Neuronal Tracing Tools
BackgroundProduct DetailsAdvantagesApplications
Background
The mammalian nervous system consists of a seemingly infinitely complex network of specialized synaptic connections
that coordinate the flow of information. In the past few decades, neuroscience research has focused primarily on
molecules, genes, and cells at the microscopic level, or structural/functional networks based on magnetic resonance
imaging and behavior at the macroscopic level. However, the human brain contains approximately 100 billion neurons,
which are connected by approximately 10 quadrillion synapses to form a virtually infinite number of neural circuits
at the mesoscopic level. These circuits are the structural basis for coordinating and executing a wide range of
basic and higher-level brain functions. Elucidating neural circuits is a prerequisite for understanding the
principles of brain function and the pathogenesis of neurological diseases.
Currently, viral tools are widely
used in neural circuit research. They are modified from natural strains of neurotropic viruses, such as herpes
simplex virus (HSV), pseudorabies virus (PRV), rabies virus (RV), vesicular stomatitis virus (VSV), and Sindbis
virus (SINV). In addition, some non-transsynaptic recombinant viral vectors can be used as auxiliary vectors for
exogenous gene expression, such as lentivirus (LV) and adeno-associated virus (AAV), or efficiently label the fine
structure of neurons, such as Semliki Forest virus (SFV), or show upstream projections in local brain areas, such as
AAV2-retro and canine adenovirus type 2 (CAV-2), or efficiently cross the mouse blood-brain barrier (BBB), such as
AAV9-PHP.eB, and retrogradely infect projection neurons after crossing the whole brain BBB, such as AAV9-retro.
Figure 1. Schematics of the anterograde or retrograde transmission of
non-transsynaptic (static) and transsynaptic (trans-multisynaptic or monosynaptic) viral tools. (Liu Q, et
al., 2022)
Product Details
To comprehend the intricate systems of the brain, it is necessary to understand how neurons are connected, to
describe the fine structure of neural circuits, and to recognize their functions. With the advent of viral vector
technology, new methods have been developed to study neuronal connectivity. These methods are less neurotoxic and
better compatible with other neuroscience methods such as electrophysiological recordings. Creative Biogene
developed a series of novel neurotropic virus which can infect neuronal cells, duplicate and transmit along neuronal
tract pathways. These neuronal tracing tools can specifically label cell types and visualize conduction directions
with controllable directionality to enable precise understanding and research of neural circuit networks.
Explore Our Neuronal Tracing Tools
HSV-1 has the properties of neuronal tropism and efficient infection of the central nervous system (CNS),
making it a neuron-specific marker and gene delivery vector.
Vesicular stomatitis virus (VSV) is known for its rapid replication and assembly, high infection
efficiency, and foreign gene expression, and has been shown to be delivered anterogradely between
neurons.
Rabies viruses (RABVs) are ideal viruses for mapping neuronal connectivity due to their transsynaptic
spreading properties, allowing even attenuated forms of RABV to enter axonal transport pathways.
Due to the nature of polysynaptic transmission, Pseudorabies virus (PRV) is an excellent tool for
short-term retrograde tracing of multilevel neural circuits that terminate in the periphery.
Advantages
- Trans-synaptic properties
- Controllable directions: both anterograde and retrograde
- Almost no signal reduction after long distance tracing
- Fast and high-efficiency
- Strong background in neural tracing tool
- Multiple indicators for choice
- Most competitive price
For markers, we have EGFP, dsRed, mCherry, mRFP, tdTomato inserted in the RV, VSV, PRV backbones.
Applications
Recombinant neural viruses have become the most effective and common tools in modern neuroscience research, whether
it is neuronal morphology depiction or neural circuit tracing. Since its first discovery and application, each virus
has been rapidly developed and has made many amazing advances in the past few decades. The following are some
applications of recombinant viruses in neural circuit tracing.
- Targeted gene delivery: Our viral vectors can be designed to express specific genes or shRNAs, allowing
researchers to manipulate gene expression in specific cell types within neural circuits.
- Optogenetics and chemogenetics: Our viral vectors can be used to express optogenetic or chemogenetic tools, such
as channelrhodopsins or designer receptors activated only by designer drugs (DREADDs), to modulate neural
activity with high temporal and spatial precision.
- Circuit tracing: Our viral vectors can be used for anterograde or retrograde tracing of neural circuits,
allowing researchers to map connections between different brain regions.
- Circuit manipulation: Our viral vectors can be used to manipulate neural activity in specific brain regions or
cell types, allowing researchers to explore the causal relationship between neural circuit activity and
behavior.
Our viral vector products are designed to facilitate groundbreaking discoveries in neuroscience research, allowing
researchers to explore the complexity of the brain and generate new insights into the mechanisms underlying neural
function and dysfunction. Creative Biogene can also provide customized neuron tracing viral vectors to customers
around the world. If you are interested in our services and products, please feel free to contact us for more
details.
References:
- Qiu L, Zhang B, Gao Z. Lighting up neural circuits by viral tracing. Neuroscience Bulletin, 2022,
38(11): 1383-1396.
- Saleeba C, et al. A student's guide to neural circuit tracing. Frontiers in neuroscience,
2019, 13: 897.
- Liu Q, et al. Viral tools for neural circuit tracing. Neuroscience bulletin, 2022, 38(12):
1508-1518.
* For research use only. Not intended for any clinical use.