We thank Hanns Ulrich Zeilhofer for generously supporting this work. Hendrik Wildner was supported by the Olga Mayenfisch foundation. We thank Carmen Birchmeier for the Lmx1b antibody.

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</ol>

The authors have nothing to disclose.

Intraspinal injection of AAVs may become a powerful technique in a research laboratory, enabling the analysis of spinal cells with a high temporal and spatial solution. This protocol enables the transduction of the three main spinal segments innervated by sensory neurons extending their peripheral axons to the hindlimb. Transducing three segments produces robust and reproducible behavioral data. It also enables testing of a larger sensory area than possible after a single intraspinal injection. For example, the same inje...

The dorsal spinal cord is essential for information exchange between the periphery of the body and the brain. Sensory stimuli such as heat, cold, touch, or noxious stimuli are detected by specialized peripheral neurons, which convey this information to neurons of the spinal cord dorsal horn. Here, a complex network of inhibitory and excitatory interneurons modulates and eventually relays sensory information via spinal projection neurons to supraspinal sites1,2. The computations carried out by spinal inter- and projection neurons gate sensory information, thus determining which information is suppressed or relayed at which intensity. Changes in the integration of sensory stimuli, such as an altered balance between inhibition and excitation, can cause sensory dysfunctions such as hypersensitivity or allodynia (painful sensations after normally non-painful stimulation). These changes are thought to be the underlying cause of various chronic pain states3,4. Thus, spinal circuits are of high importance in sensory processing and consequently in the perception of an organism&#39;s environment and self. With the recent advent and combination of molecular, genetic, and surgical techniques that allow the precise manipulation of genetically identified spinal neuron subpopulations, scientists are now beginning to understand the underlying spinal circuits responsible for the processing of distinct sensory modalities.
Intraspinal injection of rAAV into wild-type or transgenic mice has greatly contributed to the manipulation, analysis, and understanding of the function of specific subsets of spinal neurons5,6,7,8,9,10,11. This technique allows the delivery of marker proteins (such as GFP/ GFP fusion proteins), reporter proteins (such as GCaMP), or effector proteins (such as bacterial toxins, channelrhodopsin, or pharmacogenetic receptors) in a spatially restricted manner to spinal neurons. Local injection of Cre-dependent rAAVs into transgenic mice expressing Cre recombinase in a specific subset of spinal neurons allows the specific analysis of the respective neuronal population. We have employed this technique to label, ablate, inhibit or activate spinal glycinergic neurons demonstrating that they are an essential part of the spinal gate controlling pain and itch transmission7. In these experiments, intraspinal injection of Cre-dependent rAAV into GlyT2::Cre mice enabled the selective manipulation of glycinergic neurons in the lumbar spinal cord. Thereby, simultaneous manipulation of supraspinal circuits that contain glycinergic neurons critical for the survival of the animal can be avoided.
While an intraspinal injection of rAAVs limits infection to the site of injection, viral transduction can occur not only in local neurons but also in neurons that connect to the injection site via axonal projections. The latter is often used to trace CNS areas providing neuronal input to a particular nucleus in the brain. The infection of axonal projections can, however, also be a confounding factor when a defined population of neurons shall be studied at a particular site. To address these issues, we have recently conducted a comprehensive analysis of AAV serotypes and expression cassettes to identify serotypes and promoters that can be used to either minimize or maximize retrograde transduction. In the context of this specific research in spinal circuits, we analyzed the ability of different serotypes and promoters to retrogradely transduce neurons in the dorsal root ganglia (DRG), the rostral ventromedial medulla (RVM), and the somatosensory cortex12. The technique outlined in this protocol can therefore be used either to analyze spinal neurons at the injection site or to analyze projection neurons that provide input to the injected site of the spinal cord. In the protocol described here, three injections of rAAV into the left side of the lumbar spinal cord are performed to enable transduction of neurons in the three lumbar segments (L3-L5). The L3-L5 segments receive the majority of the sensory input from the hindlimb ipsilateral to the injection site. We demonstrate that functional manipulation of genetically labeled neurons in L3-L5 is sufficient to evoke robust behavioral changes, thus providing functional evidence for the circuit function of such a genetically labeled neuron subtype.

