Brother Wu always sees that many research institutions, hospitals and universities on the market are buying zebrafish behavior analysis equipment, so what exactly are these devices used for?
First of all, just like studying human behavior, you must have a video camera, and use the camera to record all the behaviors that occur, so that you can follow up and study.
In the process of research, there will also be many research models.
The so-called open field test (Open field test), also known as the square test, is to put the zebrafish into a fixed-size fish tank, so that the fish swim freely in the fish tank, the whole process is timed, and then use the camera to record the movement trajectory of the fish. The analytical instrument will calculate a lot of data based on this, including the time the fish stays in the central area and the outer wall area of the fish tank, the average swimming speed of a fish and the total length of swimming, which are usually applied to some subsequent studies to express a certain state, such as the activity of the fish.
The above test method usually records the perspective from top to bottom, and then another perspective, such as observing the fish tank from both sides, and can record the fish swimming from the bottom to the middle layer, and finally swimming to the upper level. The data obtained this time can also be used as a test of the preference of different fish species for the selection of water layers.
There is also a type of test called the Novel object test. The test principle is simple, that is, to place different objects in the fish tank, and then observe the zebrafish's reaction to these objects, such as putting an orange square on the side of the fish tank, or throwing a waterproof horn into an area to play heavy metal music, or smearing a little chili sauce somewhere in the fish tank. The purpose of this experiment is more open, usually to test the degree to which zebrafish react to the external environment, especially objects. All records may be recorded by the speed, distance, and trajectory of the fish, and should be able to judge the zebrafish's preference and dislike for something, so this is a kind of experiment that is more carried out in the laboratory.
The social test is also a very important test. The specific principle is to put two fish in a cross-shaped glass trough, one fish in the center of the cross, and the other fish randomly placed on the top of one of the four sides, and then observe the trajectory of the fish, record the overlapping route of the two fish, and the degree of proximity. This test can also be used between different species to see which types of fish are more social and which prefer to live alone.
Light and noise tests are also a relatively large number of test types, mainly used to test the zebrafish's response to these two external stimuli.
However, the most interesting test is the maze test. The principle of the test is simple, that is, arrange a maze between the two fish tanks, place food in one side of the fish tank, and induce the fish to enter the maze from one side of the fish tank to find food. After the test is initiated, the time when the fish successfully find food is recorded to examine the memory ability of different individuals of the same fish, or between different fish.
Of course, what the fifth brother can't bear to mention is that the zebrafish behavior test is also included in the toxicological test.
As we all know, some psychotherapeutic drugs or some special solids and gases will trigger different human behaviors, such as laughing gas nitrous oxide. Zebrafish behavior testing can detect the effects of some harmful substances on water quality and aquatic animals.
In fact, this test is also relatively simple, such as allowing zebrafish to carry out routine mating, reproduction, embryonic development, growth, etc. in the water quality with insecticides added, recording the behavior of zebrafish throughout the process, and comparing it with the living behavior of zebrafish living in normal water quality, thus discovering the impact of harmful substances.
In fact, like people in unfamiliar forests, the two most common behaviors of zebrafish are searching and ambushing. The biggest difference between the performance of these two behaviors is in two aspects, one is the distance of the activity, and the other is the posture of swimming.
Because of the high transparency of the zebrafish embryonic brain, people can even study the relationship between behavioral occurrence and nerve cell state from a deeper dimension. Through the microscope, people can clearly count the number of nerve cells involved in a certain behavior, and even locate the movement of each cell, which lays the foundation for describing behavior with cells.
This has a deeper meaning, that is, to achieve artificial control of the zebrafish's behavior, because as long as you know which nerve cells, make those actions, leading to the zebrafish's related behavior, you can, all of this series of processes, can be programmed to form instructions, used to guide the zebrafish to continue to carry out a certain behavior.
Visual behavioral testing is often combined with deep organ and even cell-level fluorescent markers to form a more three-dimensional research system.
For example, recent scientists' research on the memory process of zebrafish is carried out by allowing zebrafish to receive sound and light stimulation, and then recording the motor state of brain neurons. This is a pattern of behavioral testing that is both internal and external, and the scope of its meaning and conclusions will be expanded.
This is also an obvious advantage, because no one can see how memory is realized, but memory is happening in humans or in other animals all the time. The transparency of zebrafish embryos has helped scientists subvert their understanding of traditional memory processes, arguing that memory may take many more forms, including previously widely accepted connections between neuronal axons and the newly discovered results of neuronal recombination and solidification.
On the day of March 9, the fifth brother heard the sad news that the world's first patient to receive a pig heart transplant had passed away. So what the fifth brother thought was, why didn't the doctor use zebrafish to test the tolerance of the pig's heart first? Perhaps, when the doctor performs gene editing for the donor pig, such as knocking out the gene that triggers the immune rejection reaction and a pig gene that causes the heart tissue to overgrow, it may have increased the success rate of the entire transplant process a lot, but from the current results, there should be some genes that need to be knocked out or replaced that have not been treated as they should be, so before the final transplant operation, using zebrafish or other model organisms is expected to help find other genes that have not been processed, which is very important. Although it will take too long. Of course, perhaps this transplant program faces some extreme conditions, such as the patient's own vital signs, the predetermined situation of surgical resources, etc., which will affect the final result.
Gene editing is actually always tightly tied to zebrafish-related research. About 3 years ago, scientists conducted a pathological study of inflammatory bowel disease, which involved two scenarios, namely the in vivo scene and the in vitro scene. The in vivo scenario is to obtain zebrafish prone to inflammatory bowel disease through gene editing, and the in vitro scene is to extract pathogenic genes from the body of the diseased zebrafish for research in in vitro inhibition environment. Both scenarios will be adopted on a large scale thereafter, especially as screening drugs for inflammatory bowel disease treatments.
There are many more cases for zebrafish behavioral studies. In most cases, it is related to humans, and people have found out the laws of human behavior from the behavior display of zebrafish, and then applied various possibility tests. Earlier, the five brothers had heard that zebrafish would be placed in the water where heroin was present to observe the behavior of zebrafish after being contaminated with drugs. That's right! It is equivalent to letting zebrafish take drugs and become addicted to drugs. But this is certainly not the ultimate goal, and scientists will continue to see if there are potential drugs that can help zebrafish quit drugs and regain their health, and these advantages seem to be not available to other mode organisms such as nematodes, grasshoppers, E. coli, fruit flies, yeasts, etc. If you had to emphasize to me that this fish has no lungs and no breasts, then the fifth brother really has nothing to say.
The fifth brother just hopes that everyone can know about this cute little fish that is dedicated or is dedicating itself to human health. Brother Wu heard that a member of a scientific research team had habitually added a page of PPT specially made to thank zebrafish for their contributions every time they introduced relevant research results.
Good! The five brothers also do it here: salute to the zebrafish!
Column about the raw five brother zebrafish
The fifth brother began to pay attention to zebrafish in 2021, and when he first came into contact with this small fish, he was deeply shocked by its elf-like figure, universal research value, and tenacious vitality. The fifth brother believes that this is a great fish that deserves to be praised and sung by people, so the fifth brother is willing to become a member of thousands of praisers in China, constantly learning it, studying it, explaining it, spreading it, so that more people like it, pay attention to it, and join this new and very meaningful thing. Therefore, the five brothers have also established such a column on today's headlines, welcome more people of insight to discuss with the five brothers, but also welcome friends to pay attention to this column, what want to understand the topic can also be directly in today's headlines private message five brothers. Of course, the fifth brother is not a divine horse expert, and the fifth brother is only a small fan of the zebrafish junior, and all the discussions are the process of communicating and learning with everyone.