Dopamine is a neurotransmitter, one very important to the body. A neurotransmitter is a chemical that is used to send messages through the body through nerve cells. Dopamine is a neurotransmitter that affects movement, behavior, learning, emotions, and feelings, most commonly pleasure. Dopamine is produced mainly in the brain, and is released at certain times to help with the body’s emotional and physical functions. Dopamine works in different areas for different situations. There is a part of the brain called substantia nigra that has neurons that make dopamine. The other place, one less defined, is the ventral tegmental area (VTA). This part is more focused on pleasure. If the dopamine level is not balanced, disorders will most likely occur. If dopamine is not balanced, than more or less is needed to normalize body functions. Dopamine, as a neurotransmitter, travels in between nerve cells. Nerve cells have their own cell body, and around the body are branches of nerve fiber. Around the axon in small cylinder-like wrappings is different tissue called the myelin sheath. At the end of the axon is small gap called the synapse. The synapse is the bridge between nerve cells that transfers the information.
The synapse is made of three parts: the presynaptic ending, where the neurotransmitters are, along with some other cell organelles; the postsynaptic ending is the part that receives what the presynaptic ending lets go and the postsynaptic ending can be another axon, a dendrite, or a cell body. Then the synaptic cleft, which is the space in between the presynaptic and postsynaptic endings. What happens is that the neurotransmitter is created in the nerve cell, and travels by a vesicle. The vesicles store the neurotransmitters when they receive them from the cell body and move to the presynaptic ending when an electric impulse is sent through the cell, which acts like an activation code. The vesicles release the transmitters through the ending. The transmitters are then received by receptors on the postsynaptic end, and there the neurotransmitter releases signals, causing the message to be sent through the body. When the message is not carried on through the nerve cells, a disease can occur. Drugs and medicine can be used to cure this. In the brain, the part substantia nigra, has neurons that produce dopamine. If those neurons die or there are too few of them, there is less dopamine in the body. There is a disorder that occurs when there is not enough dopamine, called Parkinson’s disease.
Without the dopamine, cells cannot communicate effectively with each other. This causes slow, difficult movements, tremors, shuffling, and muscle rigidity. Elderly are more affected by this, but around one million Americans have it. Although there is no definite way to cure, there is a way to lower the effects. That is done through a medicine called Levodopa. Levodopa is a chemical, and our bodies can change it to dopamine. This slows the progression of the disease and reduces symptoms, but does not stop it. Scientists and doctors are still looking for the cure. Lack of dopamine might also cause depression. While lack of dopamine is a problem, too much dopamine can also cause a problem. Excess dopamine is a possible cause of schizophrenia. Schizophrenia is a form of psychosis or loss of contact with reality. It can also be caused by excess of dopamine receptors. Receptors are proteins that allow cells to send information. Treatments for schizophrenia usually decrease dopamine in the brain, either by lowering the dopamine released, or by stopping some of the receptors. This sometimes causes Parkinson disease symptoms, when too much dopamine is blocked.
The drugs are called dopamine antagonists. Excess dopamine can also cause psychotic depression, or even Tourette syndrome. The other part of the brain that contains dopamine neurons is the ventral tegmental area. This area is more related to the pleasure effect of dopamine. VTA neurons release dopamine when something good happens. “Good” can be described as the presence of food, a present, or something else that makes you happy, or even when you are satisfied. It can also be when you are in pain, and you get relief from the pain, or you are stressed about something, and everything turns out okay. Dopamine gives a feeling of pleasure. This feeling is given after a particular action. Thus, a person will repeat the action to get that good feeling. Like when you eat something good, you will eat the same thing over and over to get that rush. The pleasure can be given after being satisfied, like when you are trying to get information and when you get it, you feel satisfied. This causes you to think- information=satisfaction=happiness, so you seek far more information then you need. This is how desire for something happens, and to satisfy that desire repeatedly, addiction begins.
Dopamine also plays a key part in organisms adapting to environments and surviving. It pushes them to try and survive, because survival is good. Survival means good health. Dopamine causes animals and humans to try and see patterns. When a reward is given, the animal or human will try to figure out what exactly got the reward, and how to get it again. When figured out, the action will be repeated, and leads to happiness. This helps people survive and adapt, but can make people get hurt and fail. Either way it is important.
Dopamine is vital to our existence. It helps us survive by pushing us to adapt. It controls many major functions in our body, like emotional and physical, but a one main part is the pleasure feelings. It is what makes us elated and depressed, satisfied or desiring. Dopamine can cripple us, too. It is not always good. It is most of what causes addictions; when released, it gives the body a pleasant feeling. Dopamine is released when something good happens.
When something good does happen, that good thing is repeated over and over until it becomes addiction. The addiction is usually harmful, and can be life-threatening. It is also what makes people take risks, gamble, and defy authority. Too much of it can cause make a schizophrenic, which is someone with messed up brain functions, and too little can cause Parkinson Disease, which messes with motor skills and balance. This is because of dopamine’s large role in our body and mind. Dopamine is a very important neurotransmitter, and it travels along the nerve cells of the body to give messages. It is in two main parts of the brain, the ventral tegmental area, and the substantia nigra. It controls a lot of our body, and is necessary for humans and animals to survive.
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