动物造模,脊髓横断模型 z-bio 2021-04-01 531

　　With the new understanding of the plasticity of the central nervous system after injury, more and more scholars are devoted to the study of nerve regeneration after spinal cord injury. Many animal studies mainly use sharp blades for selective cutting. spinal cord. Formation, hemilateral, partial amputation or mass defect, spinal cord amputation, hemisection injury or spinal cord defect. The spinal cord was dissected to observe the effects of damaged axon regeneration, synaptic remodeling, neurotransmitters, neurotrophic factors, nerve tissue and cell transplantation, and loss of continuity and physiological connection. The influence and effect of this process. The amputation model is an injury caused by the loss of anatomical continuity of the spinal cord due to cutting with a scalpel. It can be divided into two damage models: full traversal and half traversal. For rodents, such as rat amputation models, you can choose to block specific conductive beams for amputation. For example, amputate the dorsolateral spinal cord to block the red nucleus spinal cord, and observe the changes in the motor function of the ipsilateral forelimb after injury.

　　1. Total spinal cord injury model Total spinal cord injury is the most serious type of spinal cord injury. It manifests as a complete amputation of the spinal cord. Once it occurs, all motor and sensory functions below the injury level will be quickly lost, and may be accompanied by autonomic dysfunction. At the same time, because the continuity of the spinal cord is completely blocked, there are no nerve fibers remaining on the injured surface, and the area of spinal cord ulcers after injury is larger. At the amputation end, even if there is nerve fiber regeneration, it is difficult to pass the injury, which will rebuild the complete spinal cord injury structure and make functional recovery more difficult. The resulting loss of sensation, spontaneous motor function or urine, and bowel dysfunction are related to the life of the patient.

　　Some researchers use a method of threading the ventral side of the spinal cord to completely cut the spinal cord. The general advantages of this model are easy to operate, clear scratches, less bleeding, minor secondary reactions, good repeatability, continuous damage, accurate anatomical positioning, identification of dysfunction, complete damage and can be eliminated The remaining fiber is regenerated for the evaluation of observational interference; its shortcomings are significantly different from the actual clinical damage, the repeatability is high, and the animal model is consistent, and it is difficult to fix. Some researchers believe that lateral amputation of the spinal cord is rare in spinal cord injuries. The tension of the spinal cord separates the ends of the two amputations, but in the case of human injuries, such cracks rarely appear. Spinal incision requires opening of the dura mater, which allows foreign cells to invade the spinal cord injury and significantly change the internal environment of the injury site. Postoperative care of animals is difficult and the mortality rate is high. Moreover, it is difficult to obtain the entire batch of data. This type of model is mainly used to study the repair and regeneration of spinal cord injury, and is an ideal choice for studying transplantation therapy experiments. Scholars at home and abroad mainly adopt this method. 2. 2. The cutting method of the hemisection injury model includes a spinal cord hemisection injury model made with a needle modified by a rotary incision needle. Vacuum suction can also be used to suck a portion of the spine. Spinal cord tissue forms a cavity. After creating the model, transplant the embryo transfer tissue into the cavity to observe the recovery of spinal cord function. From an anatomical point of view, dorsal root ganglion cells can be divided into three types: large, medium and small: large cells transmit fibers AA or AB in the posterior horn of the spinal cord, and direct proprioception in the posterior approach. Ipsilateral spinal cord. Small and medium-sized cells release fine fibers AD and C fibers, form synaptic exchange neurons with spinal dorsal horn cells, and then continue to release fibers. One or two spinal cord segments intersect with the anterior thoracic and lateral tracts of the spinal cord to convey pain and pain before the white traits. warm. Some C fibers are directly terminated by colloidal substances involved in pain regulation. These colloidal substances receive afferent nerves from the lamellar II neuron process and form synaptic connections with colloidal neurons and C fibers. Therefore, the amputation of the spinal cord inevitably damages the thick fibers of the large cells on the same side and the thin fibers that intersect from the opposite side, resulting in pain and increased body temperature. Therefore, the damage is on one side, but it will affect both sides.

　　Hemilateral injury can also be compared with the healthy side. This has its own advantages. However, this model does damage the dura mater. The relatively independent central environment is destroyed, clinically relevant, clinically similar quantifiable spinal cord injury models are difficult to replicate, and the mortality rate is high.