A method and system for evaluating learning and memory ability of mouse hippocampus based on water maze

Abstract

The present application relates to the technical field of learning and memory evaluation, and provides a mouse hippocampus learning and memory comprehensive evaluation method and system based on Morris water maze, which is different from the traditional method of evaluating learning and memory only by latency, and innovatively introduces a double evaluation mechanism of mouse behavior personality stability and swimming skill, combines training adaptation period, behavior path analysis and weighted score of multi-dimensional behavior indexes, and realizes accurate quantification of hippocampus-dependent spatial learning and memory ability. The experimental indexes include swimming speed, path length, target quadrant residence time and latency, and the evaluation score of memory ability is generated after weighted value assignment and standardization calculation. The present application improves the scientificity, stability and experimental repeatability of the evaluation results, and is suitable for mouse cognitive function evaluation in various research situations such as drug intervention and neurodegenerative disease model.

Description

Technical Field

[0001] This invention belongs to the field of neurobehavioral experimental evaluation technology, specifically relating to a quantitative evaluation method and automated system for mouse hippocampal learning and memory ability combined with the water maze test. Background Technology

[0002] The Morris water maze is a widely used behavioral test method for assessing spatial learning and memory abilities in rodents (such as mice). It evaluates hippocampal-dependent learning and memory abilities by measuring the behavior of mice in searching for hidden platforms within a water maze. Due to its ease of operation and reliable results, the Morris water maze test is widely used in research in neuroscience, pharmacology, psychology, and other fields.

[0003] However, existing Morris water maze tests primarily focus on latency (the time from when a mouse is placed in the water to when it finds the hidden platform) as the main indicator for assessing a mouse's learning and memory abilities. While latency is an important indicator, it does not comprehensively and accurately reflect a mouse's learning and memory capabilities.

[0004] In addition, there are differences in personality and swimming skills among mice, such as anxiety level and exploratory behavior. These personality traits can affect the behavior of mice in the water maze, and mice with poor swimming skills may show a longer latency in the water maze. Traditional methods do not assess the personality and swimming skills of mice, which leads to the interference of individual differences in experimental results, thereby reducing the accuracy of experimental results. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for evaluating the learning and memory abilities of the mouse hippocampus based on the water maze, thereby solving the problems of insufficient comprehensiveness and low accuracy of experimental indicators in the existing technology.

[0006] To achieve the above objectives, this invention provides a method for evaluating the learning and memory abilities of the mouse hippocampus based on the water maze, comprising the following steps:

[0007] S1. Conduct personality and swimming skill assessments on healthy adult mice. Select mice that meet the preset assessment criteria as experimental subjects. One day before the experiment, allow the mice to swim freely for 2 minutes in the Morris water maze without platforms and markers to adapt to the aquatic environment.

[0008] S2. Divide the Morris water maze into different quadrants and conduct a training test on the mice before the experiment to help them develop an impression of the platform in the water.

[0009] S3. Place the mice in different quadrants of the Morris water maze and obtain and record the comprehensive experimental indicators.

[0010] The comprehensive experimental indicators include mouse swimming speed, swimming path length, time spent in the target quadrant, and latency.

[0011] S4. Repeat step S3 with each mouse at 4-hour intervals to obtain multiple sets of comprehensive experimental indicators for each mouse. Then, comprehensively evaluate the multiple sets of comprehensive experimental indicators of multiple mice to obtain the evaluation results of the learning and memory ability of the mouse hippocampus.

[0012] In some embodiments of this application, in S1, personality and swimming skills are assessed in healthy adult mice, and mice that meet the preset assessment criteria are selected as experimental evaluation subjects, including:

[0013] Healthy adult mice were assessed for personality stability and swimming skill competence, and the personality stability assessment value and swimming skill competence assessment value of each mouse were obtained.

[0014] The personality stability assessment value and swimming skill qualification assessment value of each mouse were comprehensively analyzed to obtain the comprehensive assessment result. Mice whose comprehensive assessment results met the preset assessment criteria were used as experimental evaluation subjects.