<table><tbody><tr><td>&lt;strong&gt;Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>micropipette puller: DMZ-Universal-Electrode-Puller</td><td>Zeitz</td><td>NA</td><td></td></tr><tr><td>anesthesia unit: Oxymat3 oxygen concentrator</td><td>Weinmann</td><td>NA</td><td></td></tr><tr><td>anesthesia unit: VIP 3000 Veterinary Vaporizer</td><td>Midmark</td><td>NA</td><td></td></tr><tr><td>Heat mat: Mio Star Thermocare 100</td><td>Migros</td><td>717614700000</td><td></td></tr><tr><td>Electric shaver</td><td>Philips</td><td>BT9290</td><td></td></tr><tr><td>surgical microscope (OPMI pico)</td><td>Zeiss</td><td>NA</td><td></td></tr><tr><td>Small animal stereotaxic apparatus</td><td>Kopf</td><td>NA</td><td></td></tr><tr><td>Neurostar StereoDrive (optional)</td><td>Neurostar</td><td>NA</td><td></td></tr><tr><td>Model 51690 Cunningham mouse spinal adaptor</td><td>Harvard Apparatus</td><td>72-4811</td><td></td></tr><tr><td>PHD Ultra syringe pump with nanomite</td><td>Harvard Apparatus</td><td>70-3601</td><td></td></tr><tr><td>Hamilton 701 RN 10 &amp;mu;l glass microliter syringe</td><td>Hamilton</td><td>7635-01</td><td></td></tr><tr><td>Hamilton Removable needle (RN) compression fitting 1 mm</td><td>Hamilton</td><td>55750-01</td><td></td></tr><tr><td>fine dentistry drilling apparatus: Osada success 40</td><td>Osada</td><td>OS-40</td><td></td></tr><tr><td>spherical cutter, 0.5mm</td><td>Busch</td><td>12001005B</td><td></td></tr><tr><td>electronic von Frey anesthesiometer</td><td>IITC</td><td>23905</td><td></td></tr><tr><td>flexible von Frey hairs</td><td>IITC</td><td>#7</td><td></td></tr><tr><td>LSM710 Pascal confocal microscope</td><td>Zeiss</td><td>NA</td><td></td></tr><tr><td>0.8 NA &amp;times; 20 Plan-apochromat objective</td><td>Zeiss</td><td>NA</td><td></td></tr><tr><td>1.3 NA &amp;times; 40 EC Plan-Neofluar oil-immersion objective</td><td>Zeiss</td><td>NA</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Surgical Tools&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Scalpel Handle #4, 13cm</td><td>Fine Science Tools</td><td>10004-13</td><td></td></tr><tr><td>Extra Fine Bonn Scissors</td><td>Fine Science Tools</td><td>14084-08</td><td></td></tr><tr><td>Adson forceps, 1 x 2 teeth, 12 cm</td><td>Fine Science Tools</td><td>11027-12</td><td></td></tr><tr><td>Friedman-Pearson rongeurs, curved, 0.7 mm cup</td><td>Fine Science Tools</td><td>16121-14</td><td></td></tr><tr><td>Dumont #2 laminectomy forceps</td><td>Fine Science Tools</td><td>11223-20</td><td></td></tr><tr><td>Olsen-Hegar needle holders, serrated, 8.5 mm clamp length</td><td>Fine Science Tools</td><td>12002-12</td><td></td></tr><tr><td>Fine forceps #5</td><td>Fine Science Tools</td><td>11254-20</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Consumables and Chemicals&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Thin-wall glass capillary, 1mm outside diameter</td><td>World Precision Instruments</td><td>TW 100-3</td><td></td></tr><tr><td>Syringes (1, 5 and 20 ml)</td><td>B. Braun</td><td>(9166917V, 4606051V, 4606205V)</td><td></td></tr><tr><td>26G beveled needle</td><td>B. Braun</td><td>4665457</td><td></td></tr><tr><td>Sterile scalpel blades</td><td>B. Braun</td><td>BB523</td><td></td></tr><tr><td>Surgical sutures Safil Quick+ 4/0, absorbable</td><td>B. Braun</td><td>C1046220</td><td></td></tr><tr><td>Surgical sutures Premilene 5/0, non-absorbable</td><td>B. Braun</td><td>C0932191</td><td></td></tr><tr><td>Sterile PBS or saline (0.9%)</td><td></td><td>NA</td><td></td></tr><tr><td>Ethanol, 70% (disinfectant)</td><td></td><td>NA</td><td></td></tr><tr><td>Iodine solution (e.g. Braunol)</td><td>B. Braun</td><td>18380</td><td></td></tr><tr><td>Anaesthetics (e.g. Attane isoflurane)</td><td>Provet</td><td>2222</td><td></td></tr><tr><td>Aldasorber</td><td>Provet</td><td>333526</td><td></td></tr><tr><td>analgesics (e.g. buprenorphine: temgesic)</td><td>Indivior</td><td>GTIN: 7680419310018</td><td></td></tr><tr><td>Ophthalmic ointment (e.g. vita-pos)</td><td>Pharma medica</td><td>GTIN: 4031626710635</td><td></td></tr><tr><td>Cotton swabs (e.g. from)</td><td>IVF Hartmann</td><td>1628100</td><td></td></tr><tr><td>Facial tissues (e.g. from)</td><td>Uehlinger AG</td><td>2015.10018</td><td></td></tr><tr><td>Superfrost plus microscope slides</td><td>ThermoScientific</td><td>J1800AMNZ</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Mice&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>C57BL/6J mice (wildtype)</td><td>The Jackson Laboratory</td><td>RRID:IMSR_JAX:000664</td><td></td></tr><tr><td>Rorbtm1.1(cre)Hze/J mice (ROR&amp;beta;Cre)</td><td>The Jackson Laboratory</td><td>RRID:IMSR_JAX:023526</td><td></td></tr><tr><td>Gt(ROSA)26Sortm14(CAG-tdTomato)Hze/J mice (R26Tom)</td><td>The Jackson Laboratory</td><td>RRID: IMSR_JAX:007914</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Viral vectors&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>AAV1.CB7.CI.eGFP.WPRE.rBG (AAV1.CAG.eGFP)</td><td>Penn Vector Core</td><td>AV-1-PV1963</td><td></td></tr><tr><td>AAV1.CAG.flex.eGFP.WPRE.bGH (AAV1.CAG.flex.eGFP)</td><td>Penn Vector Core</td><td>AV-1-ALL854</td><td></td></tr><tr><td>AAV1.CAG.flex.tdTomato.WPRE&lt;br /&gt;.bGH (AAV1.CAG.flex.tdTomato)</td><td>Penn Vector Core</td><td>AV-1-ALL864</td><td></td></tr><tr><td>AAV1.EF1a.flex.DTA.hGH (AAV1.EF1a.flex.DTA)</td><td>Penn Vector Core</td><td>Custom production</td><td></td></tr><tr><td>AAV1.hSyn.DIO.hM3D(Gq)-mCherry.hGH (AAV.flex.hM3D(Gi))</td><td>Penn Vector Core</td><td>Custom production</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Plasmids&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>pAAV.hSyn.flex.hM3D(Gq)-mCherry</td><td>Addgene</td><td>44361</td><td></td></tr><tr><td>pAAV.EF1&amp;alpha;.flex.hChR2(H134R)-eYFP</td><td>Addgene</td><td>20298</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Bacteria&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>MDS42</td><td>ScarabGenomics</td><td></td><td></td></tr><tr><td>Stbl3</td><td>ThermoScientific</td><td>C737303</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Reagents&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>EndoFree Plasmid Maxi Kit</td><td>Quiagen</td><td>12362</td><td></td></tr><tr><td>NucleoBond PC 500</td><td>Machery &amp;amp; Nagel</td><td>740574</td><td></td></tr><tr><td>clozapine-N-oxide (CNO)</td><td>Enzo Life Sciences</td><td>BBL-NS105-0025</td><td></td></tr><tr><td>chloroquine diphosphate salt</td><td>Sigma</td><td>C6628</td><td></td></tr><tr><td>histamine</td><td>Sigma</td><td>H7125</td><td></td></tr><tr><td>Dapi</td><td>Invitrogen</td><td>D3571</td><td></td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Antibodies (dilution)&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Rabbit anti-GFP (1:1000)</td><td>Molecular Probes</td><td>RRID:AB_221570</td><td></td></tr><tr><td>Rabbit anti-NeuN (1:3000)</td><td>Abcam</td><td>RRID:AB_10711153</td><td></td></tr><tr><td>Goat anti-Pax2 (1 : 200)</td><td>R &amp;amp; D Systems</td><td>RRID:AB_10889828</td><td></td></tr><tr><td>Guinea pig anti-Lmx1b (1 : 10 000)</td><td>Dr Carmen Birchmeier</td><td>Muller et al. 2002</td><td></td></tr><tr><td>Rabbit anti-GFAP (1 : 1000)</td><td>DakoCytomation</td><td>RRID:AB_10013382</td><td></td></tr><tr><td>Secondary antibodies raised in donkey (1:800)</td><td>Jackson ImmunoResearch Laboratories</td><td>NA</td><td></td></tr></tbody></table>

