An explanation of Neurotransmitters

Sleep Disorders

An explanation of Neurotransmitters

This website covers all aspects of sleep; neurotransmitters are involved in sleep, waking, and the transitions between them. Brain chemistry is very complicated and scientists don't totally understand how all the pieces fit together. Here we give a short description of major neutrotransmitters.

Neurons (commonly called nerves) are a unique and specific type of cell found in the body and the brain that carries electrical information between cells. To put it simply, their job is to receive a signal from a cell, convert it to an electric signal called an action potential and transmit this electric signal to another cell that could also be another neuron. When they need to communicate to another cell or neuron, the first neuron sends a chemical called a neurotransmitter across the space between the two, over to the next cell. Once at the second cell, the neurotransmitter binds to a receptor, telling the second cell what to do or telling another neuron if to send a signal and whether it should be a strong or a weak signal.

A few examples of signals neurotransmitters are responsible for are spinal reflexes and sleep regulation. For almost all body functions, there is a corresponding neurotransmitter controlling it. There are currently conflicting classifications of which chemicals in the brain are considered to be neurotransmitters by definition. To avoid confusion, it is best to stick to the neurotransmitters that carry the largest workload and that scientists agree are actually neurotransmitters.

GABA (gamma aminobuytric acid) is an amino acid derivative that acts as an inhibitory neurotransmitter, preventing or reducing certain nerve signals. It controls nervous signals in the retina and the central nervous system, so insufficient GABA usually causes anxiety and even epileptic seizures. There are synthetic drugs that can temporarily increase the GABA levels and in turn reduce anxiety, and offer anti convulsive effects. Some medicinal and recreational drugs reduce the natural level of GABA; these include alcohol, barbiturates and cannabinoids. These drugs that reduce GABA combined with serotonin depletion can cause depression that keeps addicts in the cycle of addiction. Patients with spastic cerebral palsy have damaged nerves in the central nervous system that cannot properly absorb GABA, affecting motor or muscular skills.

Glutamic acid, also known as glutamate, is an amino acid and is the most common neurotransmitter in the body. Glutamate’s most vital function as a neurotransmitter is in cognitive activities like memory and learning. Scientists have pointed the finger at glutamic acid as being involved in epileptic seizures, probably since glutamate can also be a precursor for the synthesis of GABA.

Acetylcholine was the first neurotransmitter to be discovered by scientists and its major function is in the voluntary movement of muscles, though it also has many other functions. It is implicated as being involved in the scheduling of REM sleep and in the onset of Alzheimer’s disease when some regions of the brain have depleted acetylcholine.

Norepinephrine is the neurotransmitter most involved in the “fight or flight” response and other stressful situations, since it increases heart rate and blood pressure. It is known for causing arousal or wakefulness, attentiveness, sleep, dreaming and it is also involved in the formation of memories. Scientific studies have shown that in some mood disorders, elevated norepinephrine may be responsible for some or all of the symptoms.

Dopamine is another inhibitory neurotransmitter involved in voluntary movement and motivation. Alcohol, nicotine and some recreational drugs increase the level of dopamine. Schizophrenia is linked to elevated levels of dopamine in the frontal lobes of the brain. Conversely, low levels of dopamine in the motor areas of the brain are responsible for Parkinson’s disease, causing muscle rigidity and uncontrollable muscle tremors. Animal models of Parkinson's disease and schizophrenia have found that dopamine plays an important role in regulating sleep.

Serotonin is involved in several important body functions such as memory, emotions, moods, sleep and arousal. Serotonin deficiencies have been linked to depression, anger, OCD, sleep disturbances, irritable bowel syndrome and many other emotional and physical disturbances.

The study of neurotransmitters and how they work will very likely lead to treatments of nervous system disorders, depression and possibly even diseases like Alzheimer’s. Research on neurotransmitters is illuminating the causes of and necessary treatments for chemical addictions. Neurotransmitters are vital for the smooth functioning of the brain and body. The impressive tasks constantly performed by our neurotransmitters obviously hold more answers than we can possibly imagine.

Medications for insomnia and hypersomnia usually act on neural systems and effect, in some manner, neurotransmitters. Sleep aids tend to work on the GABA receptors in the brain, or melatonin receptors. Stimulants usually work on dopamine or acetylcholine systems.

More on neurotransmitters - Indiana State University

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