A two-dimensional objective detection device and method for quantifying subjective emotions of mice

Abstract

The application discloses a two-dimensional objective detection device and method for quantifying subjective emotion of mice, which comprises a box body, the periphery and top of the box body are made of black acrylic material, the bottom is made of transparent material, the box body is sequentially provided with a runway A, a chamber a, a runway B and a chamber b along the length direction, beam type pressure sensors are arranged at the bottom of the runway A and the runway B and used for monitoring the walking speed, ground touch speed and ground touch pressure parameters of the mice in the runway; the probability of the mice obtaining food in the first chamber is changed, the walking speed, ground touch speed and ground touch pressure parameters of the mice in the runway are monitored, the emotional experience of the mice on the second runway is obtained according to the monitoring result, a fast and simple behavior paradigm is adopted to detect the subjective emotional experience of the mice in two dimensions, the emotional experience of the mice is more accurately measured in the dimensions of happiness and unhappiness and the degree of awakening, and a new idea is provided for the research on emotional and affective disorders in mental diseases.

Description

Technical Field

[0001] This invention belongs to the field of neurobiology, specifically relating to a two-dimensional objective detection device and method for quantifying subjective emotions in mice. Background Technology

[0002] Emotion is a subjective experience and accompanying behavioral response in humans or other animals to stimuli or stimuli. Meeting an individual's needs and desires evokes positive, affirmative emotions, while the opposite evokes negative, detrimental emotions. Emotions play a crucial role in animal survival and development, and many mental illnesses are often accompanied by mood disorders. Therefore, the measurement of emotion has always been a focus of attention. Currently, some relatively effective emotion measurement index systems have been preliminarily established for humans, capable of measuring internal subjective experiences, external behavioral manifestations, and internal physiological changes. However, due to ethical and technical limitations, research on the working principles of emotion and the neural mechanisms of mood disorders currently relies heavily on animal models. In animal experiments, since animals cannot express their subjective experiences verbally, their emotional state is mainly assessed indirectly by measuring their external behavioral manifestations and physiological changes. For example, the conflict between a small animal's desire to explore new spaces and its natural instinct to avoid exposure to open, bright places is used to detect anxiety in mice using open fields and cruciform straddles. However, existing methods for detecting emotional states in mice can only detect negative emotions such as anxiety and depression; effective methods for detecting positive emotions and more complex emotions are lacking. Meanwhile, open fields and elevated mazes rely on mice's desire to explore new spaces, which is not reproducible in the short term and is not feasible for some experiments that require repeated testing of emotions. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a two-dimensional objective detection method for quantifying subjective emotions in mice. It employs a quick and simple behavioral paradigm to detect transient subjective emotional experiences in mice across two dimensions, providing more accurate measurements of emotional experiences in mice across the dimensions of pleasure and unpleasantness and the degree of arousal. This offers new insights for the study of emotional disorders in mental illnesses.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a two-dimensional objective detection device for quantifying the subjective emotions of mice, comprising a box, the sides and top of which are made of black acrylic material, and the bottom of which is made of transparent material. The box is provided with a track A, a chamber a, a track B and a chamber b in sequence along its length. Beam-type pressure sensors are installed at the bottom of track A and track B to monitor the walking speed, ground contact speed and ground contact pressure parameters of the mice on the track.

[0005] This invention also provides a two-dimensional objective detection method for quantifying subjective emotions in mice, based on the two-dimensional objective detection device for quantifying subjective emotions in mice, comprising the following processes:

[0006] Food restriction phase: The experimental mice were housed individually in cages, with food restricted but water not. The weight of the mice was recorded daily and kept at 80% to 90% of their original weight.

[0007] Training phase: Mice were trained to run from track A to chamber a, where they received a food reward, and then run from track B to chamber b, where they received another food reward. This training was repeated until the mice's running speed gradually stabilized. At the same time, the mice's walking speed, ground contact speed, and ground contact pressure parameters on the track were extracted as baselines.

