AAV GRAB sensors

The complex function in the brain is inseparable from the efficient and specific information exchange and integration between neurons. Neurotransmitters (such as acetylcholine, dopamine, and neuropeptides ) are a key biological small molecules and participate in the process of information transmission mediated by chemical synapses between neurons, and are involved in a variety of physiological functions including development, information perception, motor regulation and higher-level cognitive behavior in the brain, and the devastating diseases will be caused once the malfunction of neurotransmitter, such as Parkinson's disease, Alzheimer's disease, addiction and epilepsy. Therefore, the study of neurotransmitter is essential for understanding the mechanism of brain function.

Sun, F., et al. Cell 2018

Li Yulong’s lab from Peking University develops cutting edge research tools, namely advanced imaging probes (GRAB sensors), including published dopamine (2018, Cell), acetylcholine (2018, Nature Biotechnology), and norepinephrine (2019, Neuron), to untangle the complexity of nervous system in space and in time, and helps to understand the changes of neurotransmitters in specific diseases, thus providing a new path for future precision medicine and new drug development.

The GRAB sensors could be expressed in specific cell-types and are able to detect dynamics of extracellular neurotransmitters in cultured cell, brain slice and living animal (e.g. fly, zebrafish, mice, rat, monkey etc.) by transfection, virus injection or construction of transgenic animals. For the aspect of instruments, GRAB sensors could perform well in epifluorescence microscopy, confocal microscopy, 2P microscopy and fiber photometry recording.

The Yulong Li Lab has deposited sensor plasmids at BrainVTA for distribution to the research community, and all GRAB
sensors (including the lastest ACh, DA, NE, 5-HT, Ado, ATP, VIP, CCK and eCB sensors) with AAV are available. To view the probe list, please click the Neurotransmitter sensors or contact [email protected].

Note: please contact the Li Lab ([email protected]) before ordering unpublished sensors.

Features of published sensors

Name	Neurotransmitters	Version	Color	Backbones(From human)	Affinity	Signal Response Amplitude	Dynamics	Downstream Signal Coupling	Reference
Ach2.0	Acetylcholine	First generation	Green	M3 receptor	EC50~1uM	ΔF/F0~90%	τon~200ms, τoff~800ms	Weak	[1]
Ach3.0	Acetylcholine	Second generation	Green	M3 receptor	EC50~2uM	ΔF/F0~280%	τon~112ms, τoff~580ms	Hardly	[2]
Ach3.0-mut	Acetylcholine	Control of Second generation	Green	M3 receptor	EC50~0uM （W200A mutation）	ΔF/F0~1.8%	/	/	[2]
DA1m	Dopamine	First generation	Green	D2 receptor	EC50~130nM Medium affinity	ΔF/F0~90%	τon~60ms, τoff~700ms	Hardly	[3]
DA1h	Dopamine	First generation	Green	D2 receptor	EC50~10nM High affinity	ΔF/F0~90%	τon~140ms, τoff~2500ms	Hardly	[3]
DAmut(1st)	Dopamine	Control of First generation	Green	D2 receptor	EC50~0uM C118A and S193N mutation	No effect	/	/	[3]
DA2m(DA4.4)	Dopamine	Second generation	Green	D2 receptor	EC50~90nM Medium affinity	ΔF/F0~340%	τon~40ms, τoff~1300ms	Little	[4]
DA2h(DA4.3)	Dopamine	Second generation	Green	D2 receptor	EC50~7nM High affinity	ΔF/F0~280%	τon~50ms, τoff~7300ms	Little	[4]
DAmut(2nd)	Dopamine	Control of Second generation	Green	D2 receptor	EC50~0uM C118^3.36A and S193^5.42N mutation	No effect	/	/	[4]
rDA1m (rDA2.5m)	Dopamine	/	Red	D2 receptor	EC50~95nM Medium affinity	ΔF/F0~150%	τon~80ms, τoff~770ms	Little	[4]
rDA1h (rDA2.5h)	Dopamine	/	Red	D2 receptor	EC50~4nM Medium affinity	ΔF/F0~100%	τon~60ms, τoff~2150ms	Little	[4]
rDAmut (rDA2.5mut)	Dopamine	Control	Red	D2 receptor	EC50~0uM C118^3.36A and S193^5.42N mutation	No effect	/	/	[4]
NE1m(NE2.1)	Norepinephrine	/	Green	a2A receptor	EC50~930nM Medium affinity	ΔF/F0~230%	τon ~70ms, τoff~ 750ms	Uncoupled	[5]
NE1h(NE2.2)	Norepinephrine	/	Green	a2A receptor	EC50~83nM High affinity	ΔF/F0~130%	τon ~30ms, τoff~ 2000ms	Uncoupled	[5]
NEmut	Norepinephrine	/	Green	a2A receptor	EC50~0uM S5.46A mutation	No effect	/	/	[5]
Ado1.0	Adenosine	Control	Green	a2A receptor	EC50~60nM	ΔF/F0~130%	τon~36ms, τoff~1890ms	Hardly	[6]
Ado1.0mut	Adenosine		Green	a2A receptor	EC50~0uM F168A mutation	No effect	/	/	[6]
5-HT1.0	Serotonin	Control	Green	5-HT2C receptor	EC50~22nM	ΔF/F0~250%	τon~0.2s, τoff~3.1s	Uncoupled	[7]
5-HTmut	Serotonin	/	Green	5-HT2C receptor	EC50~0uM D134^3.32Q mutation	No effect	/	/	[7]

