AAV for Neural Circuitry Research

Overview of AAV for Neural Circuitry Research

Introduction of AAV

Adeno-associated viruses (AAVs) are small viruses belong to the genus Dependoparvovirus.With a length of 4.7 kb, the AAV genome is composed of two open reading frames (ORFs), Cap and Rep, which are flanked by inverted terminal repeats (ITRs). Till now, 11 natural serotypes of AAVs have been identified. AAVs are nonenveloped viruses, the gene expression and replication can be activated when the helper viruses are present. Compared to other vectors, the frequency of random integration into the genome of the host cell is much lower. In addition, removing Rep and Cap can further prevent the integrative capacity.

Fig.1 Novel adeno-associated virus (AAV) viral vector-mediated non-trans-synaptic retrograde tracing and trans-blood-brain barrier labeling. ¹

AAV-Based Gene Therapies in Neuroscience

Due to the lack of replication ability and extremely low immunogenicity, AAV has been widely used in neuroscience and gene therapy. To date, there are more than 110 AAV-related gene therapies for clinical trials in the world. The disease indications include but are not limited to:

• Parkinson's disease
• Alzheimer's disease
• Spinal muscular atrophy
• Amyotrophic lateral sclerosis
• Temporal lobe epilepsy
• Charcot-Marie-Tooth disease type 1A

Applications of AAV in Neuroscience

In general, we use the brain stereotactic injection technique to deliver viral vectors to specific brain regions for the expression of specific genes and fluorescence. However, it is not suitable for extensive labeling and gene expression in multiple brain regions because of the limited virus infection efficiency. In this case, the injection of AAV can solve this problem and further improve a variety of research and gene therapy methods.

It is well-known that traditional AAV vectors cannot cross the synapses. In this case, anterograde tracing and retrograde tracing are essential to characterize neuronal networks. Among them, anterograde tracing focuses on labeling known downstream brain regions, while retrograde tracing focuses on upstream brain regions. Compared with fluorescent dyes, viral vectors have the capabilities of retrograde tracking and gene carry. The established rAAV2-retro serotype vector can be absorbed in the axon and retrograde to the nucleus for the expression of fluorescent protein along the cytoskeleton.

Fig.2 Transcriptional targeting of neuronal populations.²

Features of AAV

• High gene delivery ability
• Low immunogenicity
• Capsid protein diversity
• High infection efficiency

Creative Biolabs is one of the well-recognized experts who are professional in applying advanced platforms for a broad range of neurosciences research. We are pleased to use our extensive experience to offer the best service and the most qualified products to satisfy each demand from our customers. If you are interested in our services and products, please do not hesitate to contact us for more detailed information.

Services at Creative Biolabs

Our AAV services aim to provide researchers and scientists with reliable tools and resources to study the complex interconnected networks within the brain and nervous system.

• AAV Production - We offer high-quality AAV vector production services for the delivery of genetic material to neuronal cells. Our AAV vectors are designed to efficiently transduce neurons and enable the targeted manipulation of neural circuits.
• AAV Vector Design - Our team of experts can assist in the design and customization of AAV vectors for specific research applications. We can help optimize vector constructs for optimal transduction efficiency and expression levels in neural tissues.
• AAV Injection Services - We provide in vivo AAV injection services to deliver viral vectors into specific brain regions or tissues of interest. Our experienced team can help researchers accurately target and deliver AAV vectors to specific neural circuits for precise manipulation and study.
• AAV Transduction Efficiency Analysis - We offer a comprehensive analysis of AAV transduction efficiency in neural tissues using advanced imaging and quantification techniques. Researchers can rely on our services to accurately assess transduction levels and optimize experimental protocols.
• AAV Validation Studies - We can conduct validation studies to evaluate the efficacy and specificity of AAV-mediated gene delivery in neural circuits.

