动物造模,药效评价,外伤性癫痫 z-bio 2024-08-06 284

　　1. Modeling material animals: Healthy adult male SD rats weighing 180-220g; Drug: 10% chloral hydrate, FeCl2 solution.

　　2. Modeling method: Rats were anesthetized intraperitoneally with 10% chloral hydrate (350mg/kg). Fixed on the stereotactic frame. Surgical exposure of the skull and determination of the drilling site based on the injection site. Drill open the skull and, according to the stereotaxic map of the rat brain by Bao Xinmin et al. (1991), slowly inject a microsampler into the target site (coordinates of the right frontal cortex of the rat: 2.0mm anterior fontanelle, 3.0mm midline, and 2.0mm subdural). Drill a hole on the right forehead and right pillow to install stainless steel electrodes and fix them. Place the reference electrode on the right ear. Connect to POWERLAB physiological recorder. Start recording the electroencephalogram, and after 10 minutes, slowly inject 1000nmol FeCl2 (0.1mol/L) into the target using an automatic thruster at a rate of 1 μ l/min. After injection, leave the needle for 5 minutes. The sham surgery control group was injected with an equal amount of physiological saline at the same site.

　　3. The principle of modeling is that iron has an epileptic effect.

　　4. Changes after modeling: After successful injection of FeCl2, the rats showed staring and immobility in a paroxysmal manner, followed by wet dog like movements. Or automatic symptoms may occur. Repeatedly nodding, chewing, yawning, sneezing, etc., accompanied by facial twitching and mild convulsions, with tremors in one forelimb: standing, tremors in both forelimbs, and persistent nodding; The tremors in both forelimbs have worsened. Loss of balance leading to generalized tonic clonic seizures; Severe cases may result in exhaustion leading to death.

　　The disease course of the model group is clearly divided into acute phase, quiescent phase, and chronic phase. Frequent attacks occur within 7 days, especially within 3 days, followed by a decrease in attacks. After 15 days, more regular attacks appear, with focal attacks being more common.

　　The EEG frequency of normal rats is mainly between 5-10Hz, with an amplitude of less than 200V. Mainly low amplitude β and α, scattered in θ waves. After injection of physiological saline, there was no significant change in EEG waveform. After injecting the cortex into the model group, there was an average latency of (60+18) seconds, and the EEG of rats showed various forms of epileptic like discharge waveforms. Typical waveforms include single spike waves, multiple spike waves, multi-phase spike waves, biphasic spike waves, positive spike waves, spike rhythms, slow waves, spike slow waves, slow wave superimposed spike rhythms, sharp waves, episodic rhythmic waves, and post attack suppression. The fastest frequency can reach 30Hz. The wave amplitude can reach up to 310V, and inhibitory waves may appear after the attack.

　　5. Pathological changes after modeling: The general appearance of the model group showed atrophy of the right frontal lobe. Obvious brownish yellow color, indicating deposition of hemosiderin, while no significant changes were observed in the corresponding parts of the control group. Observation under light microscope: The injection site of the model group showed obvious neuronal degeneration and death, as well as cellular structure disintegration and disorder. There is a significant loss of hippocampal neurons on the experimental side, with the most obvious loss in the CA3 area. Neurons in the CA3 and CA4 areas of the hippocampus on the experimental side are missing, with nuclear condensation, staining, appearance of eosinophilic neurons, and disordered cell arrangement; Glial cell proliferation. Control side is mild; CA1 and CA2 lesions are mild. The model group showed significantly lower cell density in the cerebral cortex and hippocampal CA1 and CA3 regions compared to the control group. There is a large infiltration of Perls positive phagocytic cells in and around the injection site of the model group, with phagocytic cells occupying almost the entire lesion. Macrophages are deeply stained in the periphery, and under light microscopy, the cytoplasm particles are coarse and accumulate in large quantities, making it difficult to distinguish between cytoplasm and nucleus. Small phagocytic cells and a small number of macrophages are located in the center of the lesion and are also stained dark blue. The glial cell response around the lesion is also enhanced, with cell bodies that are elongated or tadpole shaped, with varying lengths of protrusions. There are a large number of cells, all stained dark blue, with cytoplasm and protrusions stained, and nuclei not stained. The control group showed negative Peds reaction in the prefrontal cortex, or only sparse macrophage deep staining within the lesion. The scattered microglia cells near the lesion on the injured side were Perls positive, while other areas were close to normal.

　　6. Precautions: Surgical instruments should be strictly disinfected to prevent surgical infections, surgical trauma should be minimized, and aseptic operation should be strictly followed; When drilling a skull, attention should be paid to the depth. Once there is a sense of breakthrough, stop immediately to prevent excessive bleeding.

　　After surgery, rats should be separated and housed in cages 3-5 hours after awakening to prevent the first waking rats from licking and biting the wounds of comatose rats. Try to maintain the optimal temperature and humidity for rats in the breeding room as much as possible.