Published: February 18th, 2021
We describe how to successfully inject solutions into specific brain areas of rodents using a stereotaxic frame. This survival surgery is a well-established method used to mimic various aspects of Parkinson's disease.
Parkinson's disease (PD) is a progressive disorder traditionally defined by resting tremor and akinesia, primarily due to loss of dopaminergic neurons in the substantia nigra. Affected brain areas display intraneuronal fibrillar inclusions consisting mainly of alpha-synuclein (asyn) proteins. No animal model thus far has recapitulated all characteristics of this disease. Here, we describe the use of stereotaxic injection to deliver chemicals, proteins, or viral vectors intracranially in order to mimic various aspects of PD. These methods are well-established and widely used throughout the PD field. Stereotaxic injections are incredibly flexible; they can be adjusted in concentration, age of animal used for injection, brain area targeted and in animal species used. Combinations of substances allow for rapid variations to assess treatments or alter severity of the pathology or behavioral deficits. By injecting toxins into the brain, we can mimic inflammation and/or a severe loss of dopaminergic neurons resulting in substantial motor phenotypes. Viral vectors can be used to transduce cells to mimic genetic or mechanistic aspects. Preformed fibrillar asyn injections best recapitulate the progressive phenotype over an extended period of time. Once these methods are established, it can be economical to generate a new model compared to creating a new transgenic line. However, this method is labor intensive as it requires 30 minutes to four hours per animal depending on the model used. Each animal will have a slightly different targeting and therefore create a diverse cohort which on one hand can be challenging to interpret results from; on the other hand, help mimic a more realistic diversity found in patients. Mistargeted animals can be identified using behavioral or imaging readouts, or only after being sacrificed leading to smallercohort size after the study has already been concluded. Overall, this method is a rudimentary but effective way to assess a diverse set of PD aspects.
Parkinson's disease (PD) is a relatively common progressive neurodegenerative disease affecting up to 1 % of people over the age of 601. PD is heterogenousbut clinically characterized mainly by motor symptoms including resting tremor, bradykinesia, akinesia, rigidity, gait disturbance and postural instability. The majority of motor symptoms typically appear when 60-70% of striatal dopamine (DA) is lost as a result of progressive and distinct neurodegeneration in the substantia nigra (SN) pars compacta2,3. Surviving dopaminergic neurons contain intracellular inclusions known as Lewy ....
All experiments in this study were conducted in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health and approved by the Animal Care and Use Committees of the US National Institute on Aging.
Before starting, please make sure to have acquired the appropriate training and ethical approval from your institute necessary to perform this procedure. Additionally, anesthetics (e.g., ketamine and buprenorphine, or fentan.......
To avoid mistargeting, before every experiment, verify the coordinates using dye injections. Animals were injected with 0.2-0.5 µL tryptophan blue using the same protocol, capillary was rapidly withdrawn after injection and the brain was quickly frozen to avoid diffusion. After sectioning on the microtome, the injection site can be seen in blue (Figure 2 C,E). To ensure effective targeting, dye injections should be carried out successfully on 2-3 animals prior to actual.......
Stereotaxic injection, as any surgical procedure, has the main difficulty to guarantee the wellbeing and survival of the animal. Therefore, it is essential to monitor the animal closely throughout the procedure. Looking out for breathing irregularities, loss of breathing, or reoccurrence of reflexes and movements should be the main focus, especially for inexperienced surgeons. Additionally, the application of analgesics is crucial to help with the recovery process. Surgeries involving toxicants can be especially difficul.......
This research was supported in part by the Intramural Research Program of the National Institute of Health, National Institute on Aging. CES is supported by NS099416. The authors wish to acknowledge support by the NIMH IRP Rodent Behavioral Core (ZIC MH002952 and MH002952 to Yogita Chudasama) and by the NICHD IRP Microscopy and Imaging Core.....
|Allen brain atlas
|mouse brain - reference atlas
|analgesic: ketoprofin OR buprenorphine
|anesthetic: Isoflurane OR ketamine / xylazine OR fentanyl / medetomidine
|blades - surgical sterile
|capillaries - glass
|drill - dental
|eye drops (Liquigel)
|Carboxymethylcellulose Sodium (1%), Boric acid; calcium chloride; magnesium chloride; potassium chloride; purified water; PURITE® (stabilized oxychloro complex); sodium borate; and sodium chloride
|forceps - full curved
|forceps - hemostatic delicate
|gauze - cotton absorbent
|H2O - sterile
|Hamilton 5ul syringe
|Hamilton blunt metal needle
|heat pad - far infrared
|Iodine solution (Dynarex) 10%
|lighter / matches
|microscope (Stemi 508 Boom stand)
|Gibco - Thermo Fischer
|shaver - electrical
|solution to inject / material to implant
|stereotax - small animal digital
|sterilizer - glass bead
|BT Lab Systems
|tubing - heat-shrink
|tweezers - dumont fine curved
|underpad - absorbent
|vaporizer for isoflurane (package)
|wound clips and applier / remover
|wound glue (Vetbond)
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