Podcast
Questions and Answers
The Tet-Off system primarily utilizes a doxycycline-sensitive transcriptional ______
The Tet-Off system primarily utilizes a doxycycline-sensitive transcriptional ______
activator
In the absence of Dox, the tTa binds to the ______ to enable transgene expression.
In the absence of Dox, the tTa binds to the ______ to enable transgene expression.
TRE
The tetracycline-controlled transactivator protein is referred to as ______.
The tetracycline-controlled transactivator protein is referred to as ______.
tTa
Removing Dox from the diet allows for the expression of the ______ at a specified timepoint.
Removing Dox from the diet allows for the expression of the ______ at a specified timepoint.
The ______ acetyltransferase (ChAT) promoter can be used to express a transgene in cholinergic neurons.
The ______ acetyltransferase (ChAT) promoter can be used to express a transgene in cholinergic neurons.
Administration of Dox after training will ______ the expression of the transgene.
Administration of Dox after training will ______ the expression of the transgene.
Glutamate acid ______ 67 (GAD67) is a promoter that can selectively target GABAergic neurons.
Glutamate acid ______ 67 (GAD67) is a promoter that can selectively target GABAergic neurons.
Mayford and colleagues conditionally used the Tet-Off system to express a mutant ______ transgene in adult mice.
Mayford and colleagues conditionally used the Tet-Off system to express a mutant ______ transgene in adult mice.
To target ______ neurons, a researcher can use the dopamine receptor D1a (Drd1a) promoter.
To target ______ neurons, a researcher can use the dopamine receptor D1a (Drd1a) promoter.
Placing the animal back on Dox suppresses the expression of the mutant ______ transgene.
Placing the animal back on Dox suppresses the expression of the mutant ______ transgene.
The gonadotropin-releasing hormone (______GnRH) promoter specifically targets the hypothalamus.
The gonadotropin-releasing hormone (______GnRH) promoter specifically targets the hypothalamus.
The impairment in LTP and spatial memory was determined to be ______, as it could be reversed by reinstating Dox.
The impairment in LTP and spatial memory was determined to be ______, as it could be reversed by reinstating Dox.
Gene mutations can be targeted to astrocytes using the glial fibrillary ______ protein (GFAP) promoter.
Gene mutations can be targeted to astrocytes using the glial fibrillary ______ protein (GFAP) promoter.
There are limits to the administration protocol, including differences in the time window of ______ and differences in recombination efficiency.
There are limits to the administration protocol, including differences in the time window of ______ and differences in recombination efficiency.
If tight spatial control over genetic manipulation is not necessary, a standard, non-inducible manipulation may be more ______.
If tight spatial control over genetic manipulation is not necessary, a standard, non-inducible manipulation may be more ______.
CaMKIIα starts to express around postnatal day ______.
CaMKIIα starts to express around postnatal day ______.
Conditional genetic systems have allowed researchers to restrict genetic manipulations in both time and ______.
Conditional genetic systems have allowed researchers to restrict genetic manipulations in both time and ______.
EMX1 mRNA is detected at ______ in mouse brains.
EMX1 mRNA is detected at ______ in mouse brains.
Recent advances have made it possible for neuronal activity and genetic information to be altered within specific ______ during defined time windows.
Recent advances have made it possible for neuronal activity and genetic information to be altered within specific ______ during defined time windows.
In many cases, there may be more than one ______ which can achieve the desired transgene expression profile.
In many cases, there may be more than one ______ which can achieve the desired transgene expression profile.
These technical improvements have allowed researchers to identify the roles of discrete neuronal ______ in specific phases of behavior.
These technical improvements have allowed researchers to identify the roles of discrete neuronal ______ in specific phases of behavior.
It is now possible to 'tag' a population of neurons active during a discrete time ______ and manipulate their activity later.
It is now possible to 'tag' a population of neurons active during a discrete time ______ and manipulate their activity later.
This unprecedented ______ has changed how researchers approach the role of genetics in behavior.
This unprecedented ______ has changed how researchers approach the role of genetics in behavior.
Research has fundamentally changed the understanding of the function of active cells in memory ______.
Research has fundamentally changed the understanding of the function of active cells in memory ______.
The TetTag and CreERT2 systems have been modified to express different regulators of neural activity allowing bidirectional control over tagged ______.
The TetTag and CreERT2 systems have been modified to express different regulators of neural activity allowing bidirectional control over tagged ______.
ArcCreERT2 mice were bred with mice expressing a STOP-floxed inhibitory optogenetic receptor called ______.
ArcCreERT2 mice were bred with mice expressing a STOP-floxed inhibitory optogenetic receptor called ______.
Injecting the mice with 4-OHT before training allowed expression of Arch selectively in cells active during context fear ______.
Injecting the mice with 4-OHT before training allowed expression of Arch selectively in cells active during context fear ______.
Optogenetic inhibition of tagged cells was critical for successful memory ______.
Optogenetic inhibition of tagged cells was critical for successful memory ______.