adeno-associated virus-mediated transgene expression in genetically defined neurons of the spinal cord

Selective manipulation of spinal neuronal subpopulations has mainly been achieved by two different methods: 1) Intersectional genetics, whereby double or triple transgenic mice are generated in order to achieve selective expression of a reporter or effector gene (e.g., from the Rosa26 locus) in the desired spinal population. 2) Intraspinal injection of Cre-dependent recombinant adeno-associated virus (rAAV); here Cre-dependent AAV vectors coding for the reporter or effector gene of choice are injected into the spinal cord of mice expressing Cre recombinase in the desired neuronal subpopulation. This protocol describes how to generate Cre-dependent rAAV vectors and how to transduce neurons in the dorsal horn of the lumbar spinal cord segments L3-L5 with rAAVs. As the lumbar spinal segments L3-L5 are innervated by those peripheral sensory neurons that transmit sensory information from the hindlimbs, spontaneous behavior and responses to sensory tests applied to the hindlimb ipsilateral to the injection side can be analyzed in order to interrogate the function of the manipulated neurons in sensory processing. We provide examples of how this technique can be used to analyze genetically defined subsets of spinal neurons. The main advantages of virus-mediated transgene expression in Cre transgenic mice compared to classical reporter mouse-induced transgene expression are the following: 1) Different Cre-dependent rAAVs encoding various reporter or effector proteins can be injected into a single Cre transgenic line, thus overcoming the need to create several multiple transgenic mouse lines. 2) Intraspinal injection limits manipulation of Cre-expressing cells to the injection site and to the time after injection. The main disadvantages are: 1) Reporter gene expression from rAAVs is more variable. 2) Surgery is required to transduce the spinal neurons of interest. Which of the two methods is more appropriate depends on the neuron population and research question to be addressed.

In order to illustrate the expression levels that can be obtained by the intraspinal injection of rAAV encoding a marker protein, we first injected AAV1.CAG.eGFP into the lumbar spinal cord of wild-type mice. Three injections spaced approximately 1 mm apart produced a nearly continuous infection of lumbar spinal segments L3 to L5 (Figure 1A-C). Virus injection at a depth of 300 &#181;m from the spinal surface leads to predominant infection of...

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Adeno-associated Virus-mediated Transgene Expression in Genetically Defined Neurons of the Spinal Cord

Intraspinal injection of recombinase dependent recombinant adeno-associated virus (rAAV) can be used to manipulate any genetically labelled cell type in the spinal cord. Here we describe how to transduce neurons in the dorsal horn of the lumbar spinal cord. This technique enables functional interrogation of the manipulated neuron subtype.

Selective manipulation of spinal neuronal subpopulations has mainly been achieved by two different methods: 1) Intersectional genetics, whereby double or ...

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Neuroscience

18.0K Views.  University of Zurich. Intraspinal injection of recombinase dependent recombinant adeno-associated virus (rAAV) can be used to manipulate any genetically labelled cell type in the spinal cord. Here we describe how to transduce neurons in the dorsal horn of the lumbar spinal cord. This technique enables functional interrogation of the manipulated neuron subtype.

