【Abstract】 Objective To determine the effect of prolonging the exposure time of post-traumatic shaving environment on the expression of conditional fear in a single clue. Method Light cues conditional fear training prolongs the animal's residence time in the training environment. Results Prolonging the exposure time after trauma can eliminate the animal's fear of the environment and prevent it from recovering spontaneously. And thus inhibited the conditional fear response to a single clue, mainly in the traumatic environment, the conditional fear response of the exposed group of animals to the light cues was lower than that of the non-extended exposure group [fear level was (19.531 ± 6) .073)%, (46.094±10.427)%], reached a marginal level (P=0.085), and this fear downregulation can last for at least 35 days [prolonged fear levels in exposed and non-extended exposure groups) They were (21.094 soil 4.897)%, (74.219±9.481)%, and corpse <0.01].

【in conclusion】
Extending the exposure time of the wound environment changes the “fear” characterization of the traumatic environment, thereby making the traumatic environment a “safe scene setter” that reduces the expression of conditional fear of a single clue, suggesting that the traumatic environment stays longer after trauma. The victim’s fear of the environment disappears and may help prevent the development of post-traumatic stress disorder.

【Key words】 Environmental exposure; Environmental conditional fear; Single clue conditional fear; Scene setting; Post-traumatic stress disorder

[1. Materials]
1. Animals: 16 male SD rats, initial mean body mass (280 ± 10) g. Animals were housed in 50.0 cm × 22.5 cm × 30.0em stainless steel cages, 4 per cage, free to enter the water. The photoperiod is from 7:00 to 19:00, the feeding environment temperature is 22 to 24 ° C, and the relative humidity is 40% to 60%. Before the start of the formal experiment, the adaptive feeding was carried out for one week, and the rats were touched every day during the adaptation period to adapt to the operation of the main test personnel. All procedures in this experiment were approved by the Ethics Committee of the Institute of Psychology of the Chinese Academy of Sciences.
2. Equipment: The experimental equipment is 2 different boxes. Skinner's operational conditional reflection box (30cm × 21cm × 30cm cuboid box, produced by American company Med) is used for conditional fear training and traumatic environment fear memory test. The front and rear walls are made of transparent plexiglass, and the left and right sides are made of aluminum. On the side wall, the conditional clue signal is emitted by two stimuli lamps on the upper side of the right side wall. The bottom plate is made up of 18 stainless steel strips. Each stainless steel strip has a diameter of 0.6 cm and a center interval of 1.5 cm. It can pass a computer-controlled current. The Skinner box is placed in a soundproofed outer box, the fan on the side wall of the outer box emits about 65dB of noise, and a red 25w bulb is used as ambient lighting. The Spontaneous Motion Test Box is a 35cm x 35cm x 50cm black plexiglass cuboid box with a stimulating lamp on one side wall to provide conditional clues. The background illumination is provided by a 15w yellow bulb that provides non-invasive conditions for conditional fear memory testing. surroundings. During the experiment, the Skinner box was cleaned with 75% alcohol and the spontaneous sports box was cleaned with detergent to make the two environments completely different.
[two, method]
1. Conditional Fear Training and Environmental Exposure: On the first day after the end of the 1-week acclimation period, the rats were placed in a Skinner box and spontaneous exercise test kits for 5 min each for adaptation. On the second day, conditional fear training was conducted. During the training, the rats were placed in the Skinner box, and 3rain was given for adaptation. After 3rain, 15 lights were given (continued 8S, CS)-electric shock (0.8mA, lasting 1S, us). Matching training, the light and the electric shock are simultaneously ended, and the interval of each matching presentation is 60S. After the last match was presented, the rats were divided into 2 groups according to the time when the rats were taken out, one group was taken 2 min after the last matching presentation (non-extended exposure group), and one group was taken out after 90rain (extended exposure group).
2. Fear conditioning test (test a): After the fear conditioning training days 2 fear memory test, the test environment are respectively wound environment (Skinner box) and non-traumatic environment (locomotor test box), the first non- Wound environment test. During the test, the 3rain environment was exposed first, and after 3rain, 2 lights were given. Without electric shock, each time the light lasted 8S, 2 times interval 60S, and the rats were taken out 2rain after the last light. A traumatic environment test was performed after the non-traumatic environmental test. 2 in rats by the previous exposure of the training environment at different times, and therefore on the environment have different fear reactions, the reaction to this fear extinction, let 2 rats exposed to wound environment 60min. The 60rain environment exposure was carried out in 3 time periods, each with 20rain and 2rain. After the last 20rain exposure, 2rain, formal conditional fear test, the test procedure is the same as the non-traumatic environment test.
3. Conditional Fear Memory Spontaneous Recovery Test (Test 2): After 35 days of testing, the animals were again tested for fear responses in the trauma training environment and the non-traumatic environment. The test sequences of the two groups of animals were balanced in two environments, and half of them were first tested in the wound environment. Generally, they were first tested in a non-invasive environment, and the test procedure was the same as above. The behavior of the rats during the entire behavioral procedure was recorded and saved. The animal's fear behavior is recorded by the stopwatch, which shows that there is no action other than the life-sustaining breath, the so-called "freez.ing behavior". The ordinates in all figures in this study are the percentage of time during which the animal's "stiffness" behavior is the total test period, ie the level of fear in the animal.

4. Statistical data: Conditional fear training was performed by one-way repeated measures analysis of variance for statistical analysis. Environmental and light cues conditional fear was statistically analyzed by t-test and 2×2 two-way analysis of variance. Two of the environmental conditional fear tests were used. The factors were intra-group factor test (test 1, test 2) and inter-group factors (extended exposure group, non-extended exposure group). Two factors in the conditional fear test of light cues were the intra-group factors environment (trauma environment). , non-traumatic environment) and group factors (extended exposure group, non-extended exposure group). All data is done by the SPSS12.0 forwindows statistical package.

【result】
1. Immediately after trauma, the effect of traumatic environmental exposure on the expression of environmental conditional fear memory is different. The difference between the extended exposure group and the extended exposure group is that the time of staying in the original training environment after conditional fear training is different, and the exposure time of the environment is prolonged. Significantly reduced the animal's fear response to the original traumatic environment (data not shown). Environmental Conditional Fear measures the level of fear in the first 3rain and the last 3 after the 60rain exposure in the shaved environment, and the level of fear 3 minutes before the light lead before the two tests . As can be seen from Fig. la, the two groups of animals obtained the same level of conditional fear of the environment. After the 1h traumatic environment exposure on the 2nd day after training, the fear response of the two groups of animals to the environment basically disappeared (ie, the level after the regression), and the subsequent test 1 also showed the same level of environmental fear between the two groups. However, in the spontaneous recovery test of environmental conditional fear (Fig. 1b), the analysis of variance showed that the main effect of the test was significant (F(1. Ge)=9. (136, P 0.05).

Ultrasonic textile Machine

Our company is specialized in development of ultrasonic technology and Automatic equipments. Our team has more than 10 years of professional experience of technology and practical in ultrasonic area. With the core concept of"improve Huitong person abilities in practices and communications to create the classic brand in one century generations to generations through our professional level and Unremitting efforts, to provide the province of artificial, efficient and stable automatic production equipment. Since its inception we have been adhering to the user needs as the core, more than 30 countries and regions we proving quality and stability of the equipment for customer and after-sales service intentions, won many enterprises trust and praise.