[0015] In some embodiments of this application, in S1, the personality stability of healthy adult mice is assessed, and the personality stability assessment value for each mouse includes:

[0016] The personality stability test of mice was conducted using the elevated cross maze method. Mice were placed in the central area of ​​the elevated cross maze, and behavioral indicators of the mice were measured and recorded within 5 minutes, including the number of times the mice entered the open and closed arms and the time spent in the open and closed arms.

[0017] Mice were subjected to a second and third test 24 and 48 hours after the first test, respectively. The mice were placed in the central area of ​​the elevated cross maze again, and the same behavioral indicators were recorded.

[0018] The variation index of the number of times the mouse entered the open arm and the time spent in the open arm was calculated in three tests, and the personality stability of the mouse was evaluated based on the variation index.

[0019] In some embodiments of this application, in S1, a swimming skill qualification assessment is performed on healthy adult mice, and the swimming skill qualification assessment value for each mouse includes:

[0020] Mice were placed in a platformless pool, and their swimming skills were measured and recorded within 3 minutes. The swimming skills indicators included swimming speed and body tilt.

[0021] Swimming skill qualification assessment values ​​were obtained based on mouse swimming skill indicators.

[0022] In some embodiments of this application, in S2, the training test performed on the experimental mice to establish an impression of the platform in the water includes:

[0023] Mice were placed in water from different quadrants of a water maze and allowed to find the platforms on their own. If a mouse failed to find a platform within 1 minute, it was manually guided to the platform and allowed to stay on it for 15-30 seconds to reinforce its memory of the platform's location.

[0024] In some embodiments of this application, in S3, mice are placed in different quadrants of the Morris water maze, and comprehensive experimental indicators are obtained and recorded, including:

[0025] Mice were placed in a randomly selected quadrant of a water maze, and a video tracking system was activated to record the mice’s movements, obtaining their swimming speed, swimming path length, time spent in the target quadrant, and latency indicators.

[0026] Among them, the latency period is the time from when the mouse is put into the water until it finds and climbs onto the platform in the water; the swimming speed is the average swimming speed of the mouse in the water maze; the swimming path length is the length of the swimming trajectory of the mouse from the starting position to when it finds the platform in the water; and the target quadrant dwell time is the time the mouse spends in the quadrant where the platform is located before finding the platform in the water.

[0027] In some embodiments of this application, in S4, a comprehensive evaluation of multiple sets of experimental indicators of multiple mice is performed to obtain the evaluation results of the learning and memory ability of the mouse hippocampus, including:

[0028] Based on the importance of each experimental indicator, an importance weight is assigned to each indicator. Each experimental indicator in a set of comprehensive experimental indicators is standardized and weighted to obtain an evaluation score for a set of comprehensive experimental indicators.

[0029] The evaluation scores of multiple sets of comprehensive experimental indicators were compared and analyzed, and the learning and memory abilities of the mouse hippocampus were evaluated based on the comparison and analysis results.

[0030] In some embodiments of this application, a water maze-based mouse hippocampal learning and memory ability evaluation system is also disclosed, comprising:

[0031] The selection module was used to assess the personality and swimming skills of healthy adult mice. Mice that met the preset assessment criteria were selected as experimental subjects. The mice were allowed to swim freely for 2 minutes in the Morris water maze without platforms and markers the day before the experiment, so that the mice could adapt to the aquatic environment.

[0032] The training module is used to divide the Morris water maze into different quadrants and conduct a training period test on the experimental mice before the experiment begins, so that the experimental mice can form an impression of the platform in the water.

[0033] The experimental module is used to place mice in different quadrants of the Morris water maze and obtain and record comprehensive experimental indicators, including the mouse's swimming speed, swimming path length, time spent in the target quadrant, and latency.

[0034] The evaluation module is used to repeat step S3 for each mouse at 4-hour intervals to obtain multiple sets of comprehensive experimental indicators for each mouse, and to comprehensively evaluate the multiple sets of comprehensive experimental indicators of multiple mice to obtain the evaluation results of the learning and memory ability of the mouse hippocampus.

[0035] The advantages and beneficial effects of this invention compared to the prior art are:

[0036] 1. This invention screens mice that meet pre-defined criteria for experimental subjects by assessing their personality and swimming skills before the experiment. This ensures consistency in personality and swimming ability among the experimental mice, reduces the impact of individual differences on experimental results, and thus improves the accuracy and reliability of the experiment.

[0037] 2. This invention conducts a training period test before the experiment begins to help mice establish an impression of the platform in the water, enabling them to better complete the experimental tasks and improve the success rate and validity of the data.

[0038] 3. The comprehensive experimental indicators proposed in this invention include the mouse's swimming speed, swimming path length, target quadrant dwell time, and latency, which reflect the mouse's learning and memory abilities from multiple perspectives. This allows for a more comprehensive assessment of the mouse's hippocampal learning and memory abilities. By assigning importance weights to each experimental indicator based on its importance and standardizing each indicator, the learning and memory abilities of the mouse can be assessed more objectively, greatly improving the comprehensiveness of the evaluation indicators.

[0039] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0040] Figure 1 This is a schematic diagram illustrating the steps of a method for evaluating the learning and memory abilities of the mouse hippocampus based on a water maze, as described in an embodiment of the present invention.

[0041] Figure 2 This is a schematic diagram of a mouse hippocampal learning and memory ability evaluation system based on a water maze, as described in an embodiment of the present invention. Detailed Implementation

[0042] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0044] like Figure 1 As shown, this invention provides a method for evaluating the learning and memory abilities of the mouse hippocampus based on the water maze, comprising the following steps:

[0045] S1 Mouse Selection: Mice were tested three times at intervals using an elevated cross maze to obtain the coefficient of variation for personality stability; their swimming ability was tested for 3 minutes in a platform-less water maze, and their speed and postural stability were recorded; only mice with stable personalities and satisfactory swimming skills were selected as experimental subjects. S2 Adaptation Training Phase: One day before the experiment, mice swam freely in a platform-less water maze for 2 minutes to adapt to the aquatic environment; three days of training were conducted before the formal experiment, during which mice repeatedly entered the water maze to search for platforms, and those that could not find a platform were guided to the platform to reinforce spatial awareness.

[0046] S3 Experimental Evaluation Phase: Mice entered the water from a random quadrant, and their platform-finding behavior was recorded via video. Four data points were collected: a. latency; b. swimming speed; c. path length; d. time spent in the target quadrant.

[0047] S4 Multiple Tests and Comprehensive Scoring: The experiment is repeated every 4 hours for at least 3 times; the collected indicators are standardized and the comprehensive memory score for each experiment is calculated according to the preset weights; the multiple scores are summarized and analyzed to generate the final hippocampal learning and memory ability evaluation value.

[0048] The Morris Water Maze (MWM) is a classic experimental paradigm used to assess the spatial learning and memory abilities of rodents. It typically consists of a pool, hidden platforms in the water, visual markers, and a video tracking system. The Morris Water Maze experiment is based on the escape motivation of mice. Mice dislike swimming, so in a water maze, they will try to find hidden platforms to escape the aquatic environment. Through repeated training, mice can remember the locations of the platforms, thus assessing their spatial learning and memory abilities.

[0049] In some embodiments of this application, in S1, personality and swimming skills are assessed in healthy adult mice, and mice that meet the preset assessment criteria are selected as experimental evaluation subjects, including:

[0050] Healthy adult mice were assessed for personality stability and swimming skill competence, and the personality stability assessment value and swimming skill competence assessment value of each mouse were obtained.

[0051] The personality stability assessment value and swimming skill qualification assessment value of each mouse were comprehensively analyzed to obtain the comprehensive assessment result. Mice whose comprehensive assessment results met the preset assessment criteria were used as experimental evaluation subjects.

[0052] In some embodiments of this application, in S1, the personality stability of healthy adult mice is assessed, and the personality stability assessment value for each mouse includes:

[0053] The personality stability test of mice was conducted using the elevated cross maze method. Mice were placed in the central area of ​​the elevated cross maze, and behavioral indicators of the mice were measured and recorded within 5 minutes, including the number of times the mice entered the open and closed arms and the time spent in the open and closed arms.

[0054] Mice were subjected to a second and third test 24 and 48 hours after the first test, respectively. The mice were placed in the central area of ​​the elevated cross maze again, and the same behavioral indicators were recorded.

[0055] The variation index of the number of times the mouse entered the open arm and the time spent in the open arm was calculated in three tests, and the personality stability of the mouse was evaluated based on the variation index.

[0056] Significant personality differences exist among mice, influencing their behavior in water mazes. For example, some mice may be timid and anxious, while others may be bolder and more active. These personality traits affect a mouse's adaptability to new environments, exploratory behavior, and memory of hidden platforms. The stability of a mouse's personality was assessed by repeatedly testing its behavior in an elevated cruciform maze. For example, the number of times a mouse entered open and closed arms, and the time spent in each arm were recorded. The stability of a mouse's personality was determined by comparing the coefficients of variation of the results from multiple tests.

[0057] In some embodiments of this application, in S1, a swimming skill qualification assessment is performed on healthy adult mice, and the swimming skill qualification assessment value for each mouse includes:

[0058] Mice were placed in a platformless pool, and their swimming skills were measured and recorded within 3 minutes. The swimming skills indicators included swimming speed and body tilt.

[0059] Swimming skill competence assessment values ​​were obtained based on mouse swimming skill indicators. Some mice may be naturally strong swimmers, while others may be weak. This difference can affect their performance in water mazes, especially when searching for hidden platforms. Therefore, this application uses swimming skill assessment to select mice with normal swimming ability as experimental subjects. These mice exhibit more consistent behavior during the experiment, thereby reducing errors caused by differences in swimming skill and improving the accuracy and reliability of the experiment.

[0060] In some embodiments of this application, in S2, the training test performed on the experimental mice to establish an impression of the platform in the water includes:

[0061] Mice were placed in water from different quadrants of a water maze and allowed to find the platforms on their own. If a mouse failed to find a platform within 1 minute, it was manually guided to the platform and allowed to stay on it for 15-30 seconds to reinforce its memory of the platform's location.

[0062] It is important to understand that mice may exhibit a high level of stress response, such as struggling and trying to escape, when they first enter a water maze. Through training tests, mice can gradually adapt to the water maze environment, reducing the interference of stress response on experimental results.

[0063] In some embodiments of this application, in S3, mice are placed in different quadrants of the Morris water maze, and comprehensive experimental indicators are obtained and recorded, including:

[0064] Mice were placed in a randomly selected quadrant of a water maze, and a video tracking system was activated to record the mice’s movements, obtaining their swimming speed, swimming path length, time spent in the target quadrant, and latency indicators.

[0065] Among them, the latency period is the time from when the mouse is put into the water until it finds and climbs onto the platform in the water; the swimming speed is the average swimming speed of the mouse in the water maze; the swimming path length is the length of the swimming trajectory of the mouse from the starting position to when it finds the platform in the water; and the target quadrant dwell time is the time the mouse spends in the quadrant where the platform is located before finding the platform in the water.

[0066] In some embodiments of this application, in S4, a comprehensive evaluation of multiple sets of experimental indicators of multiple mice is performed to obtain the evaluation results of the learning and memory ability of the mouse hippocampus, including:

[0067] Based on the importance of each experimental indicator, an importance weight is assigned to each indicator. Each experimental indicator in a set of comprehensive experimental indicators is standardized and weighted to obtain an evaluation score for a set of comprehensive experimental indicators.

[0068] The evaluation scores of multiple sets of comprehensive experimental indicators were compared and analyzed, and the learning and memory abilities of the mouse hippocampus were evaluated based on the comparison and analysis results.

