Abstract
Neurotransmitters play a major role in everyday life and functioning. Everything known about human behaviour suggests it is regulated entirely by the human brain. Brain cells (neurons) communicate with one another (synaptic transmission) and with other cells in the body through small molecules called neurotransmitters (NT). NT are released by neurons and picked up by targeted cells through NT receptors (NTR). Increase or decrease in the production of any of these molecules due to any reason can produce profound effects on behaviour. Knowledge of the pathways involved in NT function has allowed development of drugs that modulate these pathways up or down. Scientists do not yet know exactly how many neurotransmitters exist, but more than 200 chemical messengers have been identified.
TopChapter Outline
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Introduction
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Major neurotransmitters
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Disorders associated with NT systems
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Serotonin
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Glutamate
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Acetylcholine
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Neurotransmitter basis of learning
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Neurotransmitters adverse impacts
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Neurotransmitter Dysfunction in Behavioural Disorder
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Inhibitory Neurotransmitters
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Neurotransmitters influenced by the various drugs
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Conclusion
This chapter highlight the role of relationship of neurotransmitters with behaviour. It includes specifically neurotransmitters classification according to its chemical structure and mechanism of actions, its types etc. Neurotransmitters mechanism of action in various mental disorders is discussed in details to help reader develop the understanding while dealing such conditions in their practice. Students of clinical psychology discipline will have an organised and important understanding and its use in various conditions, its therapeutic role in treating various anxiety, emotional and behavioural disorders.
TopMajor Neurotransmitters
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Amino Acids: glutamate, aspartate, D-serine, γ-amino butyric acid (GABA), glycine
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Monoamines: dopamine (DA), norepinephrine (noradrenaline;NE,NA), epinephrine (adrenaline), histamine, serotonin (SER, 5-HT)
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Peptides: oxytocin, somatostatin, substance P, cocaine and amphetamine regulated transcript, opioid peptides.
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Others: acetylcholine (Ach) etc.
Neurons expressing certain types of neurotransmitters sometimes form distinct systems, where activation of the system affects large volumes of the brain, called volume transmission. Major neurotransmitter systems include the noradrenaline (norepinephrine) system, the dopamine system, the serotonin system, and the cholinergic system, among others. These specific neurotransmitter systems have specific roles in different cognitive, behavioural, emotion and autonomic functions are shown in table1.
TopDisorders Associated With Nt Systems
Diseases and disorders may also affect specific neurotransmitter systems. The following are disorders involved in an increase, decrease, or imbalance of certain neurotransmitters.
Key Terms in this Chapter
GABA: GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter that is very widely distributed in the neurons of the cortex. GABA contributes to motor control, vision, and many other cortical functions. It also regulates anxiety.
ACh: In the autonomic nervous system, acetylcholine (ACh) is the neurotransmitter in the preganglionic sympathetic and parasympathetic neurons. ACh is also the neurotransmitter at the adrenal medulla and serves as the neurotransmitter at all the parasympathetic innervated organs.
Serotonin: Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. It has a popular image as a contributor to feelings of well-being and happiness.
Alzheimer: Alzheimer's disease is a progressive disorder that causes brain cells to waste away (degenerate) and dies. Alzheimer's disease is the most common cause of dementia a continuous decline in thinking, behavioral and social skills that disrupts a person's ability to function independently.
Parkinson: Parkinson's disease is a progressive nervous system disorder that affects movement. Symptoms start gradually, sometimes starting with a barely noticeable tremor in just one hand. Tremors are common, but the disorder also commonly causes stiffness or slowing of movement.
Memory: Memory is the faculty of the brain by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action.
Dopamine: In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons (nerve cells) to send signals to other nerve cells. The brain includes several distinct dopamine pathways, one of which plays a major role in the motivational component of reward-motivated behavior.