Devices and methods for free exploration of different spatial dimensions based on rich information

Abstract

This invention discloses a device and method for free exploration in different spatial dimensions based on rich information, including: a one-dimensional ring-shaped unidirectional free exploration device, a two-dimensional open field free exploration device, and a three-dimensional behavior box free exploration device. Using the free exploration devices in different spatial dimensions can not only explore the spatial information representation of rat hippocampal position cells in different spatial dimensions, but also explore whether there is a certain time-varying law in the dynamic changes of rat spatial information encoding ability under long-term simulated microgravity. This creates conditions for further exploring the internal neural mechanisms of the influence of simulated microgravity factors on spatial memory and other aspects.

Description

Technical Field

[0001] This invention belongs to the field of task technology for rats to freely explore in different spatial dimensions, specifically relating to a device and method for a paradigm of free exploration in different spatial dimensions based on rich information. Background Technology

[0002] There exists a type of neuron in the hippocampus that can specifically represent spatial information, called place cells. These cells can fire action potentials at specific locations, which are called the place domains of the place cells. This is considered to be the basis for the brain's spatial cognitive map. Whether the cognitive map is three-dimensional, how it is represented in different spatial dimensions, and how it integrates spatial information from different dimensions are all areas of great interest for exploration.

[0003] With the rapid innovation and development of manned spaceflight technology, my country has entered a new stage of space station application development. When astronauts enter space, they are in a high-vacuum, high-radiation, and frequently alternating day and night environment. Space stations, where astronauts work and live for extended periods, also present challenges such as cramped spaces, high noise levels, prolonged social isolation, and microgravity. In space, gravity is only one millionth of Earth's gravity, making the vastly different microgravity environment one of the most important initiating factors affecting life in space. Under the long-term influence of this special environment, astronauts' vestibular and cognitive functions undergo adaptive changes. Based on microgravity testing of rodents, studies on their learning and memory cognitive functions revealed that in the water maze test, the latency time increased after 28 days of microgravity modeling. In the Y-maze test, the reaction accuracy significantly decreased and the reaction time significantly increased after 3 days of simulated weightlessness modeling. This indicates a decline in the spatial learning and memory functions of rodents.

[0004] Current research indicates that due to the microgravity environment in space, rodents mostly exhibit floating and hovering movements, and are more likely to explore three-dimensional space. However, the neural mechanisms by which rats encode spatial information in three-dimensional space on Earth are different from those in two-dimensional planes. It is still unclear how simulated microgravity affects rats' encoding of spatial information in different spatial dimensions. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a device for a free exploration paradigm based on rich information in different spatial dimensions.

[0006] Another objective of this invention is to provide a method based on a free exploration paradigm in different spatial dimensions with rich information. This method investigates the spatial information encoding ability of rats under simulated microgravity when they freely explore in different spatial dimensions with rich information, as well as the internal neural mechanisms, based on a free exploration paradigm device in different spatial dimensions.

[0007] The objective of this invention is achieved through the following technical solution.

[0008] A device for free exploration in different spatial dimensions based on rich information includes: a one-dimensional ring-shaped unidirectional free exploration device, a two-dimensional open field free exploration device, and a three-dimensional behavior box free exploration device, wherein...

[0009] The one-dimensional ring-shaped unidirectional free exploration paradigm device includes: a ring-shaped track and a first rich information, the first rich information being fixed on the base plate of the ring-shaped track;

[0010] The two-dimensional open field free exploration paradigm device includes: a cube-shaped cavity with an open top surface, and second rich information is randomly and sequentially fixed on the bottom surface of the cube-shaped cavity;

[0011] The three-dimensional behavior box free exploration paradigm device includes: a behavior box, a third enrichment information, and a hanging rod. The behavior box is a rectangular box with an opening on the top surface. The hanging rod is installed inside the behavior box. The third enrichment information is fixed to the bottom surface and the inner side wall of the behavior box. The hanging rod is fixed to the lower part of the center of the top surface of the behavior box and is used to suspend rodents.

[0012] In the above technical solution, the opening is located at the center of the top surface of the cuboid box.

[0013] In the above technical solution, the ring track includes: an outer three-dimensional regular M-sided ring structure and an inner three-dimensional regular M-sided ring structure. The outer three-dimensional regular M-sided ring structure is a regular M-sided column formed by M first side plates, and the inner three-dimensional regular M-sided ring structure is a regular M-sided column formed by M second side plates. The bottom edge length of the first side plate is greater than the bottom edge length of the second side plate. The outer three-dimensional regular M-sided ring structure is nested outside the inner three-dimensional regular M-sided ring structure and the two are concentrically arranged. The bottom edge of the outer three-dimensional regular M-sided ring structure and the bottom edge of the inner three-dimensional regular M-sided ring structure are connected by the base plate, so that the outer three-dimensional regular M-sided ring structure and the inner three-dimensional regular M-sided ring structure form the ring track.

[0014] In the above technical solution, both the first side plate and the second side plate are rectangular.

[0015] In the above technical solution, the first rich information is randomly fixed on the base plate.

[0016] In the above technical solution, the first enriched information, the second enriched information, and the third enriched information respectively include: objects of different colors and shapes, used to enrich visual and tactile information.

[0017] A method based on a free exploration paradigm in different spatial dimensions using rich information includes the following steps: A formal experiment is conducted on rodents for N days using a free exploration paradigm device in different spatial dimensions. During the formal experiment, the rodents are subject to food restriction each day. Each day's experiment includes S1-1, S1-2, and S1-3 in sequence, with the rodents resting for at least 3 minutes between S1-1, S1-2, and S1-3.

[0018] S1-1, Place the rodent on the circular track of the one-dimensional ring-shaped free exploration paradigm device for two unidirectional free explorations. After each unidirectional free exploration, allow the rodent to leave the circular track and rest for at least 3 minutes. During the unidirectional free exploration, ensure that the rodent is given food as a reward at least once during each unidirectional free exploration. If the rodent stops exploring, give food at a random location on the circular track as a reward to encourage the rodent to continue exploring until the circular track is fully explored.

[0019] S1-2, place rodents in a two-dimensional open field free exploration paradigm device and allow them to begin a 10-minute free exploration period. After the free exploration ends, allow the rodents to leave the two-dimensional open field free exploration paradigm device. During the free exploration, the rodents explore freely for the first 5 minutes, and food is placed at random locations in the two-dimensional open field free exploration paradigm device as a reward for the last 5 minutes, encouraging the rodents to explore the entire area of ​​the two-dimensional open field free exploration paradigm device.

[0020] S1-3: Place the rodent in a three-dimensional behavior box free exploration paradigm device and allow the rodent to begin a 10-minute free exploration.

[0021] This invention presents a free exploration paradigm device in different spatial dimensions, encompassing spatial information from one-dimensional to two-dimensional and then to three-dimensional space. It enables rapid and flexible conversion between dimensions, facilitating continuous experimentation within a short period. Furthermore, the three-dimensional behavioral box free exploration paradigm device in this invention more closely resembles the spatial exploration pattern of rats in space, providing an important scientific foundation for subsequent investigations into the representation patterns of rat information in different spatial dimensions under simulated microgravity. This invention provides a feasible method for current research on rats' representation of spatial information in different spatial dimensions and for exploring the impact of simulated microgravity on rats' spatial cognitive abilities in different spatial dimensions.