[0069] Specifically, the core of this scheme lies in using scientific methods to weight and standardize multiple experimental indicators, thereby more comprehensively and accurately assessing the learning and memory abilities of mice. By assigning importance weights to each indicator, standardizing each indicator, and performing weighted calculations, an evaluation score for each set of comprehensive experimental indicators is obtained. Then, the evaluation scores of multiple sets of comprehensive experimental indicators are compared and analyzed. Based on the comparison and analysis results, the learning and memory abilities of the mouse hippocampus are evaluated. According to the importance of each experimental indicator in assessing the learning and memory abilities of mice, a weight is assigned to each indicator. The sum of the weights should be 1. Since the dimensions and numerical ranges of each indicator are different, each indicator needs to be standardized so that its value is between 0 and 1. The standardized values ​​of each indicator are then weighted and calculated to obtain an evaluation score for a set of comprehensive experimental indicators. Step S3 is repeated for each mouse at 4-hour intervals to obtain multiple sets of evaluation scores for comprehensive experimental indicators.

[0070] In one embodiment, mouse A's overall evaluation score was 0.4, which was below the threshold of 0.6 but close to the threshold, and its learning and memory abilities could be considered to be close to normal. Mouse B's overall evaluation score was 0.2, which was far below the threshold of 0.4, and its learning and memory abilities could be considered to be abnormal.

[0071] like Figure 2 As shown, in some embodiments of this application, a water maze-based mouse hippocampal learning and memory ability evaluation system is also disclosed, including:

[0072] The selection module is used to assess the personality and swimming skills of healthy adult mice. Mice that meet the preset assessment criteria are selected as experimental subjects. The mice to be tested are allowed to swim freely for 2 minutes in the Morris water maze without platforms and markers the day before the experiment, so that the mice can adapt to the aquatic environment.

[0073] The training module is used to divide the Morris water maze into different quadrants and conduct a training period test on the experimental mice before the experiment begins, so that the experimental mice can form an impression of the platform in the water.

[0074] The experimental module is used to place mice in different quadrants of the Morris water maze to obtain and record comprehensive experimental indicators, including the mouse's swimming speed, swimming path length, time spent in the target quadrant, and latency.

[0075] The evaluation module is used to repeat step S3 for each mouse at 4-hour intervals to obtain multiple sets of comprehensive experimental indicators for each mouse, and to comprehensively evaluate the multiple sets of comprehensive experimental indicators of multiple mice to obtain the evaluation results of the learning and memory ability of the mouse hippocampus.

[0076] The overall advantages of this invention are:

[0077]

Claims

1. A method for evaluating learning and memory abilities in the mouse hippocampus based on a water maze, characterized in that, Includes the following steps: S1. Conduct personality and swimming skill assessments on healthy adult mice. Select mice that meet the preset assessment criteria as experimental subjects. One day before the experiment, allow the mice to swim freely for 2 minutes in the Morris water maze without platforms and markers to adapt to the aquatic environment. In step S1, personality and swimming skills are assessed in healthy adult mice. Mice that meet the preset assessment criteria are selected as experimental evaluation subjects, including: Healthy adult mice were assessed for personality stability and swimming skill competence, and the personality stability assessment value and swimming skill competence assessment value of each mouse were obtained. The personality stability assessment value and swimming skill qualification assessment value of each mouse were comprehensively analyzed to obtain the comprehensive assessment result, and mice whose comprehensive assessment results met the preset assessment criteria were used as experimental evaluation subjects. In step S1, the personality stability of healthy adult mice is assessed, and the personality stability assessment value for each mouse includes: The personality stability test of mice was conducted using the elevated cross maze method. Mice were placed in the central area of ​​the elevated cross maze, and behavioral indicators of the mice were measured and recorded within 5 minutes, including the number of times the mice entered the open and closed arms and the time spent in the open and closed arms. Mice were subjected to a second and third test 24 and 48 hours after the first test, respectively. The mice were placed in the central area of ​​the elevated cross maze again, and the same behavioral indicators were recorded. The variation index of the number of times the mouse entered the open arm and the time spent in the open arm was calculated in three tests, and the personality stability assessment value of the mouse was obtained based on the variation index. S2. Divide the Morris water maze into different quadrants and conduct a training test on the mice before the experiment to help them develop an impression of the platform in the water. S3. Place the mice in different quadrants of the Morris water maze and obtain and record the comprehensive experimental indicators. The comprehensive experimental indicators include mouse swimming speed, swimming path length, time spent in the target quadrant, and latency. S4. Repeat step S3 with each mouse at 4-hour intervals to obtain multiple sets of comprehensive experimental indicators for each mouse. Then, comprehensively evaluate the multiple sets of comprehensive experimental indicators of multiple mice to obtain the evaluation results of the learning and memory ability of the mouse hippocampus.