Video: Adeno-associated Virus-mediated Transgene Expression in Genetically Defined Neurons of the Spinal Cord

Intracranial Injection of Adeno-associated Viral Vectors

Intracranial injection of viral vectors engineered to express a fluorescent protein is a versatile labeling technique for visualization of specific subsets of cells in different brain regions both in vivo and in brain sections. Unlike the injection of fluorescent dyes, viral labeling offers targeting of individual cell types and is less expensive and time consuming than establishing transgenic mouse lines. In this technique, an adeno-associated viral (AAV) vector is injected intracranially using stereotaxic coordinates, a micropipette and an automated pump for precise delivery of AAV to the desired area with minimal damage to the surrounding tissue. Injection parameters can be tailored to individual experiments by adjusting the animal age at injection, injection location, volume of injection, rate of injection, AAV serotype and the promoter driving gene expression. Depending on the conditions chosen, virally-induced transgene expression can allow visualization of groups of cells, individual cells or fine cellular processes, down to the level of dendritic spines. The experiment shown here depicts an injection of double-stranded AAV expressing green fluorescent protein for the labeling of neurons and glia in the mouse primary visual cortex.

Here we present the intracranial injection of AAV vectors for fluorescent labeling of neurons and glia in the visual cortex.

Intracranial injection of viral vectors engineered to express a fluorescent protein is a versatile labeling technique for visualization of specific ...

Stereotaxic Injection of a Viral Vector for Conditional Gene Manipulation in the Mouse Spinal Cord

Intraparenchymal injection of a viral vector enables conditional gene manipulation in distinct populations of neurons or particular regions of the central nervous system. We demonstrate a stereotaxic injection technique that allows targeted gene expression or silencing in the dorsal horn of the mouse spinal cord. The surgical procedure is brief. It requires laminectomy of a single vertebra, providing for quick recovery of the animal and unimpaired motility of the spine. Controlled injection of a small vector suspension volume at low speed and use of a microsyringe with beveled glass cannula minimize the tissue lesion. The local immune response to the vector depends on the intrinsic properties of the virus employed; in our experience, it is minor and short-lived when a recombinant adeno-associated virus is used. A reporter gene such as enhanced green fluorescent protein facilitates monitoring spatial distribution of the vector, and the efficacy and cellular specificity of the transfection.

Viral vectors allow for targeted gene manipulation. We demonstrate a method for conditional gene expression or ablation in the mouse spinal cord, using stereotaxic injection of a viral vector into the dorsal horn, a prominent site of synaptic contact between primary somatosensory afferents and neurons of the central nervous system.

Intraparenchymal injection of a viral vector enables conditional gene manipulation in distinct populations of neurons or particular regions of the central ...

Intracerebroventricular Viral Injection of the Neonatal Mouse Brain for Persistent and Widespread Neuronal Transduction

With the pace of scientific advancement accelerating rapidly, new methods are needed for experimental neuroscience to quickly and easily manipulate gene expression in the mouse brain. Here we describe a technique first introduced by Passini and Wolfe for direct intracranial delivery of virally-encoded transgenes into the neonatal mouse brain. In its most basic form, the procedure requires only an ice bucket and a microliter syringe. However, the protocol can also be adapted for use with stereotaxic frames to improve consistency for researchers new to the technique. The method relies on the ability of adeno-associated virus (AAV) to move freely from the cerebral ventricles into the brain parenchyma while the ependymal lining is still immature during the first 12-24 hr after birth. Intraventricular injection of AAV at this age results in widespread transduction of neurons throughout the brain. Expression begins within days of injection and persists for the lifetime of the animal. Viral titer can be adjusted to control the density of transduced neurons, while co-expression of a fluorescent protein provides a vital label of transduced cells. With the rising availability of viral core facilities to provide both off-the-shelf, pre-packaged reagents and custom viral preparation, this approach offers a timely method for manipulating gene expression in the mouse brain that is fast, easy, and far less expensive than traditional germline engineering.

Here we demonstrate a technique for widespread neuronal transduction by intraventricular injection of adeno-associated virus into the neonatal mouse brain. This method provides a rapid and easy way to attain lifelong expression of virally-delivered transgenes.

With the pace of scientific advancement accelerating rapidly, new methods are needed for experimental neuroscience to quickly and easily manipulate gene ...