[0022] Using a free exploration paradigm device with different spatial dimensions can not only investigate the spatial information representation of rat hippocampal position cells in different spatial dimensions, but also explore whether there is a certain time-varying pattern in the dynamic changes of rat spatial information encoding ability under long-term simulated microgravity. This creates conditions for further exploring the internal neural mechanisms of the effects of simulated microgravity factors on spatial memory and other aspects. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the one-dimensional ring-shaped unidirectional free exploration paradigm device of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the two-dimensional open field free exploration paradigm device of the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of the three-dimensional behavior box free exploration paradigm device of the present invention;

[0026] Figure 4 This is a flowchart of the method of the present invention;

[0027] Figure 5 The (A) trajectory and (B) angular velocity of rats in a one-dimensional annular unidirectional free exploration paradigm device simulating microgravity (SM) and control (CON) groups;

[0028] Figure 6 The (A) trajectory and (B) velocity of rats in a simulated microgravity group (SM) and a control group (CON) in a two-dimensional open field free exploration paradigm device;

[0029] Figure 7 The image shows the cell discharge rate heatmaps (A), peak discharge rate, and average discharge rate of cells in the hippocampus of rats in a simulated microgravity group (microgravity) and control group (control) in a two-dimensional open field free exploration paradigm device.

[0030] Figure 8 The image shows the cell discharge rate heatmaps (A), peak discharge rate, and average discharge rate of hippocampal cells in rats in the simulated microgravity group (microgravity) and control group (control) in a three-dimensional behavior box free exploration paradigm device.

[0031] Among them, 1: base plate, 2: outer three-dimensional regular dodecagonal ring structure (M=12), 3: inner three-dimensional regular dodecagonal ring structure (M=12), 4: first rich information, 5: cube-shaped cavity, 6: second rich information, 7: behavior box, 8: third rich information, 9: opening, 10: hanging rod. Detailed Implementation

[0032] The following detailed description of the device and method for free exploration of different spatial dimensions based on rich information, in conjunction with the accompanying drawings, will be provided below.

[0033] Example 1

[0034] like Figure 1 As shown, a free exploration paradigm device based on rich information in different spatial dimensions includes: a one-dimensional ring-shaped unidirectional free exploration paradigm device, a two-dimensional open field free exploration paradigm device, and a three-dimensional behavior box free exploration paradigm device, wherein...

[0035] The one-dimensional ring-shaped unidirectional free exploration paradigm device includes: an outer solid regular dodecagonal ring structure 2, an inner solid regular dodecagonal ring structure 3, and first rich information 4. The outer solid regular dodecagonal ring structure is a regular dodecagonal prism (open at the top) surrounded by twelve first side plates, and the inner solid regular dodecagonal ring structure is a regular dodecagonal prism (open at the top) surrounded by twelve second side plates. The bottom edge length of the first side plate is greater than the bottom edge length of the second side plate. The outer solid regular dodecagonal ring structure is nested outside the inner solid regular dodecagonal ring structure and the two are concentrically arranged. A base plate 1 (in this embodiment, the base plate is made of flooring) is connected between the bottom edge of the outer solid regular dodecagonal ring structure and the bottom edge of the inner solid regular dodecagonal ring structure so that the outer solid regular dodecagonal ring structure and the inner solid regular dodecagonal ring structure form a ring track.

[0036] Both the first and second side panels are rectangular. The bottom side of the first side panel is 33cm long and the height of the first side panel is 40cm. The bottom side of the second side panel is 28cm long and the height of the second side panel is 20cm.

[0037] The first rich information is randomly fixed on the base plate every day, and the first rich information of the one-dimensional ring-shaped unidirectional free exploration paradigm device remains unchanged every day.

[0038] Two-dimensional open-field free exploration paradigm device, such as Figure 2 As shown, it includes: a cube-shaped cavity 5 with an open top surface, and second rich information 6 randomly and sequentially fixed on the bottom surface of the two-dimensional open field free exploration paradigm device. The bottom side length of the cube-shaped cavity is 56cm, and the height of the cube-shaped cavity is 20cm; the fixed order of the second rich information is randomly changed once a day before the start of the experiment.