The excitatory optogenetic receptor ______ allows tagged neurons to be stimulated at a later timepoint.
The excitatory optogenetic receptor ______ allows tagged neurons to be stimulated at a later timepoint.
DREADDs stands for Designer Receptors Exclusively Activated by ______.
DREADDs stands for Designer Receptors Exclusively Activated by ______.
Researchers have used these methods to interrogate the memory ______.
Researchers have used these methods to interrogate the memory ______.
These techniques have even been used to create a ______ memory during experiments.
These techniques have even been used to create a ______ memory during experiments.
The DIO/FLEx system allows the DREADD virus to remain dormant until ______ application.
The DIO/FLEx system allows the DREADD virus to remain dormant until ______ application.
Only cells projecting from region A to ______ will receive both viruses.
Only cells projecting from region A to ______ will receive both viruses.
Exposure to a systemic injection of ______ will selectively activate or repress pathway-specific cells.
Exposure to a systemic injection of ______ will selectively activate or repress pathway-specific cells.
The combination of IEG-based promoters, Cre recombination, and methods of modulating ______ activity has advanced neural research.
The combination of IEG-based promoters, Cre recombination, and methods of modulating ______ activity has advanced neural research.
DREADDs can be combined with a virus encoding the gene in a flipped ______/FLEx configuration.
DREADDs can be combined with a virus encoding the gene in a flipped ______/FLEx configuration.
A retrograde virus (e.g. CAV-2) expressing ______ can be injected into the target region.
A retrograde virus (e.g. CAV-2) expressing ______ can be injected into the target region.
Manipulating the activity of cells at specific timepoints in distinct ______ has become more feasible.
Manipulating the activity of cells at specific timepoints in distinct ______ has become more feasible.
Understanding the roles of individual ______ within neural circuits has been challenging until recently.
Understanding the roles of individual ______ within neural circuits has been challenging until recently.
Study Notes
Gene Targeting Promoters
- Choline acetyltransferase (ChAT) promoter targets cholinergic neurons for transgene expression.
- Glutamate decarboxylase 67 (GAD67) and glutamate receptor 1 (GluR1) promoters selectively target GABAergic neurons.
- Dopaminergic neurons can be targeted using dopamine receptor D1a (Drd1a) or preprotachykinin 1 (Tac1) promoters.
- Gonadotropin-releasing hormone (mGnRH) promoter allows specific targeting of the hypothalamus.
- Glial fibrillary acidic protein (GFAP) promoter confines gene expression, such as LacZ, to astrocytes in the central nervous system.
Promoter Selection and Timing
- The choice of promoter depends on experimental context, including gene expression patterns and timing.
- Examples of timing include:
- CaMKIIα expression begins around postnatal day 1 (P1).
- EMX1 mRNA detected at embryonic day 9.5 (E9.5).
- Syn1 expression in rats starts at embryonic day 13 (E13).
- ChAT expression in mouse neurons begins at embryonic day 11 (E11).
- GAD67 expression starts at embryonic day 17 (E17) in rats.
- Multiple available promoters may require pilot studies to determine optimal transgene expression.
Tet-Off and Tet-On Systems
- These systems use a doxycycline-sensitive transcriptional activator paired with a tetracycline-responsive promoter element (TRE).
- In the Tet-Off system, transgene expression occurs only in the absence of doxycycline (Dox), allowing for experimental control over gene activation.
- Early research demonstrated that removal of Dox can lead to memory impairments, reversible by re-administering Dox.
Advances in Genetic Manipulation
- Conditional genetic systems enable precise temporal and spatial control over genetic manipulations in neuronal circuits.
- Recent techniques allow tagging specific neuronal populations active during certain behaviors for later manipulation.
- Example: Researchers expressed the inhibitory optogenetic receptor Arch in neurons active during fear memory acquisition to study memory retrieval.
Functional Studies Using Tagging Systems
- ArcCreERT2 mice combined with optogenetic receptors allow for manipulating both inhibition and stimulation of tagged neurons.
- DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) enable chemogenetic control of targeted neurons.
- Techniques have explored the memory "engram," facilitating the forceful recall of memories and altering the original memory encoding.
Targeting Specific Cell Populations
- DREADDs can target specific populations via Cre recombination linked to promoter specificity, either through transgenic lines or viral methods.
- DIO/FLEx system permits gene activation only in cells expressing Cre, achieving pathway-specific control.
- Retrograde and anterograde viral strategies facilitate selective DREADD expression in neuronal pathways.
The CRISPR Revolution
- Integration of immediate early gene (IEG) promoters, Cre recombination, and neural activity modulation techniques enables precise control over neural circuits.
- The recent advancements in gene manipulation have improved understanding of individual gene roles within complex neural networks.
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Description
Test your knowledge on the use of specific promoters to express transgenes in various types of neurons. This quiz covers key concepts related to cholinergic, GABAergic, and dopaminergic neurons and their respective genetic markers. Dive into the fascinating world of neurotransmitter research!
