Norepinephrine is usually quickly removed from the synapse and pumped back into the cell that released it in order to turn off and reset the system. By blocking the removal of norepinephrine, tricyclics appear to prolong or intensify norepinephrine's message to the post-synaptic cells.
However, the fundamental biochemical effect of antidepressants on the brain that is responsible for their benefit remains a mystery. It is thought that the change in neuroamine signaling at the synapse caused by anti-depressants "may set off a cascade of events involving second messenger systems that eventually results in the improvement of the symptoms of depression" (Enna, 1991, 187). Unfortunately, how these medications truly operate remains largely unknown.
Another group of anti-depressants is called selective serotonin re-uptake inhibitors, first introduced in 1988. Unlike the tricyclics, these new anti-depressants have little direct effect on norepinephrine in the brain; instead, they block the re-uptake of serotonin which gives this class its name, sometimes referred to as SSRIs. As with the tricyclics, the effect of serotonin in the synapse seems to occur at the receptors, and there is some evidence that "serotonin is actually the more important neurotransmitter in the treatment of depression" (Kendler, 1992, 720). The development of these new agents which help with depression but which seem to work differently from the tricyclics has provided more clues to the underlying biology of many mood disorders.
Since the early 1990's, an entirely new series of anti-depressants emerged that are neither tricyclics nor selective serotonin re-uptake inhibitors. Most of these agents do not share common features, yet they do generally effect norepinephrine, serotonin and other neurotransmitters. One of them is iproniazid, developed initially for the treatment of tuberculosis. This drug causes inactivation of an enzyme in the body that metabolizes amine compounds in the nervous system. This enzyme called monoamine oxidase "gobbles up molecules of norepinephrine, serotonin and other neurotransmitters" (Enna, 1991, 234). The inactivating effect of iproniazid on the enzyme gives this class its name -- monoamine oxidase inhibitors, or MAOIs.
Another anti-depressant is known as valproate which is generally used for bi-polar depression; however,...
123). In this study, Martinez-Contreras and her associates report the results of recent research that has provided additional evidence concerning the function of these proteins in precursor-messenger RNA (pre-mRNA) splicing (2007). The splicing repression can function in two discrete ways in heterogeneous nuclear RNP proteins; the first way is by antagonizing the recognition of splice sites directly and the second way is through interference with the binding of proteins that
Biochemistry Similarity of Glycolysis in Prokaryotes and Eukaryotes Glycolysis is reported as being a pathway that is practically universal for energy extraction that carbohydrates hold available and this is true for eukaryotes, prokaryotes as well as aerobes and anaerobes. (Essential Biochemistry, 2014, paraphrased) Only eukaryotes have mitochondria. Some prokaryotes are reported to be photosynthetic and to use "an electron transport chain to make ATP." (Essential Biochemistry, 2014, p. 1) It is believed that
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The next database used for the search is Medline. I began with the same search terms, celiac disease biochemistry, however it did not return any articles. Next, the search was expanded my search by simply searching celiac disease. This returned 544 articles. The first article is titled Celiac Disease and is from the National Library of Medicine. This article is clearly not useful. Next the search was expanded to celiac
student with a Bachelor of Science degree in Communications, minors in both Psychology and Sociology, and a desire to attend law school, my request to enter a Biochemistry program may be unusual. After all, people who focus on the hard sciences usually do so because of plans to work in a particular industry or to pursue additional field-specific education via Masters or PhD programs. Because I have no intention
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