What are Neurotransmitters?

of the chemical messenger dopamine, which affects parts of the brain that control reward and

Experts believe bipolar disorder is caused by an underlying problem with specific brain circuits and the balance of brain chemicals called neurotransmitters (WebMD). There are five brain chemicals noradrenaline (norepinephrine), serotonin, dopamine, oxytocin, and endorphin. Noradrenaline and serotonin are the most common chemicals linked to psychiatric mood disorders such as depression and bipolar (WebMD). Dopamine is linked to the pleasure system in the brain (WebMD). When a disruption happens to the dopamine system connects to psychosis and schizophrenia (WebMD). If there is too much dopamine in one place, it can cause psychosis. Dopamine motivates us (Deans, 2011). Dopamine is linked to everything, metabolism, evolution, and the brain (Dean, 2011). Serotonin is connected to many different body functions including sleep, wakefulness, eating and impulsivity (WebMD). Researchers believe that abnormal brain functioning of brain circuits that involve serotonin as a chemical messenger contributes to mood disorders (WebMD). Oxytocin is a hormone commonly associated with childbirth and breastfeeding. Oxytocin plays a critical role in social and emotional behavior. Oxytocin increases the susceptibility to feeling fearful and anxious during stressful events (NWU, 2013).

Dopamine: This chemical controls body movements. Lack of dopamine means you will no longer be able to control your movements very well. Dopamine also controls the transportation of information

A neurotransmitter is a chemical messenger that travels across the synapse between a neuron and another neuron, muscle fiber, or gland. Hormone is a chemical messenger of the endocrine system that is released by a gland or organ and travels through the blood. Neurotransmitter and hormone both compare because they both are chemical messenger, both chemicals are released from vessels into the surrounding fluid by similar mechanisms. They both work by binding to receptors on target cells. Neurotransmitter and hormones are very important systems, which regulate the various activities of the body, and are dependent on the release of special chemicals. Furthermore, the tissues in the Central Nervous System produce some hormones, as well as the neurotransmitters. What sets neurotransmitter and hormone apart? Neurotransmitters belong to the nervous system, however hormones belong to the endocrine system. Hormones and neurotransmitters are engendered differently; hormones are engendered by endocrine glands while neurotransmitters are engendered by neurons. The transmission of neurotransmitters is across the synaptic cleft, whereas that of hormones is by blood. Hormones are able to regulate their target organs, whereas neurotransmitters are able to stimulate the postsynaptic membranes. The action of neurotransmitters is extremely fast, which could be up to a few milliseconds. In contrast, effect of hormones could be lost for a long period, which could be in the range of few seconds to a few days.

The brain uses neurotransmittors to tell your stomach to digest and your heart to beat. Neurotransmittors are also responsible for balancing mood, sleep, and even weight. If the chemicals in our brain become out of balance, we can suffer sever adverse affects that make life both challenging and debilitaing as we strive to function.

The role of serotonin on the mood of depressed patients is not fully understood. Studies show that a shortage of serotonin affects an area of brain that predominates emotions: the amygdala. (2) This almond-shaped brain region connects emotions to our sensory perceptions and appears particularly important in the formation of negative emotions. A lack of serotonin makes the amygdala more susceptible to sensory stimuli. In an experiment where they temporarily lowered serotonin levels in the brain in healthy subjects, they recorded a stronger reaction of the amygdala. (3) Foreign studies confirm this role of amygdala during depression.

Some dopaminergic (i.e., dopamine-releasing) neurons run from the substantia nigra to the corpus striatum; their loss gives rise to the clinical manifestations of Parkinson's Disease (Korczyn 1994); others, involved in the rewarding effects of drugs and natural stimuli, run from the mesencephalon to the nucleunucleus accumbens.

Serotonin, (or 5-hydroxytryptamine) is a neurotransmitter released by neurones in the brain. It is a chemical responsible for good mood and well-being. Therefore one of the possible causes of depression is a chemical imbalance of Serotonin levels in the brain and consequently, ineffective neuronal transmission at the synaptic cleft. (Lovatt, 2010) This has negative implications on mood, sleep and appetite.

However recent research shows that the process is more complicated. Dopamine is not only related to pleasure but also to learning and memory, key components in going from liking a substance to becoming addicted to it. According to this theory it is believed that dopamine combines with another neurotransmitter, glutamate, to take over the brain’s system of reward related learning. This system plays an important role in sustaining life by linking such activities as eating and sex with pleasure and reward.

Studies also show, a decrease in the ability of the Attention Deficit Disorder brain to use glucose, the body's main source of energy, leading to slower and less efficient activity. Neurotransmitter provide the connection between one nerve cell and another. It is also now suspected that people with Attention Deficit Disorder have a chemical imbalance of a class of neurotransmitter called catecholamine. Dopamine, helps to form a pathway between the motor center of the midbrain and the frontal lobes, as well as a pathway between the limbic system and the frontal lobes. Without enough dopamine and related catecholamine, such as serotonin and norepinephrine, the frontal lobes are under stimulated and thus unable to perform their complex functions efficiently.

Furthermore Parkinson’s disease, which is associated with a depletion of dopamine display behaviours characteristic of schizophrenia when given too much L-DOPA, a dopamine stimulant (Gershon, Angrist, and Shopsin, 1977 as cited in Kalat, 1992). In addition if schizophrenics are given drugs such as L-DOPA their symptoms are heightened. (Kalat, 1992).

Dopamine establishes different levels of the neurotransmitter in both the dorsa striatal and ventral striatal-prefrontal as dopamine is released. The dopamine released in the ventral striatal determines how strenuously individuals perform repeated tasks over time and the dopamine released in the dorsa striatal determines the speed in which the actions occur (p. 645). According to Luck, Wevrick & Vitaterna (2016) dopamine plays a crucial role in reward-associated behavior such as gambling, drug use, and over-eating, hence the word dopamine is often paired with the term “pleasure system.” Associations with dopamine have been correlated with feelings of enjoyment, pleasure and rewarding experiences and the reward canal is concentrated on dopaminergic neurons located mostly in areas of the midbrains (448-449).

Dopamine is a brain chemical/Neurotransmitter that work as messenger signal between the Substantia Nigra to the next relay station of the brain, the corpus striatum which helps to produce smooth coordinate movement and also plays a major role to help control muscle’s movement. With Parkinson’s disease, the brain cells that produce dopamine slowly die, which lead to decrease production of Dopamine. The loss of dopamine causes abnormal nerve firing with brain and the cells that control muscle’s movement by sending the messages to the muscles; due to this it becomes really hard to control muscles movement and cause tremors and various other symptoms such as rigidity and difficulty walking and performing daily tasks. Dopamine is not the only neurotransmitter involved in Parkinson’s Disease. Norepinephrine is very relatively close to dopamine and is also involved in Parkinson’s Disease. Individuals with Parkinson’s Disease have loss of nerve ending that produce norepinephrine. Norepinephrine is a major neurotransmitter for sympathetic nervous system, which control many autonomic functions of our body; it causes increase in blood pressure and heart rate. Loss of norepinephrine can help us explain the non-motor symptoms associated with Parkinson’s Disease such as fatigue, decrease in gastric stability and disruption in cognition. Parkinson’s Disease can be hereditary

Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter in the brain that has an enormous influence over many brain functions. It is synthesized, from the amino acid L-tryptophan, in brain neurons and stored in vesicles. Serotonin is found in three main areas of the body: the intestinal wall; large constricted blood vessels; and the central nervous system. The most widely studied effects have been those on the central nervous system. The functions of serotonin are numerous and appear to involve control of appetite, sleep, memory and learning, temperature regulation, mood, behavior (including sexual and hallucinogenic behavior), cardiovascular function, muscle contraction, endocrine regulation, and

In the article “Dopamine and Teenage Logic” by Daniel Siegel he states that “Dopamine is a neurotransmitter central in creating our drive for reward” (Source B). This indicates that dopamine is one of the key causes of risk-taking. Teens often take risks because they are focused on the reward they get after they take it, rather than what would actually happen to them during and after they take the risk. There are two significant ways that dopamine affects our brains; increased impulsiveness, and the susceptibility to addiction by the release of dopamine.