OBJECTIVE: To optimize the optimal experimental parameters for establishing a conditioned fear memory model in rats by using orthogonal experiments, and to find the optimal experimental conditions.
Methods: Using the principle of Pavlov's conditioned fear, a model of conditioned fear memory in rats was established; an orthogonal experimental design with 3 factors and 3 levels was used, and the stupor reaction time of rats 24 hours after the model was established was used as an index to observe fear under different parameter conditions. The optimal experimental conditions were determined based on the expression of memory. The conditioned fear memory model was established with the optimal experimental conditions, and the fear memory retention was tested after 24 hours, 1 week, 2 weeks, 4 weeks and 8 weeks.
Results: Intuitive analysis results showed that the influencing ability of each factor was sound intensity = number of cycles > electric shock intensity; variance analysis showed that the number of cycles had a significant impact on the experimental results (P < 0.05), while the impact of sound intensity and electric shock intensity was not significant (P < 0.05). P>0.05). The optimal experimental conditions were determined as follows: sound 75dB, electric shock 0.8mA, and 15 cycles. At 24h and 1 week after the model was established, the rats' fear memory kept well, and there was a significant difference compared with the control group (P<0.05). 0.001 and P<0.05); p="">0.05 after the second week).
Conclusion: This experiment clarified the priority of the influencing factors of the rat conditioned fear memory model, optimized the experimental conditions, and provided a reference for the standardization of the model and the follow-up research.