How to prepare convulsive animal model?

  (1) Pentylenetetrazol-induced seizure model

  1. Modeling materials Animals: Kunming mice, weighing 18-22g, both male and female, or rats; drug: penetrazole (PTZ).

  2. Modeling method Model mice were injected intraperitoneally with pentylenetetrazol 90mg/kg. The control group was injected with the same amount of saline. Or intramuscular injection of pentylenetetrazol 112mg/kg, or subcutaneous injection of 110mg/kg, taking systemic clonic convulsion as an indicator, generally observe 60min after giving pentylenetetrazol.

  3. Principle of Modeling Pentylenetetrazol mainly acts on the brainstem and brain, enhancing the facilitating process of excitatory synapses and causing convulsions. At the threshold dose, it can cause clonic convulsions in animals and is a commonly used convulsant.

  4. Changes after modeling. Hindlimb extension is used as an indicator. Convulsions (grand seizures) can be observed in mice, and the clonic latency is (17.3±7.6)s.

  5. Precautions This experiment is related to animal strains. The mortality rate of mice of different strains after continuous convulsions is quite different, so attention should be paid to the experiment; some animals may have tonic convulsions or even death after clonic convulsions.

  (2) Pentylenetetrazol Chronic Kindling Rat Convulsion Model

  1. Modeling materials Animals: SD male rats, weighing (200±20) g; drug: pentylenetetrazol.

  2. Modeling method SD male rats, weighing (200±20) g, were intraperitoneally injected with PTZ 35mg/kg every other day for 28 days. After stopping the drug for 1 week, test with the same dose of PTZ.

  3. Principles of Modeling Pentylenetetrazole excites the lip-side area of the brainstem and the brain, causing animal convulsions.

  4. Changes after modeling After modeling, all rats that showed 5 consecutive convulsions above grade 2 were ignited rats. Scoring criteria for convulsive behavior in rats: Grade 0, no behavioral seizures; Grade 1, rhythmic nodding or head twitch; Grade 2, clonic chewing; Grade 3, head twitch plus forelimb clonic twitch; Level 4, kangaroo posture (upright upright); level 5, fall; level 6, tonic convulsion.

  (3) Strychnine induced convulsions in mice

  1. Modeling materials Animals: Kunming mice, weighing 18-22g, for both sexes; drug: Strychnine nitrate injection.

  2. Modeling method Model mice were injected intraperitoneally with 1.5 mg/kg strychnine nitrate injection. The control group was injected with the same amount of saline.

  3. Principles of Modeling Strychnine is an antagonist of spinal cord inhibitory neuron glycine receptors, which can selectively excite the spinal cord, and large doses of intraperitoneal injection can cause animals to produce epileptic-like tonic convulsions.

  4. Changes after modeling After modeling, it was observed that the mice had tonic convulsions. The incubation period was (5.1±1.0) min, the convulsion rate was 100%, the death time was (6.8±2.6) min, and the mortality rate was 100%.

  (4) Electrical stimulation leads to convulsions in mice

  1. Modeling materials Animals: Kunming mice, weighing 18-22g, for both males and females; Apparatus: YSD-5 multi-purpose instrument for pharmacological and physiological experiments.

  2. Modeling method Take mice with YSD-5 pharmacological and physiological experiment multi-purpose instrument for electrical stimulation. Stimulation method: single; interval: 300ms; voltage adjustment knob is fixed at 7.5 grids (100V). Tonic convulsions on hind limbs are qualified.

  3. Principles of Modeling Electrical stimulation caused convulsions in mice.

  4. Changes after model building Animals developed tonic convulsions after electrical stimulation.

  (5) Developmental rat model of febrile convulsion

  1. Modeling materials Animals: 21-day-old SD rats, weighing 60-100 g, for both sexes; equipment: hot water bath.

  2. Modeling method The water depth in the hot water bath (44.5°C) is based on the rat's head being exposed when standing along the wall of the box. The rat will be taken out if there is no seizure in the water for 5 minutes, and the seizure will start if the seizure occurs within 5 minutes. Take it out from time to time. Convulsions were induced once every other day for a total of 10 times. The rats were sacrificed 24 hours after the last induction.

  3. Principles of Modeling A hot water bath is used to induce febrile convulsions in rats.

  4. Changes after modeling. HE staining results: The cells in the CA1 and CA2 areas of the hippocampus of the normal control group are arranged neatly, extremely well, uniformly stained, and the nuclei are uniform in size and oblong. The cells in the CA1 and CA2 regions of the hippocampus of the model rats are arranged disorderly, polar orientation is not clear, the cells are vacuolated, and the nuclei are inconsistent in size, round or oval.

  The ultrastructural changes of the neurons in the hippocampal CA1 and hilar areas of rats: the normal control group rat hippocampal CA1 and hilar neurons have regular cells, uniform matrix, oval-shaped mitochondria, normal size, regular cristae, and rough endoplasmic reticulum The structure of the ribosome is clear, the nuclear membrane is smooth, the nucleus is round, the autosomes are evenly distributed, and the nucleolus is clear. The mitochondria of hippocampal CA1 and hilar neurons in the model rats are small in size, the matrix is concentrated, the cristae is blurred, or even disappeared, and some mitochondria appear vacuoles and deformities, and the Golgi complex is slightly to moderately expanded and the structure is unclear.

  (6) Auditory convulsion model

  1. Modeling materials Animals: rats, both male and female; equipment: soundproof box, electric bell.

  2. Modeling method Select rats that are sensitive to auditory seizures, and those who can produce running or convulsions with electric bell stimulation for 60s (or 90s) are the experimental subjects. From now on, stimulate once a day under the same conditions for 3 to 5 consecutive days, with a constant response as a model for experiments.

  3. Principle of Modeling Strong ringing stimulation causes the auditory center to be over-excited, and then spreads to the neighboring motor centers, causing certain sensitive animals to produce a stereotyped motor seizure.

  4. Changes after model building Animals convulsed when stimulated by electric bell.

  5. Precautions Before the experiment, the test rats should be screened for their responsiveness to the ringtone. The experimental conditions must be strictly controlled, and the control conditions should be the same for each stimulation.

  (VII) Semicarbazide-induced convulsions in mice

  1. Modeling materials Animals: Kunming mice, body weight (22±2) g, both male and female; drug: semicarbazide.

  2. Modeling method 150mg/kg semicarbazide was injected into the tail vein, the injection volume was 0.01ml/g, and the injection time was 8s. Convulsive seizures are caused by running wildly and stiff hind limbs.

  3. Modeling principle Thiosemicarbazide is an inhibitor of glutamate decarboxylase, which inhibits the production of γ-aminobutyric acid (gam-ma-aminobutyric acid, GABA) from glutamate, reduces the synthesis of GABA and reduces the level of GABA in the brain. Cause convulsions.

  4. Changes after modeling After injection, the modeled animals showed rushing and stiff hind limbs, the incubation period was (49.3±11.6) min, and the survival time was (59.3±23.4) min.