanotechnology. Expand
Multiple photocycles of channelrhodopsin.
TLDR
ChR1 was reported to respond with a steady-state conductance only but is demonstrated here to have a peak conductance at high light intensities too, and a reaction scheme is developed that describes the photocurrent kinetics at various light conditions. Expand
Red-shifted optogenetic excitation: a tool for fast neural control derived from Volvox carteri
TLDR
A cation-conducting channelrhodopsin (VChR1) from Volvox carteri that can drive spiking at 589 nm, with excitation maximum red-shifted ∼70 nm compared with ChR2 is described, thereby defining a functionally distinct third category of microbial rhodopin proteins. Expand
Light Activation of Channelrhodopsin-2 in Excitable Cells of Caenorhabditis elegans Triggers Rapid Behavioral Responses
TLDR
Channelrhodopsin-2 (ChR2) is employed, a directly light-gated cation channel from the green alga Chlamydomonas reinhardtii, in excitable cells of the nematode Caenorhabditis elegans, to trigger specific behaviors, simply by illumination, in neurons and muscles. Expand
Kinetic evaluation of photosensitivity in genetically engineered neurons expressing green algae light-gated channels
TLDR
The LED light illumination of the photosensitive neurons was enough to evoke action potentials in a pulse-to-pulse manner in an acute slice of hippocampus using blue light-emitting diode (LED) light. Expand
High-speed mapping of synaptic connectivity using photostimulation in Channelrhodopsin-2 transgenic mice
TLDR
It is concluded that ChR2 is a genetically based photostimulation technology that permits analysis of neural circuits with high spatial and temporal resolution in transgenic mammals. Expand
...
1
2
3
4
5
...