【Animal Modeling】-Indirect optic nerve injury model

  (1) Reproduction method Pentobarbital sodium was injected via ear vein at a dose of 30 mg/kg body weight to anesthetize New Zealand rabbits weighing 2.0 to 2.5 kg. After fixing the animal, fix the rail notch and rail wall on both sides. Bone forceps bite the orbital wall (depth 7-8 mm, width 6 mm), put the head under the wound tube, clamp the homemade wound on the orbital plate above the orbital nerve foramen, the wound balloon (45 g) wound from The top of the tube (tube length 2 m) falls freely, hits the injured chuck, and transmits the force through the orbit to the orbital foramen, thereby damaging the nerve. When the light reflection disappears, the damage is successful.

  (2) A feature of the model is that certain areas of the optic nerve tissue show demyelination changes, the tissue is loose and reticulated, and some axons are exposed. There is cell infiltration in the nerve papilla, and the distribution of glial cells is uneven. Nerve fibers are loose, myelin sheath usually degenerates, mitochondria are swollen and severely vacuolated. Part of the degenerated myelin sheath forms an onion-like body, softened areas of glial and local edema.

  (3) In comparison clinics, the most common optic nerve injury is the conduction of trauma through the skull. It can cause optic nerve damage, with or without optic canal fracture. However, the closed blow molding method to model the optic nerve injury is in line with the characteristics of clinical optic nerve injury, but the disadvantage is that the success rate is low and the mortality rate is high. It is an ideal choice for modeling. This model method uses an open blow to bite part of the track wall first, so the blow is more concentrated and the direction is clearer. It has low damage intensity, and can stably and effectively cause optic nerve damage. Compared with other optic nerve injury models, it is closer to the clinical indirect optic nerve. Damage characteristics. In addition, the afferent pupillary light reflection abnormality can be used as a simple marker to determine the optic nerve damage in animals.