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Six major neurotransmitters in the brain their function

Yakobchuk Definition Neurotransmitters are chemicals located and released in the brain to allow an impulse from one nerve cell to pass to another nerve cell.

Description There are approximately 50 neurotransmitters identified. There are billions of nerve cells located in the brain, which do not directly touch each other. Nerve cells communicate messages by secreting neurotransmitters. Neurotransmitters can excite or inhibit neurons nerve cells. Some common neurotransmitters are acetylcholine, norepinephrine, dopamine, serotonin and gamma aminobutyric acid GABA.

  1. For vertebrates, the brain is located in the head and at close proximity senses like taste, sight, smell, hearing, and balance.
  2. This centralizes all functions of the nervous system.
  3. Dopamine is strongly associated with reward mechanisms in the brain.

Acetylcholine and norepinephrine are excitatory neurotransmitters while dopamine, serotonin, and GABA are inhibitory. Each neurotransmitter can directly or indirectly influence neurons in a specific portion of the brain, thereby affecting behavior. Mechanism of impulse transmission A nerve impulse travels through a nerve in a long, slender cellular structure called an axon, and it eventually reaches a structure called the presynaptic membrane, which contains neurotransmitters to be released in a free space called the synaptic cleft.

Freely flowing neurotransmitter molecules are picked up by receptors structures that appear on cellular surfaces that pick up molecules that fit into them like a "lock and key" located Neurotransmitters are chemicals that transmit messages from one nerve cell neuron to another. The nerve impulse travels from the first nerve cell through the axon—a single smooth body arising from the nerve cell— to the axon terminal and the synaptic knobs.

Neurotransmitters

Each synaptic knob communicates with a dendrite or cell body of another neuron, and the synaptic knobs contain neurovesicles that store and release neurotransmitters. The synapse lies between the synaptic knob and the next cell. For the impulse to continue traveling across the synapse to reach the next cell, the synaptic knobs release the neurotransmitter into that space, and the next nerve cell is stimulated to pick up the impulse and continue it.

Once the neurotransmitter is picked up by receptors in the postsynaptic membrane, the molecule is internalized in the neuron and the impulse continues.

This process of nerve cell communication is extremely rapid. Once the neurotransmitter is released from the neurotransmitter vesicles of the presynaptic membrane, the normal movement of molecules should be directed to receptor sites located on the postsynaptic membrane. However, in certain disease states, the flow of the neurotransmitter is defective.

For example, in depression, the flow of the inhibitory neurotransmitter serotonin is defective, and molecules flow back to their originating site the presynaptic membrane instead of to receptors on the postsynaptic membrane that will transmit the impulse to a nearby neuron.

Description

The mechanism of action and localization of neurotransmitters in the brain has provided valuable information concerning the cause of many mental disorders, including clinical depression and chemical dependency, and in researching medications that allow normal flow and movement of neurotransmitter molecules. Neurotransmitters, mental disorders, and medications Schizophrenia Impairment of dopamine-containing neurons in the brain is implicated in schizophreniaa mental disease marked by disturbances in thinking and emotional reactions.

Medications that block dopamine receptors in the brain, such as chlorpromazine and clozapinehave been used to alleviate the symptoms and help patients return to a normal social setting. Depression In depression, which afflicts about 3.

Depression is treated with antidepressants that affect norepinephrine and serotonin in the brain. The antidepressants help correct the abnormal neurotransmitter activity.

A newer drug, fluoxetine Prozacis a selective serotonin reuptake inhibitor SSRI that appears to establish the level of serotonin required to function at a normal level. As the name implies, the drug inhibits the re-uptake of serotonin neurotransmitter from synaptic gaps, thus increasing neurotransmitter action.

In the brain, then, the increased serotonin activity alleviates depressive symptoms. Alzheimer's disease Alzheimer's diseasewhich affects an estimated four million Americans, is characterized by memory loss and the eventual inability for self-care.

  • Description There are approximately 50 neurotransmitters identified;
  • Dopamine is strongly associated with reward mechanisms in the brain;
  • In the brain, then, the increased serotonin activity alleviates depressive symptoms;
  • Opiates, such as heroin and morphine, appear to mimic naturally occurring peptide substances in the brain that act as neurotransmitters with opiate activity called endorphins.

The disease seems to be caused by a loss of cells that secrete acetylcholine in the basal forebrain region of brain that is the control center for sensory and associative information processing and motor activities. Some medications to alleviate the symptoms have been developed, but presently there is no known treatment for the disease.

Generalized anxiety disorder People with generalized anxiety disorder GAD experience excessive worry that causes problems at work and in the maintenance of daily responsibilities.

Six major neurotransmitters in the brain their function

Evidence suggests that GAD involves several neurotransmitter systems in the brain, including norepinephrine and serotonin. Research shows that dopamine and norepinephrine imbalances are strongly implicated in causing ADHD.

Others Substantial research evidence also suggests a correlation of neurotransmitter imbalance with disorders such as borderline personality disordersschizotypal personality disorderavoidant personality disordersocial phobiahistrionic personality disorderand somatization disorder. Drug addictions Cocaine and crack cocaine are psychostimulants that affect neurons containing dopamine in the areas of the brain known as the limbic and frontal cortex. When cocaine is used, it generates a feeling of confidence and power.

However, when large amounts are taken, people "crash" and suffer from physical and emotional exhaustion as well as depression.

Opiates, such as heroin and morphine, appear to mimic naturally occurring peptide substances in the brain that act as neurotransmitters with opiate activity called endorphins.

Natural endorphins of the brain act to kill pain, cause sensations of pleasure, and cause sleepiness. Endorphins released with extensive aerobic exercise, for example, are responsible for the "rush" that long-distance runners experience.

  1. Stress tends to deplete our store of adrenalin, while exercise tends to increase it. The other four include Serotonin, Neropinephrine, Dopamine, and Acetylcholine.
  2. The other four include Serotonin, Neropinephrine, Dopamine, and Acetylcholine. However, when large amounts are taken, people "crash" and suffer from physical and emotional exhaustion as well as depression.
  3. Serotonin is a monoamine neurotransmitter produced and found in the gastrointestinal track and the central nervous system of humans.

It is believed that morphine and heroin combine with the endorphin receptors in the brain, resulting in reduced natural endorphin production. As a result, the drugs are needed to replace the naturally produced endorphins and addiction occurs. Attempts to counteract the effects of the drugs involve using medications that mimic them, such as nalorphine, naloxone, and naltrexone. Alcohol is one of the depressant drugs in widest use, and is believed to cause its effects by interacting with the GABA receptor.

Initially anxiety is controlled, but greater amounts reduce muscle control and delay reaction time due to impaired thinking. Laith Farid Gulli, M. Other articles you might like: