Channelrhodopsin Chr2
Channelrhodopsin Chr2 - Related Videos
08:39
Whole-cell Patch-clamp Recordings for Electrophysiological Determination of Ion Selectivity in Channelrhodopsins
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Cited by 26 •
2017
This article describes how the ion selectivity of channelrhodopsin is determined with electrophysiological whole-cell patch-clamp recordings using HEK293 cells. Here, the experimental procedure for investigating chloride selectivity of an anion-selective channelrhodopsin is demonstrated. However, the procedure is transferable to other channelrhodopsins of distinct selectivity.
07:04
Long-range Channelrhodopsin-assisted Circuit Mapping of Inferior Colliculus Neurons with Blue and Red-shifted Channelrhodopsins
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Cited by 4 •
2020
Channelrhodopsin-assisted circuit mapping (CRACM) is a precision technique for functional mapping of long-range neuronal projections between anatomically and/or genetically identified groups of neurons. Here, we describe how to utilize CRACM to map auditory brainstem connections, including the use of a red-shifted opsin, ChrimsonR.
08:31
FM Dye Cycling at the Synapse: Comparing High Potassium Depolarization, Electrical and Channelrhodopsin Stimulation
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Cited by 7 •
2018
Synaptic vesicle (SV) cycling is the core mechanism of intercellular communication at neuronal synapses. FM dye uptake and release are the primary means of quantitatively assaying SV endo- and exocytosis. Here, we compare all the stimulation methods to drive FM1-43 cycling at the Drosophila neuromuscular junction (NMJ) model synapse.
03:01
Drosophila Optogenetics: A Method to Manipulate Neuronal Circuits
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2023
Optogenetics enables the use of light to manipulate neurons that are genetically engineered to express specific opsins–light-sensitive proteins whose light activation triggers a change in the state of the neuron. Here we describe an optogenetic approach in Drosophila using the opsin Channelrhodopsin2. The example protocol features an optogenetics assay set to study the neuronal circuitry behind the fly's escape behavior.
04:18
Visualization and Mapping of Neuronal Pathways in an Amygdala Brain Slice
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2025
This video demonstrates a procedure for analyzing synaptic connectivity between medial prefrontal cortex (mPFC) and amygdala neurons using acute amygdala brain slices from mice. The mPFC neurons in these mice express channelrhodopsin fused to a fluorescent protein. The channelrhodopsins facilitate ion influx and action potential generation in the mPFC neurons upon light activation. Consequently, mPFC neurons release neurotransmitters that bind to postsynaptic amygdala neurons, triggering...
FAQs
Blue light causes Chr2 to change conformation, opening its membrane pore. Sodium and calcium ions can then enter the neuron, shifting the membrane potential toward depolarization. If the voltage change reaches the conditions needed for neuronal firing, the cell can generate action potentials. This light-dependent sequence links illumination to rapid changes in neural activity.
The inward movement of sodium and calcium provides the ionic basis for depolarization after the channel opens. Depolarization brings the membrane potential closer to the level required for action-potential generation, allowing researchers to influence whether targeted neurons become active. Thus, the channel's ion permeability connects a controlled optical stimulus with measurable electrical responses in neural cells.
Chr2 supports control that is both rapid in timing and restricted to genetically targeted neurons. This combination helps researchers distinguish the effects of a selected neural population from activity produced by less specific stimulation. Electrical stimulation remains a complementary approach, while Chr2-based activation can help test which cells contribute to a circuit response or behavior.
Researchers first introduce Chr2 into a selected neural population so that those cells become responsive to blue light. They then deliver illumination with an implanted or external light source and observe the resulting neural or behavioral effects. The workflow links cell selection, optical activation, and outcome measurement, enabling experiments on connections, circuit functions, or behavior.
Activating the targeted cells allows researchers to examine how their activity influences connected pathways, broader circuit function, and behavior. Responses observed during illumination can help test whether a neural population participates in a particular process. Depending on the experiment, the measured outcome may relate to sensory processing, motor control, or behavioral responses.
The technique is relevant to studies of sensory processing and motor systems because researchers can activate selected neurons while examining circuit or behavioral consequences. It also supports investigation of neurological disorders and potential therapeutic strategies. By connecting genetically defined cell populations with controlled optical stimulation, experiments can probe normal function as well as disease-related neural mechanisms.