[0039] A three-dimensional behavioral box free exploration paradigm device, such as Figure 3As shown, the device includes: a transparent behavior box 7 (made of acrylic material), a third rich information 8, and a hanging rod 10 (in this embodiment, the hanging rod is a stainless steel rod-shaped structure with a diameter of 2mm and a length of 40cm). The behavior box is a rectangular box with an opening 9 on the top surface. The bottom surface of the rectangular box is 40cm × 40cm, and the height of the rectangular box is 45cm. The opening is a square of 15cm × 15cm, located at the center of the top surface of the rectangular box. The hanging rod is installed inside the behavior box. The third rich information is located inside the behavior box and is randomly fixed to the bottom surface and the inner side wall of the behavior box. The hanging rod is fixed to the lower part of the center of the top surface of the behavior box. When the rat is in the three-dimensional behavior box free exploration paradigm device, the hanging rod is used to suspend the rat for simulating microgravity modeling.

[0040] The first, second, and third enrichment information include objects of different colors and shapes. In order to enrich the visual and tactile information of the rat, in this embodiment, the first, second, and third enrichment information are respectively three-dimensional small building blocks of different colors and shapes, stickers of different shapes made of different colored washi tape, and three-dimensional rubber toys of fruits or vegetables.

[0041] Example 2

[0042] like Figure 4 As shown, a method for a free exploration paradigm based on rich information in different spatial dimensions includes the following steps:

[0043] Rats were subjected to a 24-hour food restriction program, with the restriction standard being that each rat was only allowed to eat 5% of its body weight in rat food per day.

[0044] The free exploration paradigm device with different spatial dimensions described in Example 1 was used to conduct a formal experiment on rats for 28 days. During the formal experiment, the rats were fed a restricted diet each day. The daily experiment included S1-1, S1-2, and S1-3 in sequence, with the rats resting for 5 minutes between each S1-1, S1-2, and S1-3 exercise.

[0045] S1-1: Place rats on the circular track of a one-dimensional ring-shaped unidirectional free exploration paradigm device for two unidirectional free explorations, each lasting 10 minutes. After each unidirectional free exploration, the rats are removed from the circular track and rest for 5 minutes. During the unidirectional free exploration, the rats are rewarded with food at least once per unidirectional free exploration (the placement location is random). If the rats stop exploring, food is placed at random locations on the circular track as a reward to encourage them to continue exploring until the circular track is completed. If a rat turns to explore an area it has already explored, it is immediately blocked back with cardboard to encourage it to continue exploring unexplored areas.

[0046] S1-2, rats were placed in a two-dimensional open field free exploration paradigm device and allowed to begin a 10-minute free exploration period. After the free exploration ended, the rats were removed from the two-dimensional open field free exploration paradigm device and rested for 5 minutes. During the free exploration, the rats explored freely for the first 5 minutes, and food was placed at random locations in the two-dimensional open field free exploration paradigm device as a reward for the last 5 minutes, encouraging the rats to explore the entire area of ​​the two-dimensional open field free exploration paradigm device.

[0047] S1-3, the rats were placed in a three-dimensional behavioral box free exploration paradigm device, allowing the rats to begin a 10-minute free exploration period.

[0048] All procedures involving the placement of rats should be performed in a manner that avoids causing stress to the rats. Before the start of each day's experiment, the rats should be placed in the experimental room to familiarize themselves with the environment for 20 minutes.

[0049] Popcorn crumbs are used as a reward food.

[0050] Example 3

[0051] To verify the feasibility of the method of the present invention, the following experiments were conducted:

[0052] Simulated microgravity group: Rats were suspended for 28 days using the animal suspension device in CN117297820A, and the method in Example 2 was performed once a day. After the procedure was completed, the animal suspension device in CN117297820A was used to suspend the rats again. In the simulated microgravity modeling group, when the rats were in the three-dimensional behavior box free exploration paradigm device, they were suspended from the hanging rod in the three-dimensional behavior box free exploration paradigm device.

[0053] Control group: Another rat was normally fed for 28 days and the method in Example 2 was performed once a day. In the control group, when the rat was in the three-dimensional behavior box free exploration paradigm device, it was allowed to explore freely (without hanging the rat on the bar).