In Vivo Gene Transfer to Schwann Cells in the Rodent Sciatic Nerve by Electroporation

The formation of the myelin sheath by Schwann cells (SCs) is essential for rapid conduction of nerve impulses along axons in the peripheral nervous system. SC-selective genetic manipulation in living animals is a powerful technique for studying the molecular and cellular mechanisms of SC myelination and demyelination in vivo. While knockout/knockin and transgenic mice are powerful tools for studying SC biology, these methods are costly and time consuming. Viral vector-mediated transgene introduction into the sciatic nerve is a simpler and less laborious method. However, viral methods have limitations, such as toxicity, transgene size constraints, and infectivity restricted to certain developmental stages. Here, we describe a new method that allows selective transfection of myelinating SCs in the rodent sciatic nerve using electroporation. By applying electric pulses to the sciatic nerve at the site of plasmid DNA injection, genes of interest can be easily silenced or overexpressed in SCs in both neonatal and more mature animals. Furthermore, this in vivo electroporation method allows for highly efficient simultaneous expression of multiple transgenes. Our novel technique should enable researchers to efficiently manipulate SC gene expression, and facilitate studies on SC development and function.

In Vivo Gene Transfer to Schwann Cells in the Rodent Sciatic Nerve by Electroporation

Here, we present an in vivo technique for gene transfer to Schwann cells (SCs) in the rodent sciatic nerve. This simple technique is useful for investigating signaling mechanisms involved in the development and maintenance of myelinating SCs.

The formation of the myelin sheath by Schwann cells (SCs) is essential for rapid conduction of nerve impulses along axons in the peripheral nervous ...

Dorsal Root Ganglion Injection and Dorsal Root Crush Injury as a Model for Sensory Axon Regeneration

Achieving axon regeneration after nervous system injury is a challenging task. As different parts of the central nervous system (CNS) differ from each other anatomically, it is important to identify an appropriate model to use for the study of axon regeneration. By using a suitable model, we can formulate a specific treatment based on the severity of injury, the neuronal cell type of interest, and the desired spinal tract for assessing regeneration. Within the sensory pathway, DRG neurons are responsible for relaying sensory information from the periphery to the CNS. We present here a protocol that uses a DRG injection with a viral vector and a concurrent dorsal root crush injury in the lower cervical spinal cord of an adult rat as a model to study sensory axon regeneration. As demonstrated using a control virus, AAV5-GFP, we show the effectiveness of a direct DRG injection in transducing DRG neurons and tracing sensory axons into the spinal cord. We also show the effectiveness of the dorsal root crush injury in denervating the forepaw as an injury model for evaluating axon regeneration. Despite the requirement for specialized training to perform this invasive surgical procedure, the protocol is flexible, and potential users can modify many parts to accommodate their experimental requirements. Importantly, it can serve as a foundation for those in search of a suitable animal model for their studies. We believe that this article will help new users to learn the procedure in a very efficient and effective manner.

This protocol presents the use of a dorsal root ganglion (DRG) injection with a viral vector and a concurrent dorsal root crush injury in an adult rat as a model to study sensory axon regeneration. This model is suitable for investigating the use of gene therapy to promote sensory axon regeneration.

Achieving axon regeneration after nervous system injury is a challenging task. As different parts of the central nervous system (CNS) differ from each ...

Subpial Adeno-associated Virus 9 (AAV9) Vector Delivery in Adult Mice

The successful development of a subpial adeno-associated virus 9 (AAV9) vector delivery technique in adult rats and pigs has been reported on previously. Using subpially-placed polyethylene catheters (PE-10 or PE-5) for AAV9 delivery, potent transgene expression through the spinal parenchyma (white and gray matter) in subpially-injected spinal segments has been demonstrated. Because of the wide range of transgenic mouse models of neurodegenerative diseases, there is a strong desire for the development of a potent central nervous system (CNS)-targeted vector delivery technique in adult mice. Accordingly, the present study describes the development of a spinal subpial vector delivery device and technique to permit safe and effective spinal AAV9 delivery in adult C57BL/6J mice. In spinally immobilized and anesthetized mice, the pia mater (cervical 1 and lumbar 1-2 spinal segmental level) was incised with a sharp 34 G needle using an XYZ manipulator. A second XYZ manipulator was then used to advance a blunt 36G needle into the lumbar and/or cervical subpial space. The AAV9 vector (3-5 &#181;L; 1.2 x 1013 genome copies (gc)) encoding green fluorescent protein (GFP) was then injected subpially. After injections, neurological function (motor and sensory) was assessed periodically, and animals were perfusion-fixed 14 days after AAV9 delivery with 4% paraformaldehyde. Analysis of horizontal or transverse spinal cord sections showed transgene expression throughout the entire spinal cord, in both gray and white matter. In addition, intense retrogradely-mediated GFP expression was seen in the descending motor axons and neurons in the motor cortex, nucleus ruber, and formatio reticularis. No neurological dysfunction was noted in any animals. These data show that the subpial vector delivery technique can successfully be used in adult mice, without causing procedure-related spinal cord injury, and is associated with highly potent transgene expression throughout the spinal neuraxis.

