Method for constructing model of excessive compensation behavior of mice self-grooming and application thereof

Abstract

The application discloses a kind of based on mouse self-grooming overcompensation behavior model construction method and application, the method includes: the experimental mouse is randomly divided into blocking group and control group;Blocking group mouse wears blocking device to adapt, during adaptation, daily timing observation is carried out;Two groups of mice are equally fed in the form of single cage and single mouse for a set time, during which the blocking group mouse continues to wear blocking device, the weight of each mouse is measured and recorded every day;By comparing whether there is statistical difference in the weight change of two groups of mice, whether the wearing self-grooming blocking device has influence on the feeding and activity of mouse is judged;After removing the blocking device of blocking group mouse, record the self-grooming frequency and time of blocking group and control group in the same time period, compare whether there is difference in the results of two groups;Determine the overcompensation behavior model based on mouse self-grooming according to the judgment result and comparison result;Only by wearing annular blocking device, it is simple and easy to operate, and large-scale experiment can be carried out.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of neurobiology, and particularly relates to a method for constructing a model of over-compensation behavior based on self-grooming of mice. BACKGROUND

[0002] Self-defense mechanism is an unconscious psychological means formed by an individual to resist impulses from instincts and the anxiety induced thereby. Such instinctual impulses are generally caused by ideas unacceptable to the subconscious or desires that cannot be achieved under existing conditions. The self-defense mechanism enables the individual to temporarily cope with such stimuli and eliminate various anxieties to protect the self. Compensation is a type of self-defense mechanism, which is a strong intention to satisfy a certain demand in order to eliminate anxiety and protect the self when the individual cannot achieve the demand due to physiological and psychological defects. However, over-compensation can cause emotional imbalance: under the action of compensatory psychology / behavior, in order to pursue excessive satisfaction, the individual uncontrollably repeats a certain behavior beyond the self-bearing limit, which can lead to adverse effects or damage to the psychology / physique. For example, compulsive washing is a typical symptom of obsessive-compulsive disorder, which is specifically manifested in that the patient will perform high-frequency hand washing and bathing. Mild compulsive washing behavior generally does not cause damage to the patient's body, but if the external conditions change and the patient's washing desire and behavior cannot be satisfied, the patient's anxiety level will increase and the patient will perform "over-compensatory" (or retaliatory) washing after the event, thereby causing damage to the skin barrier and physical health. However, the individual has difficulty in controlling himself / herself to avoid such over-compensation behavior. Other common over-compensation behaviors such as "retaliatory sleep deprivation": because the individual's demand for controlling time during the day is not satisfied, the individual realizes this demand by occupying sleep time at night, which leads to sleep rhythm disorder. The high pressure and fast pace of modern work and life lead to frequent over-compensation behaviors, which cause the occurrence of emotional disturbance diseases. However, the neural mechanisms behind over-compensation behaviors are not clear. Therefore, establishing an animal model related to over-compensation behavior has important significance for studying the neural mechanisms behind it, understanding human social behavior, promoting social development, and improving the quality of people's life.

[0003] Mice have the following advantages as a model animal for neuroscience research: first, they are small mammals with short generation cycles, easy to raise, manage and breed; second, they are biologically close to humans. Placenta formation and early embryonic development are similar to humans, and cell function and tissue and organ structure are similar to humans. In addition, their advanced neural activity and various social attributes are highly similar to humans. Finally, the mouse genome sequencing project has been completed, and it has been found that 99% of human genes can be detected in mice, with a gene homology of 78.5%, and 93% of the regions have the same gene arrangement order. The technology for genome modification is mature. These characteristics make mice one of the ideal model animals for neuroscience research, and they are widely used in the study of various mental illnesses and psychological mechanisms.

[0004] Self-grooming behavior of mice is a common spontaneous behavior with multiple physiological functions such as body cleaning, awakening and stress relief. Self-grooming is one of the most common behaviors in awake rodents. However, self-grooming behavior may become pathological in some cases, such as excessive stress or certain mental illness factors, which can cause rodents to exhibit excessive self-grooming behavior. Therefore, the evaluation of animal self-grooming behavior has been widely used in neuroscience research. Excessive self-grooming behavior is related to conditions such as obsessive-compulsive disorder, autism and schizophrenia. When the normal self-grooming of mice is blocked, it will trigger significant overcompensation behavior, and even lead to the occurrence of anxiety-like behavior. SUMMARY

[0005] In order to solve the problems in the prior art, the application provides a method for constructing a mouse self-grooming overcompensation behavior model, which uses a simple experimental device and method to block the self-grooming of mice in a time-controllable manner, constructs an overcompensation behavior animal model, and simulates human overcompensation behavior well. It can be used to better understand the neural mechanisms of compensation behavior and improve its psychological theory; it can provide experimental evidence for new treatments for various diseases closely related to overcompensation behavior, such as bulimia, neurosis and obsessive-compulsive disorder; it is easy to operate and has little effect on the normal activity of mice, does not affect the vision, eating and movement of mice, causes little damage to the body, and meets the requirements of animal ethics.

[0006] In order to achieve the above purpose, the technical scheme adopted by the application is: a method for constructing a mouse self-grooming overcompensation behavior model, comprising the following steps:

[0007] Randomly divide the experimental mice into a blocking group and a control group;

[0008] The blocking group mice wear the blocking device for adaptation, and during the adaptation period, timed observation is performed every day to ensure that the blocking device can completely block the self-grooming behavior of the mice;

[0009] The two groups of mice are fed in a single cage and single mouse form for a set time, and during this period, the blocking group mice continue to wear the blocking device, and the body weight of each mouse is measured and recorded every day;

[0010] By comparing whether there is a statistical difference in the weight change of the two groups of mice, it is determined whether wearing the self-grooming blocking device has an impact on the food intake and activity of the mice;

[0011] After removing the blocking device of the blocking group mice, the self-grooming frequency and time of the blocking group and the control group in the same time period are recorded, and the results of the two groups are compared for differences;

[0012] According to the judgment result and the comparison result, a mouse self-grooming-based overcompensation behavior model is determined.

[0013] Further, the blocking device is a circular ring, the inner diameter d of the circular ring is C / π, C is the neck circumference of the mouse, and π is the circular constant, and the circular ring is provided with a separation opening in the radial direction.

[0014] Further, the circular ring is made of PVC soft plate.

[0015] Further, the mouse wearing the blocking device can move, stand, lie down, turn around, and climb freely.

[0016] Further, the adaptation period is at least 3 days, and the experimental period is at least 7 days.

[0017] Further, the health status of the mice is observed regularly during the adaptation period and the experimental period, and the neck of the mouse is checked for damage.

[0018] Further, based on image data, video recording equipment is used to record the behavior of the mice in real time to obtain image data.

[0019] Further, after the experimental period, the open field experiment, the elevated plus maze, the sugar water preference experiment, and the like are used to evaluate the changes in emotional behavior of the mice.

[0020] The application of the mouse self-grooming-based overcompensation behavior model obtained by the above model construction method is used to simulate human overcompensation behavior;

[0021] It is used to study the abnormal emotional disorder phenotype caused by breaking the stereotyped repetitive behavior in the model of mental illness;

[0022] It is combined with optical fiber recording, optogenetics or chemical genetics, two-photon method to study the neural circuit, cell type and related molecular mechanism of the compensation behavior of the mouse;

[0023] With the discovered molecular mechanism, new intervention strategies are sought, and the model is used to evaluate compensatory behavior treatment methods and targets.

[0024] Compared with the prior art, the present application has at least the following beneficial effects: it can be used for research on compensatory behavior and self-grooming behavior of mice; by wearing a ring-shaped blocking device, the self-grooming behavior of mice can be completely blocked, the operation is simple, large-scale experiments can be carried out, and it can be used for drug screening experiments; the entire experimental process is standardized, and there is a clear quantifiable judgment method for whether compensatory behavior occurs; only by blocking the self-grooming of mice can the related compensatory behavior be triggered, and it does not affect the normal activities such as eating and drinking of mice, has little damage to mice, and meets the requirements of animal ethics. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 Self-grooming behavior blocking device and device wearing schematic diagram.

[0026] Figure 2 Mouse wearing blocking device front view and side view.

[0027] Figure 3 Control group and experimental group experimental scene schematic diagram.

[0028] Figure 4 Experimental group and control group mouse weight change results. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0030] Reference Figure 1 and Figure 2 , Figure 1 In a, a is a blocking device schematic diagram, Figure 1 In b, b is a blocking device wearing schematic diagram, Figure 2 In a, a is a mouse wearing a blocking device front view, Figure 2Fig. 2b is a side view of a mouse wearing a blocking device; the device that blocks the mouse's self-grooming behavior is a soft circular ring structure, which aims to effectively block the mouse's forelimbs from self-grooming the head and face. The mouse's self-grooming behavior usually starts from the head and ends at the tail. The circular ring can effectively block the mouse's forelimbs from contacting the head and face, thereby breaking the normal sequence of the mouse's self-grooming. At the same time, the soft texture can minimize the discomfort that the mouse may feel from wearing the circular ring. The specific preparation method is as follows: cut a soft PVC material with a thickness of 0.8-1.2 mm into a circle with a diameter of 3.8-4.4 cm. Cut a concentric circle with a diameter of 1.3-1.5 cm in the middle of the circle, with the circle as the center. The specific size can be determined according to the measurement results of the mouse's neck circumference. Then, cut the circular ring at any position to obtain a broken end.

[0031] Model construction

[0032] Wearing a blocking device

[0033] Hold both ends of the circular ring blocking device with both hands, and apply force in opposite directions. Due to the good flexibility of the PVC material, the broken end of the circular ring can be separated but still maintain its structure. Align the separated ends through the mouse's neck and bond the broken ends with a 0.5 cm x 1 cm paper tape. After wearing, carefully observe the mouse's activity, including whether it can move freely, stand, lie down, turn around, or climb, to confirm that the circular ring does not hinder the mouse's free movement.

[0034] Adaptation and experimental stage

[0035] Reference Figure 3 , Figure 3 Fig. 2a is a schematic diagram of the experimental scene of the control group, Figure 3 Fig. 2b is a schematic diagram of the experimental scene of the experimental group. First, randomly divide the experimental mice into two groups: the blocking group and the control group. Make the mice in the blocking group wear the blocking device continuously for 3 days, 30 minutes a day. The purpose is to make the mice in the blocking group adapt to the presence of the blocking device and minimize the impact of the blocking device itself on the free movement of the mice in the blocking group. During the adaptation period, perform timed observations every day to ensure that the blocking device can completely block the mouse's self-grooming behavior.

[0036] Then, feed the two groups of mice in single cages with one mouse each (to avoid the mice relieving their self-grooming needs through mutual grooming) for 7 days. During this period, the mice in the blocking group continue to wear the blocking device. Measure and record the body weight of each mouse every day. By comparing the body weight changes of the two groups of mice, determine whether wearing the self-grooming blocking device has any impact on the mice's eating and activity. Note that during the wearing of the blocking device, the experimenter needs to observe the health status of the mice in the blocking group regularly and check whether the mouse's neck fur is worn or shed. If the mouse's neck fur is damaged, the neck circumference needs to be measured again and the inner diameter of the blocking device needs to be adjusted.

[0037] Compensation behavior evaluation phase

[0038] After the blocking device of the blocked group mice is removed, the number of self-grooming and the time of the blocked group and the control group are recorded in the same period, and the results of the two groups are compared. The open field test, elevated plus maze, sugar water preference test and other tests are used to evaluate the changes of emotional behavior of mice.

[0039] Select 20-25 gram, 4-8 week old male C57BL / 6 mice from C57BL / 6 mice. Experimental animal environment adaptation: before the experiment, the experimental mice were fed in single cages, and received at least 1 week of laboratory environment adaptation. During the adaptation period, the conditions of the mouse feeding (noise, light, temperature, humidity) were strictly controlled.

[0040] From 2 to 3 days before training, the operator gently holds (Handle) the mouse every day. And need to check the mouse state, record the initial weight of the mouse. Among them, handle the mouse is more important, requires the mouse to be not nervous in the operator's hand, and the state is relatively relaxed (can be judged by breathing rate, whether to shrink into a ball, whether to appear urine, etc.). After handle, the mice are sent back to the original feeding cage respectively.

[0041] Experimental animal grouping: 8 C57 mice were randomly divided into two groups, 4 of which were used as the blocked group, and 4 as the control group.

[0042] Measurement of mouse neck circumference: First, the blocked group mice were anesthetized with isoflurane, and the mouse neck circumference was measured with a 2 mm cotton thread. According to the neck circumference (C), the inner diameter of the blocked self-grooming behavior ring was determined. When measuring, the cotton thread should be in close contact with the mouse's neck skin without causing pressure.

[0043] Blocking device inner diameter (d) calculation: d = C / π, cut the PVC soft plate with a thickness of 0.1 cm into a circle with a diameter (d+2.7 cm±0.5 cm), and cut off a circle with a diameter of d in the middle with the circle as the center, to get a complete ring. At any position of the ring, it is disconnected to get an adjustable opening, which is convenient for wearing the blocking device;

[0044] After the blocked group C57 mice were anesthetized with isoflurane, they were placed on the experimental table, the blocking device was taken, and the two ends were held with both hands at the ring disconnection. In the opposite direction, gently force, due to the good flexibility of PVC material, the ring end can be separated but still maintain the structure intact; the separated opening is passed through the mouse's neck and matched with each other, and the end is bonded with 0.5 cm x 1 cm paper tape. After wearing, the mice are put back to the original cage for feeding.

[0045] Wear the blocking device to exclude the influence of the blocking device on the daily activities of the mice.

[0046] The blocking group mice wear the blocking device for 3 days, which is to adapt the mice to the presence of the blocking device. During the adaptation period, timed observation is performed every day to ensure that the annular blocking device completely blocks the self-grooming behavior of the mice. The two groups of mice are further fed in the form of single cage and single mouse for 7 days, during which the mice in the blocking group continue to wear the blocking device, and the body weight of each mouse is measured and recorded every day. By comparing whether there is a statistical difference in the body weight change of the two groups of mice, it is determined whether the wearing of the self-grooming blocking device has an effect on the food intake and activity of the mice.

[0047] Compensation behavior evaluation: mouse self-grooming behavior counting: after the blocking device worn by the mice in the blocking group is removed and the body weight measurement and recording are completed, the number of self-grooming times and the time of the blocking group and the control group in the same period are recorded respectively. By comparing the difference between the results of the two groups, the effect of the blocking device is evaluated.

[0048] Grooming count (30 min)

[0049]

[0050] Reference Figure 4 Body weight change (equal feeding)

[0051]

[0052] Based on the above data, the following results can be obtained: after wearing the blocking device, there is a statistical difference in the self-grooming behavior time of the mice in the control group and the blocking group, and the self-grooming time of the mice in the blocking group is obviously higher than that in the control group, which indicates that after wearing the blocking device, the mice appear self-grooming related compensation behavior. Under the condition that the mice in the blocking group wear the blocking device and the two groups are fed equally, there is no statistical difference in the body weight change of the mice in the control group and the blocking group within 7 days, which indicates that wearing the blocking device does not affect the food intake and normal activity of the mice.