[0008] Testing phase: By changing the probability of mice obtaining food in the first chamber, the emotional experience of mice on the second track was monitored, along with the walking speed, ground contact speed, and ground contact pressure parameters of the mice on the track.

[0009] The emotional experience of mice was assessed on the pleasure and arousal dimensions. The calculation formulas are as follows:

[0010] Pleasure Dimension Index H = (Touch Speed ​​ / Touch Pressure) Test / (Touch Speed ​​ / Touch Pressure) Baseline

[0011] H>1 indicates that the mouse has a pleasant emotional experience, H<1 indicates that the mouse has an unpleasant emotional experience, and H=1 indicates that the mouse has no emotional change. The larger the H value, the more pleasant the emotional experience of the mouse.

[0012] Arousal Dimension Index W = (Runway Walking Speed) Test / (Runway Walking Speed) Baseline

[0013] W>1 indicates that the mouse experiences excitement, W<1 indicates that the mouse experiences calmness, and W=1 indicates that the mouse has no emotional change. The larger the W value, the higher the arousal level of the mouse's emotional experience.

[0014] Interpretation of the emotional dimension: If the H value of the mouse is less than 1 and the W value is greater than 1, it indicates that the mouse is in the anger emotional dimension; if the H value is greater than 1 and the W value is greater than 1, it indicates that the mouse is in the joy emotional dimension; if the H value is less than 1 and the W value is less than 1, the mouse may be in the depression emotional dimension.

[0015] The first three days of the experiment were a restricted feeding period. The mice were fed small amounts of rat food and sugar pills at 8:00 am and 8:00 pm every day to keep their weight at 80%-90% of the baseline level. Their weight was measured every day during the entire behavioral testing period thereafter to keep them in a state of hunger.

[0016] On the first day of the training phase, three sugar pills were placed in chamber a and chamber b respectively. The mouse was gently placed at the starting point of track A and allowed to explore freely, run to chamber a, find and eat the sugar pill, and then run through chamber a into track B to find and eat the sugar pill. The above steps were repeated 10 times a day for 3 consecutive days until the mouse’s speed on the track stabilized.

[0017] (3) When testing pleasant emotional experiences, 8 sugar pills were placed in chamber a and 3 sugar pills were placed in chamber b; when testing unpleasant emotional experiences, 3 sugar pills were placed in chamber a with a 50% probability and 3 sugar pills were placed in chamber b. After obtaining the speed, ground contact speed and ground contact pressure parameters of the mice on the track, the pleasant dimension index H = (ground contact speed / ground contact pressure) test / (ground contact speed / ground contact pressure) baseline and the arousal dimension index W = (track walking speed) test / (track walking speed) baseline were calculated.

[0018] During both the training and testing phases, the sidewalls of the runway were wiped with 75% alcohol, and the sidewalls of the feeding chambers were wiped with 1% acetic acid.

[0019] During the initial training, if the mouse stays in any place in the sequence of track A-chamber a-track B for more than 5 minutes without entering the next space, gently push the mouse from the hole into the next space using a plastic board.

[0020] During the training phase, if a mouse fails to advance to the next step within 5 minutes for a cumulative total of 10 attempts (5 consecutive attempts), it will be eliminated.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] This invention provides an apparatus and method for detecting transient emotional experiences in mice. Previous methods for detecting mouse emotions were primarily used for qualitative detection of inherent, persistent emotional states. This invention overcomes the limitation of failing to detect transient emotional experiences. This invention allows for testing mouse emotional experiences with minimal stress. It enables repeated measurements within a short period. The subjective emotional experiences triggered during the testing process are all transient, with no significant subsequent effects. Compared to methods like open field or elevated platforms for detecting negative emotions, mouse stress is minimal. Both positive and negative emotional experiences can be repeated multiple times within a short period (something previous emotion detection methods could not achieve). This invention enhances the dimensions of mouse emotion detection, providing a comprehensive and objective method. In observing the emotional experience of mice, human psychological experiments often detect emotions across two to three dimensions. However, current animal experiments are often limited to single-dimensional detection. To better adapt animal experiments for clinical research, this invention also detects the emotional experience of mice from two dimensions: a pleasure dimension and an arousal dimension, corresponding to two types of behavioral indicators in mice, to more accurately and objectively quantify the subjective emotional experience of mice. Specifically, the pleasure dimension corresponds to the mouse's ground contact speed and ground contact pressure on the track, while the arousal dimension corresponds to the mouse's speed on the track. By combining the two dimensions in this invention, complex emotions in mice, such as anger, joy, and frustration, can be more accurately assessed. This invention can be used to study abnormal emotional experiences in various mental illness model mice and to regulate brain regions and neural circuits related to abnormal emotional experiences. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the evaluation of the emotional dimension in mice.

