【Animal modeling】-Establishment of animal model of sciatic nerve injury
动物模型,坐骨神经损伤
z-bo
2020-07-25
1160
1. Experimental purpose In the field of neurobiology, the factors affecting peripheral nerve repair after peripheral nerve injury are attracting people's attention. Known evidence shows that the main factors involved in nerve regeneration after peripheral nerve injury include the nerve center and local nerve microenvironment. In this chapter, we establish an animal model of sciatic nerve injury to study the behavioral changes after sciatic nerve transection. This laid the foundation for further research on the mechanisms and strategies of nerve injury repair.
二. Experimental principle
In this study, an animal model of rat sciatic nerve injury was created using mechanical amputation. By measuring the sciatic nerve conduction velocity, plantar thermal stimulation and plantar mechanical stimulation to measure the degree of injury in rats. Evaluation.
3. Experimental materials and methods
(1) Experimental materials
1. Required equipment, electric pressure steam sterilizer, miniature electronic balance, electric constant temperature drying oven, horizontal electrophoresis instrument, electric distilled water meter, 20μl, 100μl, 200μl, 1000μl adjustable micro sample gun, surgical equipment: ophthalmic scissors , Dissecting scissors, mosquito forceps, toothed forceps, toothless forceps. 2. The required reagents are 3.6% chloral hydrate, 75% ethanol, iodophor, 80,000 U/ml penicillin sodium, salt solution and glucose solution.
3. Reagent preparation 3.6% chlorine hydrate solution: 0.36g of chlorine hydrate was weighed, dissolved in 10ml of distilled water, mixed well and prepared. (II) Experimental method
1. Experimental animals and breeding environment This animal model uses 3-month-old female SD rats, weighing (200±10) g. The temperature of the laboratory animal room is 18~19℃, the relative humidity is 40%~70%, the number of air changes per hour is 10~20, the noise is less than 60dB, the ammonia concentration per cubic meter is less than 14mg, and lighting is used. It is 150-300lx. Feed water every day, change the cat litter 2-3 times a week, destroy the model, and then feed it to another cage. 2. Divide 10 adult SD rats with sciatic nerve injury into 2 groups, 5 sham operation groups, 5 experimental groups, 1d group, 2d group, and 7d group. The right lower abdomen of the rat was shaved and disinfected, a needle was inserted 0.5 cm above the midpoint of the groin and groin, and 3.6% chloral hydrate (1 ml/100 g) was injected intraperitoneally for anesthesia. Pay attention to the heat preservation during the anesthesia, record the start time and end time of each rat in detail, and estimate the blood loss for postoperative treatment and care. The animals in each experimental group were fixed on the operating table, the skin was cut with a scalpel, the gluteus maximus was stripped, and the thick sciatic nerve was exposed. After performing blunt dissection on the back of the forceps and the knife, the left sciatic nerve was cut with the scalpel. After confirming the incision, perform aseptic suture.
After surgery: Please keep the animal warm after the injury. After waking up naturally, place the animal in another cage with plenty of natural light and good ventilation. Change and dry the bedding often in a clean, dry cage. Hands and feet immersed in the liquid should be washed with medium-temperature soapy water and dried with a hair dryer. Fortify and feed eggs and sunflower seeds to keep feed and drinking water within the reach of animals. Carefully observe the animal's mental state, diet and urination: defecation, swelling of limbs and compression injuries, blood secretion in the urinary system, etc.: Plantar ulcers usually become complicated after injury, so strengthened care is needed; prevent self-harm; prevent intestines obstruction. 3. Evaluation of nerve function After the sciatic nerve is transected, the sciatic nerve conduction velocity measurement, plantar thermal stimulation and plantar mechanical stimulation are used to evaluate the nerve function damage of rats.
IV. Experimental results
After the sciatic nerve is transectioned, compared with the healthy side, the sciatic nerve conduction velocity on the injured side of the rat is slower, the amplitude is reduced, and the reflex latency is prolonged. The injured side's response to physical stimulation was significantly delayed.
5. Analysis results
Sciatic nerve injury is one of the most difficult and effective injuries of peripheral nerve injury. Each diseased segment is closely related to the topography. In this chapter, the author created a mechanical anatomical model of the sciatic nerve of the upper limb of a unilateral rat, and a mechanical anatomical model of the lower part of the ischial tuberosity after the injury. And all the muscles of the legs are paralyzed, muscle strength and tone are significantly reduced, nerve conduction speed is reduced, wave amplitude is reduced, reflex latency is prolonged, and thermal and mechanical stimulation. Appears in a significant delay in response. It shows that the model is successful.
