动物造模,药效评价,剥夺性弱视 z-bio 2024-07-24 394

　　Although the visual system of rats is not as close to humans as that of monkeys and cats, they still have a certain stereoscopic vision range, and their visual development is 2-3 times faster than that of cats. The sensitive period for their visual development is 2-8 weeks of age. Rats are inexpensive, easy to raise, and the selection of animals can be standardized to reduce errors. Therefore, rats are currently the most widely used experimental animals for visual development research, especially for the study of the visual center.

　　The amblyopia model in rats can be established using Wista rats or SD rats, usually 2-week-old rats. The selected rats were anesthetized by intraperitoneal injection of 10% chloral hydrate or ether at a dose of 0.2ml/kg body weight. 0.3% iodine was used to strictly disinfect the eyelids of the rats to be operated on. The upper and lower eyelid margins were cut off by 1.5-2.0mm, and the eyelid margins were well aligned. Then, the subcutaneous and skin tissues were sutured with 5-0 silk thread layer by layer for 2-3 needles to close the operated eye. It is also possible to directly suture the experimental eyes of rats. Administer intraperitoneal injection of 100000 U/kg penicillin within 3 days after surgery to prevent infection. Disinfect and inspect the wound daily within 1 week to avoid infection and suture detachment. Keep under natural light for 4 weeks, but the daily exposure time should not be less than 12 hours. After one month, a rat model of deprivation amblyopia can be successfully established. When special experimental requirements arise, visual deprivation surgery can also be performed on the third day after the birth of young mice.

　　After 4 weeks, all modeling rats underwent VEP testing to determine the modeling status. First, cut open the eyelids of the model rats with form deprivation and eye adhesion, fully expose the cornea of the eyeball, and place them in a dark room together with the normal group rats for 30 minutes. Anesthetize them by intraperitoneal injection of 10% chloral hydrate at a dose of 0.3ml/kg body weight. Drip Meiduoli eye drops into the conjunctival sac of both eyes to disperse the large pupils, and cut off the body hair at the corresponding visual cortex areas of the rat's anterior fontanelle, bilateral mastoid, and bilateral posterior ends of the head. Place the rats on a fixed device and test the P-VEP of the experimental group rats in the form deprivation model eye and the non model eye separately. When checking one eye, cover the other eye with an opaque black eye mask. Adjust the subject's eye to align the center of the retina with the central visual target, with the corneal vertex 25cm away from the screen. Using a chessboard pattern flipping stimulus. The average brightness is 50cd/m2, the area is equivalent to a viewing angle of 120 × 120, the spatial frequency is 0.16cpd, the temporal frequency is 1Hz, the contrast is 60%, the bandpass is 0.5-100Hz, and the impedance is less than 2k Ω after 100 repetitions.