[0024] Figure 2 This is a schematic diagram of the training phase.

[0025] Figure 3 This is a diagram for testing unpleasant emotional patterns.

[0026] Figure 4 This is a diagram for testing a pleasant emotional pattern.

[0027] Figure 5 This is a schematic diagram of the behavioral testing process. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The experimental setup for detecting mouse emotions includes a 180*15*10cm box and a gait and posture detection system. The box is made of black acrylic on all sides and top, and transparent glass on the bottom. The box is divided into two parts: the first part consists of a track A (75cm) and a feeding chamber a (15cm), and the second part consists of a track B (75cm) and a feeding chamber b (15cm). The speed and gait information of the mice on the track are detected and analyzed to quantify emotional indicators. Beam-type pressure sensors are installed at the bottom of tracks A and B, and these sensors are based on the HX711 module.

[0030] As an optional embodiment, a camera can be set up to monitor image data, and the image data can be compared and analyzed with the data monitored by the sensor.

[0031] Behavioral testing process

[0032] Restricted diet phase

[0033] During this phase, the experimental mice were housed individually in cages, with restricted food but not water. The mice's weight was recorded daily and maintained at 80% to 90% of their original weight.

[0034] Training phase

[0035] Train the mice to run from track A to chamber a, where they receive a food reward, and then run from track B to chamber b, where they receive another food reward. Repeat this training daily until the mice's running speed gradually stabilizes.

[0036] Emotion detection phase

[0037] After training, the mice ran at a relatively stable speed towards the feeding chambers on the track to receive food rewards. During the testing phase, the unpleasant emotional experience of the mice on track B after not receiving food from chamber a was detected by reducing the probability of obtaining food from chamber a. Conversely, the pleasant emotional experience of the mice on track B was detected by increasing the feeding reward in chamber a.

[0038] Emotional dimension evaluation

[0039] During the training phase, the mice's running speed, ground contact speed, and ground contact pressure were extracted as baseline parameters. During the testing phase, the same parameters were extracted as indicators for measuring emotional experience. Figure 1 The emotional experience of mice was assessed on the pleasure and arousal dimensions. The calculation formula is as follows:

[0040] Pleasure Dimension Index H = (Touch Speed ​​ / Touch Pressure) Test / (Touch Speed ​​ / Touch Pressure) Baseline

[0041] H>1 indicates that the mouse has a pleasant emotional experience, H<1 indicates that the mouse has an unpleasant emotional experience, and H=1 indicates that the mouse has no emotional change. The larger the H value, the more pleasant the emotional experience of the mouse.

[0042] Arousal Dimension Index W = (Runway Walking Speed) Test / (Runway Walking Speed) Baseline

[0043] W>1 indicates that the mouse experiences excitement, W<1 indicates that the mouse experiences calmness, and W=1 indicates that the mouse has no emotional change. The larger the W value, the higher the arousal level of the mouse's emotional experience.

[0044] Interpretation of the emotional dimension: If the H value of the mouse is less than 1 and the W value is greater than 1, it indicates that the mouse is in the anger emotional dimension; if the H value is greater than 1 and the W value is greater than 1, it indicates that the mouse is in the joy emotional dimension; if the H value is less than 1 and the W value is less than 1, the mouse may be in the depression emotional dimension.