FAQ:
1. What do the abbreviation h/m/l/mut mean, and what about the number?
h/m/l is the abbreviation of high/median/low, which indicates the sensors' apparent affinity towards transmitter. Most of the GRAB sensors have transmitter-insensitive mutant for comparison with GRAB sensors to check signal specificity. The number represents the version of sensor, the higher version, the better performance.

2. How to use GRAB sensors?
GRAB sensors are genetically encoded sensors for neurotransmitters, similar to other genetically encoded sensors (e.g. GCaMP). They could be expressed in specific cell-types and are able to detect dynamics of extracellular neurotransmitters in cultured cell, brain slice and living animal (e.g. fly, zebrafish, mice, rat, monkey etc.). For the aspect of instruments, GRAB sensors could perform well in epifluorescence microscopy, confocal microscopy, 2P microscopy and fiber photometry recording.

3. Can the sensors be expressed in vivo for a long-term period?
Yes. We can record good signals from GRAB sensor after expression for 3 to 6 months in mice brain by AAV infection.

4. Can GRAB sensors detect excitability of neurons?
No. The change of fluorescent intensity only indicates the dynamics of corresponding neurotransmitter, which has no direct correlation with excitability of neurons. Other approach is needed for detection of neuron excitability.

Reference
1. Jing, M., et al. (2018). "A genetically encoded fluorescent acetylcholine indicator for in vitro and in vivo studies." Nat Biotechnol 36(8): 726-737.
2. Jing, M., et al. (2020). "An optimized acetylcholine sensor for monitoring in vivo cholinergic activity." Nat Methods 17(11): 1139-1146.
3. Sun, F., et al. (2018). "A Genetically Encoded Fluorescent Sensor Enables Rapid and Specific Detection of Dopamine in Flies, Fish, and Mice." Cell 174(2): 481-496 e419.
4. Sun, F., et al. (2020). "Next-generation GRAB sensors for monitoring dopaminergic activity in vivo." Nat Methods 17(11): 1156-1166.
5. Feng, J., et al. (2019). "A Genetically Encoded Fluorescent Sensor for Rapid and Specific In Vivo Detection of Norepinephrine." Neuron 102(4): 745-761 e748.
6. Peng, W., et al. (2020). "Regulation of sleep homeostasis mediator adenosine by basal forebrain glutamatergic neurons." Science 369(6508).
7. Wan, J., et al. (2021). "A genetically encoded sensor for measuring serotonin dynamics." Nat Neurosci.

Don’t See What You’re Looking For?
Perhaps, you don't see What You’re Looking For ? Simply , just click the Custom-Made AAVs Button and submit your needs to us.

Return to top