Hardware requirements for the Morris water maze

1. Pool and platform:

For the size of the pool, there is a problem of artificial choice. It seems that it should be uniform. It is not easy. But there is a principle that the pool should not be too small and the platform should not be too big. Morris originally (1981) used a rat pool of 1.32 meters in diameter and 0.6 meters in height, and the depth of the pool was 0.40 meters; but later (1984) changed to a diameter of 2.14 meters and a height of 0.4 meters, and the depth of the pool was 0.25. Meter. For experimental pools in mice, the labyrinth diameters described in the literature vary widely, from as small as 0.6 meters to as large as 2.0 meters. In general, too small a pool increases the chance of a mouse climbing onto a platform and reduces the difficulty of the task. An oversized pool will prolong the swimming path of the mouse, consume too much physical strength, and reduce the chance of climbing the platform. Most of the labyrinth pools used in the domestic literature are mostly 1.6m or 1.8m in rats, while mice are generally 1m or 1.2m and 0.5m high. The platform is generally circular, and the diameter can be divided into 12 cm in rats and 6 cm in mice. The surface is rough and the height is generally 30 cm. The labyrinth pools used in foreign literature are mostly 1.8m or 2.0m in rats, 0.6m in height and 10cm in diameter. The mice are generally 1m to 1.5m in height and 0.3m in height and 5cm in height. Can domestic size be unified? How to set the standard?

2. Water temperature:

The temperature of the water requires constant temperature during the experiment. The temperature range of rats is generally 25 ± 1 °C, and the mice may be lower at 18-22 °C. It has been reported in the literature that the effect of water temperature on maze performance was observed in mice. The results showed that the mice in the 27~28°C group had the worst scores, while the scores in the 17~18°C group and the 21-22°C group did not differ. Therefore, we recommend the experiment of mouse water maze with 21~22 °C water. The water temperature has a great influence on the incubation period, especially in rats. If the temperature is too high, the rat gradually adapts to the labyrinth environment after a few swims. It will use the maze as a "bathtub". After being put in, it will float. If the water temperature is too low, the body temperature of the rat will drop rapidly, and the physical strength will be dissipated too much. The swimming ability of the rat can not be maintained for a long time, and there will be a sudden increase in the incubation period. Even some mice have a more obvious stress response, such as cramps and diarrhea. The water temperature is generally maintained at about 25 degrees. In addition, the temperature will cause the water temperature to deviate too much. The water temperature should be adjusted artificially. Therefore, it is required to have a constant water temperature at the bottom of the pool.

3. Light source:

To ensure that there is no light and shadow on the water surface of the pool, it is mainly to avoid the reflection of light on the water surface, so as to avoid the shadow of the light left on the surface of the water being confused with the shadow of the mouse by the software collection system; if it is a white pool background, it can be in the pool. Use two strips of divergent fluorescent light on the top to reduce the back of the reflected light on the water surface; if it is a black pool background, place four 60-watt bulbs or 25-watt tube lights above the four quadrants of the pool. A particularly powerful lamp. The height of the bulb should be high enough to be captured by the camera. In addition, you can also install a curtain around the pool (the color is generally black, light blue or white), which can block the shadow of light and maintain a certain degree of transparency. At the same time, it can also reduce the presence of people outside the pool or walk around, forming an indefinite spatial reference for the rats.

4. Spatial cues (reference objects):

The pool should be placed in a larger room with more than two objects suspended as a close-range visual reference and a variety of remote visual references in the room outside the pool. For example, geometric figures (squares, triangles, circles, etc.) hang from the wall outside the pool. The height is the range that must be seen when the big mouse is swimming, so it should be above its horizon, these geometric figures can be Made of 5cm to 15cm wide plastic sheets, the height must be higher than the platform, and can be hung around the pool with a 1m line; these geometric shapes are generally painted black, because rodents are more sensitive to black; these geometric figures are generally not less than 3 In addition, the laboratory environment is a very important factor. The location of the laboratory equipment, instruments, workbench, chairs, doors and windows, and lamps and the position where the experimenter is standing during the experimental operation may be seen by the big mouse. Will affect the experimental results. Because animals sometimes use the environment inherent in the laboratory as a reference for their search targets.

Anthocyanin

Anthocyanins widely exist in flowering plants (angiosperms), and their content in plants varies greatly with varieties, seasons, climate and maturity[ 5] According to preliminary statistics, anthocyanins are contained in 27 families and 73 genera, such as purple sweet potato, grape, blood orange, red ball cabbage, blueberry, eggplant, cherry, red berry, strawberry, mulberry, hawthorn, morning glory and other plant tissues. Anthocyanins are mainly used in food coloring, dyes, medicine, cosmetics and so on.