Subpial Adeno-associated Virus 9 AAV9 Vector Delivery in Adult Mice

The goal of the present study was to develop and validate the potency and safety of spinal adeno-associated virus 9 (AAV9)-mediated gene delivery by using a novel subpial gene delivery technique in adult mice.

The successful development of a subpial adeno-associated virus 9 (AAV9) vector delivery technique in adult rats and pigs has been reported on previously. ...

Methods and Tips for Intravenous Administration of Adeno-associated Virus to Rats and Evaluation of Central Nervous System Transduction

Adeno-associated virus (AAV) vectors are a key reagent in the neurosciences for clustered regularly interspaced short palindromic repeats (CRISPR), optogenetics, cre-lox targeting, etc. The purpose of this manuscript is to aid the investigator attempting expansive central nervous system (CNS) gene transfer in the rat via tail vein injection of AAV. Wide-scale expression is relevant for conditions with widespread pathology, and a rat model is significant due to its greater size and physiologic similarities to humans compared to mice. In this example application, a wide-scale neuronal transduction is used to mimic a neurodegenerative disease that affects the entire spinal cord, amyotrophic lateral sclerosis (ALS). The efficient wide-scale CNS transduction can also be used to deliver therapeutic protein factors in pre-clinical studies. After a post-injection expression interval of several weeks, the effects of the transduction are evaluated. For a green fluorescent protein (GFP) control vector, the amount of GFP in the cerebellum is estimated quickly and reliably by a basic imaging program. For motor disease phenotypes that are induced by the ALS related protein transactive response DNA-binding protein of 43 kDa (TDP-43), the deficits are scored by escape reflex and rotarod. Beyond disease modeling and gene therapy, there are diverse potential applications for the wide-scale gene targeting described here. The expanded use of this method will aid in expediting hypothesis testing in the neurosciences and neurogenetics.

Methods for a wide-scale central nervous system gene delivery in the rat are covered. In this example, the purpose is to mimic a disease that affects the entire spinal cord. The widespread transduction can be used to deliver a therapeutic protein to the CNS from a one-time, peripheral administration.

Adeno-associated virus (AAV) vectors are a key reagent in the neurosciences for clustered regularly interspaced short palindromic repeats (CRISPR), ...

Direct Intrathecal Injection of Recombinant Adeno-associated Viruses in Adult Mice

Intrathecal (IT) injection of adeno-associated virus (AAV) has drawn considerable interest in CNS gene therapy by virtue of its safety, noninvasiveness, and excellent transduction efficacy in the CNS.&#160;Previous studies have demonstrated the therapeutic potency of AAV-delivered gene therapy in neurodegenerative disorders by IT administration. However, high rates of unpredictable failure due to the technical limitation of IT administration in small animals have been reported. Here, we established a scoring system to indicate the success extent of lumbar puncture in small animals by adding 1% lidocaine hydrochloride into the injection solution. We further show that the extent of transient weakness following injection can predict the transduction efficiency of AAV. Thus, this IT injection method can be used to optimize therapeutic trials in mouse models of CNS diseases that afflict wide regions of the CNS.

Here we present a direct intrathecal injection technique using 1% lidocaine hydrochloride in a viral solution to ensure efficient adeno-associated virus delivery to small animals and establish a scoring system to predict transduction efficiency in the central nervous system according to the degree of transient weakness induced by lidocaine.

Intrathecal (IT) injection of adeno-associated virus (AAV) has drawn considerable interest in CNS gene therapy by virtue of its safety, noninvasiveness, ...

