【Animal Experiment】-The influence of acute psychological stress of electric shock on the learning and memory ability of animals

  A lot of evidence shows that chronic psychological stress can damage the spatial memory of animals, and this damage involves changes in the hippocampus structure of animals. However, the effect of acute psychological stress on memory is still controversial. Most literature believes that acute psychological stress can damage the spatial memory of animals. But there are also some reports in the literature that acute psychological stress can improve the spatial memory of animals. Moreover, the current researches on acute psychological stress and memory barriers mostly focus on the process of memory formation, while less involved in other aspects of memory. To understand the relationship between acute psychological stress and animal spatial memory, a bystander electric shock stress mouse model was used to observe the performance of mice in the Barnes maze to explore the relationship between acute psychological stress and animal spatial memory.

  Watch the electric shock experiment plan

  The experiment uses the acquired helpless system (transparent box version), the mice that are shocked (the shock current is set to 0.2-0.5m A random, the time of each shock is 1s-5s random, and the intermittent duration of the shock is 1min-5min random, The purpose of randomization is to prevent animals from finding patterns). Electric shocks cause animals to scream, startle and even incontinence; mice in the experimental stress group are not exposed to electric shocks, but to observe the process of electric shock mice receiving electric shocks through vision and hearing And so on and produce psychological stress. Each stress is carried out in batches from 9:00 to 11:00, each batch lasts for 1h, once a day, for a total of 2 days. During the stress period, the rats are also given half the amount of food to ensure subsequent behavior The mice remained hungry during the test. The mice in the control group were placed in the same box, but no bystander electrical stimulation was applied.

  Barnes Labyrinth Behavior Test:

  Barnes labyrinth experiment system is designed by using rodents’ habit of liking darkness and avoiding light. Through strong light irradiation and noise stimulation, animals are forced to find a dark box under a hole at a specified location within a specified time. The experiment is divided into a training period and a test period. After a few days of continuous training, the test will record the time, total distance, speed, etc. of the animal entering the dark box, as well as the number of times the animal enters the wrong hole to reflect the animal's spatial reference memory ability. It can also be repeated by recording the animal. The number of wrong holes is used to measure the animal’s working memory. Note: Rotate the maze randomly after each training to ensure that the maze position is different for two consecutive days, but the target box position does not change. When an animal wanders around other caves, its head sticks into the cave and its eyes are below the edge of the platform, it is judged as an escape error.

  ①Learning process: At the beginning of each training, place the mouse in the center of the maze, freely choose to enter each hole to find food, each training 6 minutes or complete foraging ahead of time, that is, the end of training. After each mouse is done, wipe the maze with alcohol and rotate the Barnes maze, but the relative spatial position of the target hole is not changed to prevent the mouse from using information such as smell to find food. Train once every morning for a total of 8 days.

  ②Test process: After the psychological stress is done, the mice are subjected to the Barnes maze behavior test at an interval of 10 minutes. The test method is the same as the learning phase. The Barnes maze reflects the animal's spatial reference memory.