Brain chemistry neurotransmitters

The piperazines influence brain function through their effects on brain chemistry at different receptors, or specialized locations within nerves allowing them to communicate with each other through chemical messengers called neurotransmitters. By stimulating different groups and locations of nerve cells that contain a specific neurotransmitter called serotonin, piperazine derivatives can have varied, profound effects on mood, learning, perceptions, and movement. 

For years, scientists have known that cocaine interferes with the brain s dopamine system. Dopamine is a neurotransmitter—a chemical that passes nerve impulses from one nerve cell to another, and dopamine is associated with movement, emotional response, and the ability to experience pleasure. Research indicates that serotonin transporters are also inactivated with cocaine use. Serotonin is another neurotransmitter, and adequate levels are associated with well-being. Low levels of serotonin in the brain have been linked to depression. Inactivation of dopamine and serotonin transporters leads to receptor over-stimulation and the high. Continued use of cocaine can result in long-term changes in the brain chemistry as receptors decrease in number. These changes can be persistent and even irreversible, and may be responsible for the feeling of depression that lasts long after withdrawal. 

The active ingredient of St. John s wort is a substance called hyperforin. Like other antidepressants, hyperforin appears to work by helping to restore the proper balance to brain chemistry. In particular, hyperforin helps restore the balance of certain neurotransmitters, or chemical messengers, in the brain. These neurotransmitters include serotonin, norepinephrine, and dopamine. 

Acetylcholinesterase. A pronounced decrease in the level of the neurotransmitter acetylcholine is one of the most pronounced changes in brain chemistry observed in the sufferers of Alzheimer s disease (139). Several drugs that are approved for the treatment of the dementia thought to result from this neurotransmitter deficit act by inhibiting acetylcholinesterase. These include (63) (tacrine, or... 

To more clearly understand the action of antidepressants on brain chemistry, one must have a basic knowledge of neurotransmitters and their actions on brain cells (neurons). 

Greater understanding of the use of these neurochemicals and the newer medications that enhance this response is helping to maximize what we know about the brain, thereby enabling the restoration of normal brain chemistry. When a neurotransmitter s level is too high or too low (by as little as 5 or 10%), it can affect the way other neurotransmitters work (Kotulak, 1997) and can trigger a major chemical chain reaction that affects or contributes to a range of mental health behaviors. 

The remaining step in the process is also a critical one. Somehow the action of the neurotransmitters must cease. If they continue to cross the synapse, or are not removed from the receptors of the postsynaptic cell, they will continue to activate that cell. An overexcited or inhibited nerve cell is not capable of proper function. For example, schizophrenia is a mental disease that is caused by the brain s inability to eliminate excitatory neurotransmitters. The nerve cells continue firing, even when they need not, and the incorrect brain chemistry results in debilitating symptoms such as auditory hallucinations—hearing voices that are not actually there, see also Enzymes Neurotoxins Neurotransmitters Stimulants. 

It is possible to relate brain chemistry and behavior by means of matrix algebra. One can relate specific neurotransmitters and hormones to specific mental functions in vertical axis (columns) and mental processes on the horizontal axis (rows). The entries in the matrix can be used to relate the relative roles of different complex systems of neurotransmitters to different mental functions. Matrices have long been used to solve multiple linear equations, and they have played an important role in the development of computers after World War II. 

Positron emission tomography (PET) is another imaging technique that employs radioactive tracers to image brain activity. PET can detect and map the presence of glucose, neurotransmitters, and a dozen other chemicals critical to brain function. Subtle changes in brain structure or function that correlate to diseases have been used to distinguish brain chemistry changes associated with Alzheimer s disease, schizophrenia, alcoholism, anxiety disorders, and posttraumatic stress disorder. PET can also be used to detect emotional responses and perceptions of emotion. 

Although the hst of drugs of abuse is wide ranging, a central theme is their relationship to brain chemistry and the effect of the drug on neurotransmitters or their receptor sites. Before discussing the mood-altering drugs, it s... 

The use of implantable microelectrodes to study brain chemistry in vivo was pioneered by Adams[14,15] and by Lane and Hubbard [16,17] < It has been shown that neurotransmitters and their metabolites, such as noradrenaline, can be oxidized on graphite electrodes. The desired electrochemical reaction[18] is... 

The chemistry of the brain and central nervous system is affected by a group of substances called neurotransmitters, substances that carry messages across a synapse from one neuron to another Several of these neurotransmitters arise from l tyrosine by structural modification and decarboxylation as outlined m Figure 27 5... 

The medicinal chemistry of Alzheimers is complicated by the fact that the etiology of this disease is still far from clear. Evidence points to an association with decreased levels of acetyl choline in the brain. Many of the drugs that have been introduced to date for treating this disease thus comprise agents intended to raise the deficient levels of that neurotransmitter by inhibiting the loss of existing acetylcholine due to the action of cholinesterase. A compound based on an indene that, perhaps surprisingly, inhibits that enzyme has been proposed for the treatment of Alzheimer s. Aldol condensation of piperidine aldehyde (4-2) with the indanone (4-1) from cyclization of 3,4-dimethoxycinnamic acid leads to the olefin (4-3). Catalytic reduction removes the double bond to afford donepezil (4-4) [3]. 

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