The Neurotransmitters:
The main neurotransmitters of the brain consist of 6. The
first is Acetylcholine; its major function is excitatory at the synapses
involved in muscular movement and memory. The second is Norepinephrine, it is
excitatory and inhibitory at various sites, it is involved in neural circuits
controlling learning, memory, wakefulness, and eating. Serotonin is the 3rd
neurotransmitter, it is also inhibitory and excitatory and is involved in
sleep, mood, and arousal and may be involved in pleasure and pain. Dopamine is
excitatory and involved in voluntary movement, emotional arousal, learning,
memory, and experiencing pleasure and pain. GABA is inhibitory and works in the
motor system- movement. The last neurotransmitter is endorphin; it inhibits
transmission of pain impulses.
Questions regarding the neurotransmitters:
Name and explain briefly all 6 neurotransmitters and their basic
functions.
References:
(n.d.). Retrieved from
http://www.drfrancescott.com/images/neurotransmitter.jpg
Passer, M. W., & Smith, R. E. (5th Edition).
The science of mind and behavior. In McGraw-Hil.
Types of Neurotransmitters
ReplyDeleteCommonly, they are classified into three categories - amino acids, monoamines and peptides. Neurotransmitters like glutamate, aspartate, glycine, serine and gamma aminobutyric acid (GABA) fall into the category of amino acids. On the other hand dopamine neurotransmitter, serotonin, melatonin, epinephrine and norepinephrine are the monoamine neurotransmitters. Calcitonin, glucagon, vasopressin, oxytocin and beta-endorphin are some of the neuroactive peptides. There are about 50 neuroactive peptides till now, with new ones being discovered regularly. Apart from these, acetylcholine, adenosine and nitric oxide are some other noteworthy neurotransmitters
Acetylcholine; its major function is excitatory at the synapses involved in muscular movement and memory. The second is Norepinephrine, it is excitatory and inhibitory at various sites, it is involved in neural circuits controlling learning, memory, wakefulness, and eating. Serotonin is the 3rd neurotransmitter, it is also inhibitory and excitatory and is involved in sleep, mood, and arousal and may be involved in pleasure and pain. Dopamine is excitatory and involved in voluntary movement, emotional arousal, learning, memory, and experiencing pleasure and pain. GABA is inhibitory and works in the motor system- movement. The last neurotransmitter is endorphin; it inhibits transmission of pain impulses.
ReplyDeleteLinda:
ReplyDeleteNeurotransmitters in the Human Body
Acetylcholine
It is the first neurotransmitter to be discovered in the year 1921. This neurotransmitter is responsible for stimulating muscles. It activates the motor neurons that control the skeletal muscles. It is also concerned with regulating the activities in certain areas of the brain, which are associated with attention, arousal, learning and memory. People with Alzheimer's disease are usually found to have a substantially low level of acetylcholine.
Dopamine
Dopamine is the neurotransmitter that controls voluntary movements of the body and is associated with the reward mechanism of the brain. In other words, dopamine regulates the pleasurable emotions, and drugs like cocaine, heroin, nicotine, opium and even alcohol increase the level of this neurotransmitter, for which the user of such drugs feels good. Decreased level of dopamine is associated with Parkinson's disease, while the patients of schizophrenia are usually found to have excess dopamine in the frontal lobes of the brain.
Serotonin
Serotonin is an important inhibitory neurotransmitter, which has been found to have a significant effect on emotion, mood and anxiety. It is also involved in regulating sleep, wakefulness and eating. A significantly low serotonin level is found to be associated with conditions like depression, suicidal thoughts and obsessive compulsive disorder. Many antidepressant drugs work by affecting the level of this neurotransmitter.
Gamma Aminobutyric Acid (GABA)
GABA is an inhibitory neurotransmitter that slows down neuron activity in order to prevent their over excitation, which could lead to anxiety. GABA is a non-essential amino acid, that is produced by the body from glutamic acid. A low level of GABA can have an association with anxiety disorders. Alcohol and drugs like barbiturates can influence GABA receptors.
Glutamate
Glutamate is an excitatory neurotransmitter. It is the most commonly found neurotransmitter in the central nervous system. Glutamate is mainly related with functions like learning and memory. An excess of glutamate is however toxic for the neurons. An excessive glutamate production may be related with the disease, known as amyotrophic lateral sclerosis (ALS) or Lou Gehrig's disease.
Epinephrine and Norepinephrine
Epinephrine is an excitatory neurotransmitter, that is derived from norepinephrine. Epinephrine controls mental focus and attention. Norepinephrine is also an excitatory neurotransmitter and it regulates mood and both physical and mental arousal. Increased secretion of norepinephrine raises the heart rate and blood pressure.
Endorphins
Endorphins are the neurotransmitters that resemble the opioid compounds like opium, morphine and heroin in structure. In fact, their effect on the body is also similar to the effect produced by the opioid compounds. Like opioids, endorphins can reduce pain, stress and promote calmness and serenity. These are the neurotransmitters that enable some animals to hibernate by slowing down metabolism, respiration and heart rate.
-Acetylcholine is one of many neurotransmitters in the autonomic nervous system (ANS) and the only neurotransmitter used in the motor division of the somatic nervous system (sensory neurons use glutamate and various peptides at their synapses). Acetylcholine is also the principal neurotransmitter in all autonomic ganglia.
ReplyDeleteIn cardiac tissue, acetylcholine neurotransmission has an inhibitory effect, which lowers heart rate.
-Norepinephrine affects parts of the brain, such as the amygdala, where attention and responses are controlled.
-Serotonin is primarily found in the gastrointestinal (GI) tract, platelets, and in the central nervous system (CNS) of humans. It is popularly thought to be a contributor to feelings of well-being and happiness.
-Dopamine plays a major role in the brain system that is responsible for reward-driven learning.
-Endorphens are produced by the pituitary gland and the hypothalamus in vertebrates during exercise, excitement, pain, consumption of spicy food, love and orgasm, and they resemble the opiates in their abilities to produce analgesia and a feeling of well-being.
-GABA plays a role in regulating neuronal excitability throughout the nervous system.