[0045] The behavioral testing device includes a box, with the sides and top made of black acrylic material and the bottom made of transparent material. Along its length, the box contains a track A, chamber a, track B, and chamber b. Beam-type pressure sensors are installed at the bottom of tracks A and B to monitor the mouse's walking speed, ground contact speed, and ground contact pressure parameters. (Training phase mode reference) Figure 2 Reference for testing unpleasant emotional patterns Figure 3 Test your positive emotional pattern (reference) Figure 4 ;

[0046] Behavioral testing process reference Figure 5 Specific testing steps:

[0047] (1) The first three days of the experiment were a restricted feeding period. All experimental mice were housed in individual cages and their initial weight was recorded. Water was not restricted. A small amount of mouse food and sugar pills were fed at 8:00 am and 8:00 pm every day to keep the mice's weight at 80%-90% of the baseline level. Their weight was measured every day during the entire behavioral test period to keep them in a state of hunger.

[0048] (2) To help the mice distinguish between the track area and the feeding chamber area, we wiped the track sidewalls with 75% alcohol and the feeding chamber sidewalls with 1% acetic acid during the subsequent training and testing phases. On the first day of the training phase, three sugar pills were placed in chamber a and chamber b respectively. The mice were gently placed at the starting point of track A and allowed to freely explore, run to chamber a, find and eat the sugar pills, and then pass through chamber a to enter track B and run to chamber b to find and eat the sugar pills. In the initial training, if the mouse stayed in any place in the sequence of track A-chamber a-track B for more than 5 minutes without entering the next space, a plastic board was used to gently push the mouse from the opening into the next space. The above steps were followed 10 times a day for 3 consecutive days until the mouse's speed on the track stabilized. If a mouse failed to enter the next space within 5 minutes for 5 consecutive times or a cumulative total of 10 times during training, the mouse was eliminated.

[0049] (3) When testing for pleasant emotional experiences, 8 sugar pills were placed in chamber a and 3 sugar pills were placed in chamber b. When testing for unpleasant emotional experiences, 3 sugar pills were placed in chamber a with a 50% probability and 3 sugar pills were placed in chamber b. After obtaining the speed, ground contact speed, and ground contact pressure parameters of the mice on the track, the pleasantness dimension index H = (ground contact speed / ground contact pressure) test / (ground contact speed / ground contact pressure) baseline and the arousal dimension index W = (track walking speed) test / (track walking speed) baseline were calculated.

[0050] 6. Applications:

[0051] (1) The emotional experiences of mice were detected on two different emotional dimensions: pleasant-unpleasant and arousal level;

[0052] (2) Compare the differences in the degree of emotional experience between normal mice and model mice of mental illnesses (such as anxiety disorders, depression disorders, mania, schizophrenia, etc.), as well as the qualitative differences in arousal dimension and the quantitative differences in arousal degree on the same pleasant emotional dimension, or the differences in arousal dimension on the unpleasant emotional dimension. For example, on the same unpleasant emotional dimension, normal mice may be in a higher arousal dimension and experience anger, while model mice of mental illnesses may be in a lower arousal dimension and experience depression.

[0053] (3) Record or regulate the emotional dimension of mice through optical fiber recording, optogenetics or chemogenetics;

[0054] (4) By detecting the emotional dimension of mice, we can study the characteristics of changes in abnormal emotional experience under relevant mental illness states;

[0055] (5) The improvement of emotional experience by specific treatments was evaluated by detecting the emotional experience of mouse models of relevant mental illnesses.

Claims

1. A two-dimensional objective detection method for quantifying subjective emotions in mice, characterized in that, The enclosure includes a box made of black acrylic material on all sides and top, and a transparent bottom. Along its length, the enclosure is divided into three sections: track A, chamber a, track B, and chamber b. Beam-type pressure sensors are installed at the bottom of tracks A and B to monitor the mouse's walking speed, ground contact speed, and ground contact pressure parameters. The process includes the following steps: Food restriction phase: The experimental mice were housed individually in cages, with food restricted but water not. The weight of the mice was recorded daily and kept at 80% to 90% of their original weight. Training phase: Mice were trained to run from track A to chamber a, where they received a food reward, and then run from track B to chamber b, where they received another food reward. This training was repeated until the mice's running speed gradually stabilized. At the same time, the mice's walking speed, ground contact speed, and ground contact pressure parameters on the track were extracted as baselines. Testing phase: By changing the probability of mice obtaining food in the first chamber, the walking speed, ground contact speed, and ground contact pressure parameters of the mice on the track were monitored, and the emotional experience of the mice on the second track was obtained based on the monitoring results. The emotional experience of mice was assessed on the pleasure and arousal dimensions. The calculation formulas are as follows: Pleasure Dimension Index H = (Touch Speed ​​ / Touch Pressure) Test / (Touch Speed ​​ / Touch Pressure) Baseline H>1 indicates that the mouse has a pleasant emotional experience, H<1 indicates that the mouse has an unpleasant emotional experience, and H=1 indicates that the mouse has no emotional change. The larger the H value, the more pleasant the emotional experience of the mouse. Arousal Dimension Index W = (Runway Walking Speed) Test / (Runway Walking Speed) Baseline W>1 indicates that the mouse experiences excitement, W<1 indicates that the mouse experiences calmness, and W=1 indicates that the mouse has no emotional change. The larger the W value, the higher the arousal level of the mouse's emotional experience. Interpretation of the emotional dimension: If the H value of the mouse is less than 1 and the W value is greater than 1, it indicates that the mouse is in the anger emotional dimension; if the H value is greater than 1 and the W value is greater than 1, it indicates that the mouse is in the joy emotional dimension; if the H value is less than 1 and the W value is less than 1, the mouse may be in the depression emotional dimension.

2. The two-dimensional objective detection method for quantifying subjective emotions in mice according to claim 1, characterized in that, The first three days of the experiment were a restricted feeding period. The mice were fed small amounts of rat food and sugar pills at 8:00 am and 8:00 pm every day to keep their weight at 80%-90% of the baseline level. Their weight was measured every day during the entire behavioral testing period thereafter to keep them in a state of hunger.

3. The two-dimensional objective detection method for quantifying subjective emotions in mice according to claim 1, characterized in that, On the first day of the training phase, three sugar pills were placed in chamber a and chamber b respectively. The mouse was gently placed at the starting point of track A and allowed to explore freely, run to chamber a, find and eat the sugar pill, and then run through chamber a into track B to find and eat the sugar pill. The mouse was trained 10 times a day in this manner for 3 consecutive days until its speed on the track stabilized. When testing for pleasant emotional experiences, 8 sugar pills were placed in chamber a and 3 sugar pills were placed in chamber b. When testing for unpleasant emotional experiences, 3 sugar pills were placed in chamber a with a 50% probability and 3 sugar pills were placed in chamber b. After obtaining the speed, ground contact speed and ground contact pressure parameters of the mice on the track, the pleasantness dimension index H = (ground contact speed / ground contact pressure) test / (ground contact speed / ground contact pressure) baseline and the arousal dimension index W = (track walking speed) test / (track walking speed) baseline were calculated.

4. The two-dimensional objective detection method for quantifying subjective emotions in mice according to claim 3, characterized in that, During both the training and testing phases, the sidewalls of the runway were wiped with 75% alcohol, and the sidewalls of the feeding chamber were wiped with 1% acetic acid.

5. The two-dimensional objective detection method for quantifying subjective emotions in mice according to claim 3, characterized in that, During the initial training, if the mouse stays in any place in the sequence of track A-chamber a-track B for more than 5 minutes without entering the next space, gently push the mouse from the hole into the next space using a plastic board.

6. The two-dimensional objective detection method for quantifying subjective emotions in mice according to claim 3, characterized in that, During the training phase, if a mouse fails to advance to the next step within 5 minutes for a cumulative total of 10 attempts (5 consecutive attempts), it will be eliminated.

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