[0053] Application based on the method of the present application:

[0054] (1) The method for blocking the self-grooming behavior of mice can be used to simulate the excessive compensation behavior of humans;

[0055] (2) It can be used to study the abnormal emotional disorder phenotype caused by the interruption of stereotyped repetitive behavior of autism mouse and other mental disease models;

[0056] (3) Combined with optical fiber recording, optical genetics or chemical genetics, two-photon and other methods, the neural circuit, cell type and related molecular mechanism of the compensation behavior of mice are studied;

[0057] (4) Using the discovered molecular mechanism to find new intervention strategies, combining the model to evaluate new methods and new targets for compensation behavior treatment.

Claims

1. A method for constructing a model based on excessive compensation behavior of mouse self-grooming, characterized by, The method comprises the following steps: Randomly divide the experimental mice into a blocking group and a control group; The mice in the blocking group wear the blocking device for adaptation, and during the adaptation period, the mice are observed at regular time points every day to ensure that the blocking device completely blocks the self-grooming behavior of the mice; The mice in the two groups are fed in the same way in a single cage for a certain period of time, and during the period, the mice in the blocking group continue to wear the blocking device, and the body weight of each mouse is measured and recorded every day; By comparing the body weight changes of the mice in the two groups, it is determined whether the wearing of the self-grooming blocking device affects the food intake and activity of the mice; After the blocking device of the mice in the blocking group is removed, the self-grooming frequency and time of the mice in the blocking group and the control group in the same period are recorded, and the results of the two groups are compared to determine whether there is a difference between the two groups; According to the judgment result and the comparison result, a mouse self-grooming-based overcompensation behavior model is determined.

2. The method for constructing an overcompensatory behavior model based on mouse self-grooming according to claim 1, characterized in that: The blocking device is a circular ring, the inner diameter d of the circular ring is C / π, C is the neck circumference of the mouse, and π is the circular constant, and the circular ring is provided with a separation opening in the radial direction.

3. The method for constructing an overcompensation behavior model based on mouse self-grooming according to claim 1, characterized in that: The circular ring is made of PVC soft plate.

4. The method for constructing an overcompensatory behavior model based on mouse self-grooming according to claim 1, characterized in that: The mouse wearing the blocking device can move, stand, lie down, turn around and climb freely.

5. The method for constructing an overcompensatory behavior model based on mouse self-grooming according to claim 1, characterized in that: The adaptation period is at least 3 days, and the experimental period is at least 7 days.

6. The method for constructing an overcompensation behavior model based on mouse self-grooming according to claim 1, characterized in that: During the adaptation period and the experimental period, the health status of the mice is observed regularly, and whether the neck of the mouse is damaged is checked.

7. The method for constructing an overcompensatory behavior model based on mouse self-grooming according to claim 1, wherein: The mice are observed at regular time points every day based on image data, and the behavior of the mice is recorded in real time by using a video recording device to obtain image data.

8. The method for constructing an overcompensatory behavior model based on mouse self-grooming according to claim 1, wherein: After the experimental period ends, the open field experiment, the elevated plus maze or the sugar water preference experiment is used to evaluate the change of the emotional behavior of the mouse.

9. Use of a model based on the overcompensation of the self-grooming behavior of mice obtained by the method according to any one of claims 1 to 8, characterized in that, The method is used for simulating human overcompensation behavior; The method is used for studying abnormal emotional disorder phenotypes caused by breaking of stereotyped repetitive behavior under a mental illness model; The method is used for studying the neural circuit, cell type and related molecular mechanism of the compensation behavior of the mouse by combining fiber recording, optogenetics or chemical genetics and two-photon method; The method is used for finding new intervention strategies and evaluating compensation behavior treatment methods and targets by combining the discovered molecular mechanism and the model.

Images