2. The method for evaluating mouse hippocampal learning and memory ability based on the water maze according to claim 1, characterized in that, In step S1, the swimming skill qualification of healthy adult mice is assessed, and the swimming skill qualification value of each mouse includes: Mice were placed in a platformless pool, and their swimming skills were measured and recorded within 3 minutes. The swimming skills indicators included swimming speed and body tilt. Swimming skill qualification assessment values ​​were obtained based on mouse swimming skill indicators.

3. The method for evaluating learning and memory abilities in the mouse hippocampus based on the water maze, as described in claim 2, is characterized in that... In S2, the training period test for the experimental mice, which enables the mice to establish an impression of the platform in the water, includes: Mice were placed in water from different quadrants of a water maze and allowed to find the platforms on their own. If a mouse failed to find a platform within 1 minute, it was manually guided to the platform and allowed to stay on it for 15-30 seconds to reinforce its memory of the platform's location.

4. The method for evaluating learning and memory abilities in the mouse hippocampus based on the water maze, as described in claim 3, is characterized in that... In step S3, mice are placed in different quadrants of the Morris water maze, and comprehensive experimental indicators are obtained and recorded, including: Mice were placed in a randomly selected quadrant of a water maze, and a video tracking system was activated to record the mice’s movements, obtaining their swimming speed, swimming path length, time spent in the target quadrant, and latency indicators. Among them, the latency period is the time from when the mouse is put into the water until it finds and climbs onto the platform in the water; the swimming speed is the average swimming speed of the mouse in the water maze; the swimming path length is the length of the swimming trajectory of the mouse from the starting position to when it finds the platform in the water; and the target quadrant dwell time is the time the mouse spends in the quadrant where the platform is located before finding the platform in the water.

5. The method for evaluating learning and memory abilities in the mouse hippocampus based on the water maze, as described in claim 4, is characterized in that... In S4, a comprehensive evaluation of multiple sets of experimental indicators from multiple mice was conducted to obtain the evaluation results of the mouse hippocampal learning and memory abilities, including: Based on the importance of each experimental indicator, an importance weight is assigned to each indicator. Each experimental indicator in a set of comprehensive experimental indicators is standardized and weighted to obtain an evaluation score for a set of comprehensive experimental indicators. The evaluation scores of multiple sets of comprehensive experimental indicators were compared and analyzed, and the learning and memory abilities of the mouse hippocampus were evaluated based on the comparison and analysis results.

6. A water maze-based mouse hippocampal learning and memory assessment system, used to implement the water maze-based mouse hippocampal learning and memory assessment method as described in any one of claims 1-5, characterized in that, include: The selection module was used to assess the personality and swimming skills of healthy adult mice. Mice that met the preset assessment criteria were selected as experimental subjects. The mice were allowed to swim freely for 2 minutes in the Morris water maze without platforms and markers the day before the experiment, so that the mice could adapt to the aquatic environment. The training module is used to divide the Morris water maze into different quadrants and conduct a training period test on the experimental mice before the experiment begins, so that the experimental mice can form an impression of the platform in the water. The experimental module is used to place mice in different quadrants of the Morris water maze and obtain and record comprehensive experimental indicators, including the mouse's swimming speed, swimming path length, time spent in the target quadrant, and latency. The evaluation module is used to repeat step S3 for each mouse at 4-hour intervals to obtain multiple sets of comprehensive experimental indicators for each mouse, and to comprehensively evaluate the multiple sets of comprehensive experimental indicators of multiple mice to obtain the evaluation results of the learning and memory ability of the mouse hippocampus.

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