[0054] The trajectories of rats in the simulated microgravity modeling group and the control group running in a one-dimensional circular unidirectional free exploration paradigm device were converted into radians and plotted. The trajectories on day 2 and day 18 are shown below. Figure 5 As shown in Figure A, by comparing the trajectories of the simulated microgravity group and the control group, the distances of their trajectories are different. Further statistical analysis was conducted on the simulated microgravity group over a continuous 28 days. Figure 5 SM) and control group ( Figure 5 The angular velocity of the movement of the CON rat, such as Figure 5 As shown in Figure B, the motion speed of the simulated microgravity group was significantly lower than that of the control group.

[0055] The movement trajectories of rats in the simulated microgravity group and the control group were plotted in a two-dimensional open field free exploration paradigm device for 28 consecutive days, such as... Figure 6 As shown in Figure A, it can also be seen that there are changes in the motion trajectory diagrams of the simulated microgravity group and the control group. For the simulated microgravity group (after 28 consecutive days) Figure 6 SM) and control group ( Figure 6 Analysis of the movement speed of CON rats in a two-dimensional open field free exploration paradigm device revealed that the movement speed of rats in the simulated microgravity group was significantly lower than that of the control group. Figure 6 As shown in B.

[0056] Thermograms of cell firing rate in partial hippocampal locations were collected daily from rats in the simulated microgravity group and control group within a two-dimensional open field free exploration paradigm device. The thermograms for cell firing rate on days 1, 7, 14, 21, and 28 are shown below. Figure 7 As shown in Figure A, the peak discharge rate PF (Hz) and location domain area PFS (cm²) of the cell discharge rate heatmap are marked. 2 Spatial information rate SI (Hz / spk). Peak discharge rate and average discharge rate are obtained from the cell discharge rate heatmap, such as... Figure 7 B and Figure 7 As shown in Figure C, by comparing the peak discharge rate and average discharge rate of hippocampal position cells in rats under simulated microgravity and in the control group for 28 consecutive days, it was found that the peak discharge rate and average discharge rate of hippocampal position cells in the simulated microgravity group were significantly lower than those in the control group. This indicates that in the two-dimensional open field free exploration paradigm device, the excitability of hippocampal position cells in rats under simulated microgravity was lower than that in the control group.

[0057] Heatmaps of cell firing rates in partial hippocampal locations were collected daily from rats in the simulated microgravity group and control group within a three-dimensional behavioral box free exploration paradigm. The heatmaps for cell firing rates on days 7 (week 1), 14 (week 2), 21 (week 3), and 28 (week 4) are shown below. Figure 8 As shown in Figure A, the peak discharge rate PF (Hz) and location domain area PFS (cm²) of the cell discharge rate heatmap are marked. 2 Spatial information rate SI (Hz / spk). Peak discharge rate and average discharge rate are obtained from the cell discharge rate heatmap, such as... Figure 8 B and Figure 8 As shown in Figure C, by comparing the peak discharge rate and average discharge rate of hippocampal position cells in rats under simulated microgravity and in the control group for 28 consecutive days, it was found that the peak discharge rate and average discharge rate of hippocampal position cells in the simulated microgravity group were significantly lower than those in the control group. This indicates that under the free exploration paradigm of the three-dimensional behavior box free exploration device, the excitability of hippocampal position cells in the simulated microgravity group was lower than that in the control group.

[0058] Based on hippocampal position cell firing analysis, we studied the coding pattern to enable the research on spatial information representation in rats under different spatial dimensions, and to explore the impact of simulated microgravity on the spatial cognitive ability of rats under different spatial dimensions.

[0059] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A device for free exploration of different spatial dimensions based on rich information, characterized in that, This study investigates the effect of simulated microgravity on the spatial information encoding ability of rats during free exploration in different spatial dimensions with rich information, and explores the underlying neural mechanisms. The free exploration devices in different spatial dimensions include: a one-dimensional ring-shaped unidirectional free exploration device, a two-dimensional open field free exploration device, and a three-dimensional behavior box free exploration device. The one-dimensional ring-shaped unidirectional free exploration paradigm device includes: a ring track and a first rich information (4), the first rich information (4) being fixed on the base plate (1) of the ring track; The two-dimensional open field free exploration paradigm device includes: a cube-shaped cavity (5) with an open top surface, and second rich information (6) is randomly and sequentially fixed on the bottom surface inside the cube-shaped cavity (5). The three-dimensional behavior box free exploration paradigm device includes: behavior box (7), third enrichment information (8) and hanging rod (10). The behavior box (7) is a cuboid box with an opening (9) on the top surface of the cuboid box. The hanging rod (10) is installed inside the behavior box (7). The third enrichment information (8) is fixed on the bottom surface and the inner side wall of the behavior box (7). The hanging rod (10) is fixed at the lower part of the center position of the top surface of the behavior box (7). The hanging rod (10) is used to suspend rats to simulate microgravity modeling.

2. The device for free exploration of different spatial dimensions according to claim 1, characterized in that, The opening (9) is located at the center of the top surface of the rectangular box.

3. The device for free exploration of different spatial dimensions according to claim 2, characterized in that, The ring track includes an outer solid regular M-sided ring structure (2) and an inner solid regular M-sided ring structure (3). The outer solid regular M-sided ring structure (2) is a regular M-sided prism formed by M first side plates, and the inner solid regular M-sided ring structure (3) is a regular M-sided prism formed by M second side plates. The bottom edge length of the first side plate is greater than the bottom edge length of the second side plate. The outer solid regular M-sided ring structure (2) is fitted outside the inner solid regular M-sided ring structure (3) and the two are concentrically arranged. The bottom edge of the outer solid regular M-sided ring structure (2) and the bottom edge of the inner solid regular M-sided ring structure (3) are connected by the bottom plate (1) so that the outer solid regular M-sided ring structure (2) and the inner solid regular M-sided ring structure (3) form the ring track.

4. The device for free exploration of different spatial dimensions according to claim 3, characterized in that, Both the first and second side panels are rectangular.

5. The device for free exploration of different spatial dimensions according to claim 4, characterized in that, The first rich information (4) is randomly fixed on the base plate (1).

6. The device for free exploration of different spatial dimensions according to claim 1, characterized in that, The first enrichment information (4), the second enrichment information (6) and the third enrichment information (8) respectively include objects of different colors and shapes, which are used to enrich visual and tactile information.

7. A method for a free exploration paradigm based on rich information in different spatial dimensions, comprising the following steps: The rats were subjected to a formal experiment for N days using the free exploration paradigm device of different spatial dimensions as described in any one of claims 1 to 6. During the formal experiment, the rats were subject to food restriction each day. The experiment each day included S1-1, S1-2, and S1-3 in sequence, with the rats resting for at least 3 minutes between S1-1, S1-2, and S1-3. S1-1: Place rats on the circular track of a one-dimensional ring-shaped unidirectional free exploration paradigm device for two unidirectional free explorations. After each unidirectional free exploration, the rats are removed from the circular track and allowed to rest for at least 3 minutes. During each unidirectional free exploration, the rats are rewarded with food at least once. If the rats stop exploring, food is placed at random locations on the circular track as a reward to encourage them to continue exploring until the circular track is completed. S1-2, rats were placed in a two-dimensional open field free exploration paradigm device and allowed to begin a 10-minute free exploration period. After the free exploration ended, the rats were removed from the two-dimensional open field free exploration paradigm device. During the free exploration, the rats explored freely for the first 5 minutes, and food was placed at random locations in the two-dimensional open field free exploration paradigm device as a reward for the last 5 minutes, encouraging the rats to explore the entire area of ​​the two-dimensional open field free exploration paradigm device. S1-3, the rat was placed in the three-dimensional behavior box free exploration paradigm device and suspended from the hanging bar in the three-dimensional behavior box free exploration paradigm device, allowing the rat to begin a 10-minute free exploration.

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