Researchers can trust in our expertise and commitment to delivering reliable and innovative solutions for their research needs. We also offer other related services, including but not limited to:

Published Data

The ability of retrograde AAV to infect axons of projection neurons is a powerful tool for anatomical and functional characterization of neural networks. However, few retrograde AAV coats have been shown to be able to enter cortical projection neurons in different species and to be able to manipulate neural function in non-human primates (NHP).

Yefei Chen et al. reported the development of a novel retrograde AAV coat, AAV-DJ8R, which effectively labeled cortical projection neurons after local injection into the striatum of mice and rhesus monkeys. It was found that intra-striatal injection of AAV-DJ8R mediated the expression of opsin in the motor cortex of mice and induced strong behavioral changes. Following viral delivery to the Rhesus monkey chitin nucleus, AAV-DJ8R significantly increased motor cortical neuron firing in response to optogenetic light stimulation.

Fig. 3 Development of a novel retrograde AAV tracer, AAV-DJ8R.³

Applications of AAV in Neural Circuitry Research

• Optogenetics - Our AAV vectors can be used to deliver opsins to specific neurons in a targeted manner, enabling precise control over neural activity within neural circuits.
• Chemogenetics - Our AAV vectors can be used to deliver genes encoding DREADDs to specific brain regions, allowing researchers to remotely control neuronal activity within neural circuits.
• Calcium imaging - Our AAV vectors can be used to deliver genetically encoded calcium indicators to specific neurons, enabling researchers to visualize and study the activity of neural circuits in real-time.
• Circuit tracing - Our AAV vectors can be used to deliver genetic tracers such as fluorescent proteins or viral reporters to specific neurons, allowing researchers to trace neural circuits and map connectivity within the brain.
• RNA interference - Our AAV services also offer the delivery of siRNA or shRNA to target specific genes within neural circuits, enabling researchers to study the role of these genes in neural function and behavior.

FAQs

Q: How do you handle large-scale AAV vector production for in vivo studies?

A: For large-scale AAV vector production, we employ scalable bioreactor systems that ensure high yields and consistent quality. Our process includes high-density cell culture techniques and optimized transfection protocols. We also offer large-volume purification and concentration methods to produce sufficient quantities for extensive in vivo studies. Our large-scale production services are designed to support high-throughput and long-term experiments.

Q: What specific AAV vectors do you offer for neural circuitry research?

A: We offer a variety of AAV vectors specifically designed for neural circuitry research, including but not limited to AAV-hSyn-GFP, AAV-CaMKIIa-Cre, and AAV-EF1a-DIO-mCherry. Each vector is optimized for targeting specific neuronal populations and pathways. Our catalog includes serotypes such as AAV1, AAV2, AAV5, AAV8, and AAV9 to ensure efficient transduction in different brain regions and cell types.

Q: What is the typical turnaround time for AAV vector production?

A: The typical turnaround time for our AAV vector production ranges from 4 to 6 weeks, depending on the complexity of the vector design and the volume required. This timeline includes vector cloning, packaging, purification, and quality control testing. We strive to expedite the process while maintaining high standards of quality to meet your research timelines.

Q: What is the cost structure for your AAV services?

A: Our pricing for AAV services depends on the specific requirements of your project, including vector design, serotype selection, and production scale. We offer competitive pricing and provide detailed quotes based on your needs. Contact our sales team to discuss your project in detail and obtain a customized quote that aligns with your budget.

Scientific Resources

Comparison of Various Viral Vectors in the Central Nervous System

References

1. Wang, Y.; et al. Viral vectors as a novel tool for clinical and neuropsychiatric research applications. General psychiatry. 2018, 31(2).
2. Haggerty, D.; et al. Adeno-associated viral vectors in neuroscience research. Molecular Therapy-Methods & Clinical Development. 2020, 17: 69-82.
3. Chen, Yefei, et al. "A novel retrograde AAV variant for functional manipulation of cortical projection neurons in mice and monkeys." Neuroscience Bulletin 40.1 (2024): 90-102.

For Research Use Only. Not For Clinical Use.