Optogenetics Flashcards
(20 cards)
What channels are needed for optogenetics?
Light sensitive channels
Where are photoreceptors naturally found?
Algae (not mammals)
What is optogenetics?
Use of light to control tissue (neurons) that contains light sensitive receptors
What is channelrhodopsin?
An ion channel that opens in response to blue light
How are opsins introduced in mammalian tissues?
Viral vectors (introduce gene into the genome of host cell)
What is the purpose of mCherry in optogenetics?
Reporter gene to know which cells have the opsin
What is the purpose of different opsins for optogenetics?
Different lights (stimuli), receptors and channels, and effects in neurons (excitatory or inhibitory)
What is the strength of optogenetics?
Allow for complete control of the neuron
How come optogenetics does not affect neighboring neurons?
Only the neurons with the opsin (not native) can react to light
How is the light sent to the brain for optogenetics?
Fiber optic cables
How is the selectivity increased in optogenetics?
Using Cre-Lox
How does Cre-Lox work?
Only cells with Cre recombinase can get rid of the stop cassette within loxP sites, allowing for gene transcription
What is a stop cassette?
Stops the expression of downstream genes
What is Cre recombinase?
An enzyme that gets rid of DNA sequences between two loxP sites
How is Cre-Lox used with optogenetics?
Only cells that have Cre recombinase can express the opsin, thus giving more control into what neurons can be affected
What is meant by frequency-dependency (in terms of optogenetics)?
The frequency of the signal is important for the neuron signaling
What are some controls needed for an optogenetic study (such as the wakefulness study)?
Not having the channelrhodopsin, using a different frequency, having the reporter gene, using a different light, etc.
How could optogenetics be used to study Parkinson’s?
Study what are the critical neurons for clinical intervention
What is the significance of high frequency stimulation and low frequency stimulation (in terms of optogenetics)?
Changes the firing patterns in the neurons, which changes the behavior
What happens if the action potential is controlled?
The behavior is controlled