Direct Injection of a Lentiviral Vector Highlights Multiple Motor Pathways in the Rat Spinal Cord

Introducing proteins of interest into cells in the nervous system is challenging due to innate biological barriers that limit access to most molecules. Injection directly into spinal cord tissue bypasses these barriers, providing access to cell bodies or synapses where molecules can be incorporated. Combining viral vector technology with this method allows for introduction of target genes into nervous tissue for the purpose of gene therapy or tract tracing. Here a virus engineered for highly efficient retrograde transport (HiRet) is introduced at the synapses of propriospinal interneurons (PNs) to encourage specific transport to neurons in the spinal cord and brainstem nuclei. Targeting PNs takes advantage of the numerous connections they receive from motor pathways such as the rubrospinal and reticulospinal tracts, as well as their interconnection with each other throughout spinal cord segments. Representative tracing using the HiRet vector with constitutively active green fluorescent protein (GFP) shows high fidelity details of cell bodies, axons and dendritic arbors in thoracic PNs and in reticulospinal neurons in the pontine reticular formation. HiRet incorporates well into brainstem pathways and PNs but shows age dependent integration into corticospinal tract neurons. In summary, spinal cord injection using viral vectors is a suitable method for introduction of proteins of interest into neurons of targeted tracts.

This protocol demonstrates injection of a retrogradely transportable viral vector into rat spinal cord tissue. The vector is taken up at the synapse and transported to the cell body of target neurons. This model is suitable for retrograde tracing of important spinal pathways or targeting cells for gene therapy applications.

Introducing proteins of interest into cells in the nervous system is challenging due to innate biological barriers that limit access to most molecules. ...

Targeting the Corticospinal Tract in Neonatal Rats with a Double-Viral Vector using Combined Brain and Spine Surgery

Successfully tackling the obstacles that constrain research on neonatal rats is important for studying the differences in outcomes seen in pediatric spinal cord injuries (SCIs) compared to adult SCIs. In addition, reliably introducing therapies into the target cells of the central nervous system (CNS) can be challenging, and inaccuracies can compromise the efficacy of the study or therapy. This protocol combines viral vector technology with a novel surgical technique&#160;to accurately introduce gene therapies into neonatal rats at postnatal day 5. Here, a virus engineered for retrograde transport (retroAAV2) of Cre is introduced at the axon terminals of corticospinal neurons in the spinal cord, where it is subsequently transported to the cell bodies. A double-floxed&#160;inverted orientation (DIO) designer receptor exclusively activated by designer drug(s) (DREADD) virus is then injected into the somatomotor cortex of the brain. This double-infection technique promotes the expression of the DREADDs only in the co-infected corticospinal tract (CST) neurons.&#160;Thus, the simultaneous co-injection of the somatomotor cortex and cervical CST terminals is a valid method for studying the chemogenetic modulation of recovery following cervical SCI models in neonatal rats.

This protocol demonstrates a novel method for applying gene therapies to subpopulations of cells in neonatal rats at postnatal ages 5-10 days by injecting an anterograde chemogenetic modifier into the somatomotor cortex and a retrogradely transportable Cre recombinase into the cervical spinal cord.

Successfully tackling the obstacles that constrain research on neonatal rats is important for studying the differences in outcomes seen in pediatric ...

Adeno-associated Virus-mediated Transgene Expression in Genetically Defined Neurons of the Spinal Cord

Summary

Explore More Videos

Intracranial Injection of Adeno-associated Viral Vectors

Stereotaxic Injection of a Viral Vector for Conditional Gene Manipulation in the Mouse Spinal Cord

Intracerebroventricular Viral Injection of the Neonatal Mouse Brain for Persistent and Widespread Neuronal Transduction

In Vivo Gene Transfer to Schwann Cells in the Rodent Sciatic Nerve by Electroporation

Dorsal Root Ganglion Injection and Dorsal Root Crush Injury as a Model for Sensory Axon Regeneration

Subpial Adeno-associated Virus 9 (AAV9) Vector Delivery in Adult Mice

Methods and Tips for Intravenous Administration of Adeno-associated Virus to Rats and Evaluation of Central Nervous System Transduction

Direct Intrathecal Injection of Recombinant Adeno-associated Viruses in Adult Mice

Direct Injection of a Lentiviral Vector Highlights Multiple Motor Pathways in the Rat Spinal Cord

Targeting the Corticospinal Tract in Neonatal Rats with a Double-Viral Vector using Combined Brain and Spine Surgery