This causes the nerve cell to fire, sending an electrical impulse along the nerve. When bradykinin is released near the skin, a second chemical, called substance P, is released near the spinal cord. Both substances are known to be involved in transmitting pain. For example, if bradykinin is injected into humans, it causes intense pain, even if a local anaesthetic is used. Both bradykinin and substance P are found in mammals, birds, frogs and fish.
Fish produce the same pain-blocking substances as humans.
These endorphins block pain by stopping the release of substance P. Fish Feel Anxiety For any chemical to be able to affect our brain, there must be special areas in the brain, called receptor sites, to which the chemical can attach. Fish, like mammals, have receptor sites for anxiety-reducing chemicals, such as the valium group of drugs. What YOU Can Do Choose ways of relaxing and enjoying the outdoors that do not cause suffering to animals. If people you know won't give up fishing, at least try to convince them to kill fish as soon as they are pulled from the water, rather than removing hooks while they are still alive and letting them suffocate.