Glutamate – An Excitatory Neurotransmitter
Neurotransmitters are essential for transferring information between neurons and are released from a presynaptic terminal into a synaptic cleft. When the neurotransmitters bind to the postsynaptic receptors (specialized protein molecules that capture and react to molecules of the neurotransmitter), it induces an ionic flux which depolarizes the neuron. Neurotransmitter binding may also cause metabolic changes such as the activation of secondary messenger systems. Efficient neurotransmitters must satisfy two requirements: the level of neurotransmitter in the synaptic cleft must be kept low in order to maximize the signal-to-noise ratio upon binding of fresh transmitter to its receptor; and the second requirement is the rapid replacement of a transmitter that is released from a presynaptic terminal (Glutamate and Glutamine in the Brain, 2000). I am choosing glutamate as my neurotransmitter of choice, so in order for glutamate to be an efficient neurotransmitter, a low external signal-to-noise ratio must be preset in order to prevent excitotoxicity which can damage and even kill nearby neurons. Glutamate must also need to be removed from the synapse or it must have to be resynthesized within the
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When the brain is operating normally, there is a transient synaptic release of glutamate that causes calcium to flow into the cell. This helps with learning and memory. However, since there is a constant flow of calcium ions into the brain, the signal can no longer be detected which leads to the occurrence of dementia symptoms. Over the course of the disease, there is a constant release of glutamate which permanently increases the flow of calcium into the cell, which eventually leads to neurological
In the book, Crispin: The Cross of Lead, the protagonist Crispin faces many conflicts throughout the book in which he must conquer in order to find who he really is. These conflicts change Crispin as a character over the course of the book, as he overcomes them to find out his true self. One conflict for Crispin is person vs society where he becomes known as a wolf’s head and does not have any friends, or family. This is until he meets Bear who helps Crispin overcome this conflict. For example, John Aycliffe tries to find Crispin, but helps him get away. As the story develops Crispin saves Bear from John Aycliffe, showing their friendship.
When a chemical signal is transmitted, the presynaptic neuron releases a neurotransmitter into the synapse. The signal is then sent to the postsynaptic neuron. Once the postsynaptic neuron has received the signal, additional neurotransmitter left in the synapse will be reabsorbed by the presynaptic
The presynaptic terminal stores high concentrations of neurotransmitter molecules in vesicles, which are tiny nearly spherical packets. These molecules are then released by depolarization. Depolarization opens voltage-dependent calcium gates in the presynaptic terminal. After calcium enters the terminal, it causes exocytosis, which is the burst of release of neurotransmitters from the presynaptic neuron. After its release from the presynaptic cell, the neurotransmitter diffuses across the synaptic cleft to the postsynaptic membrane, where it attaches to the receptor.
Creutzfeldt-Jakob is a fatal, progrossive and incurable neurologic disorder which affects the brain in a destructive way. Globally, it attacks one person in every one million people. Specifically, at United State there are more than 300 cases per year. However, it is extremely complicated to diagnose, so the number of cases might get higher in the future. CJD (Creutzfeldt-Jakob disease) symptoms usually occur in later life for women and men whose ages are between 60 and 70. This essay displays a definition of Creutzfeldt-Jakob disease based on its identity, causes, symptoms, risk factors and treatment.
Amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig's disease, is a disease of the nerve cells in the brain and spinal cord that control voluntary muscle movement. Jean-Marie Charcot was the first to recognize ALS as a distinct neurological disease with its own unique pathology. In ALS, nerve cells degenerate and deteriorate, and are unable to transmit messages to muscles. In around 90% of the cases of ALS, the cause remains unknown. Studies have concentrated on the responsibility of glutamate in motor neuron degeneration. Glutamate is one of several neurotransmitters in the brain. While there is no known cure for ALS, strides in medicine have allowed for the development of a wide variety of medications to treat the various symptoms of ALS, as well as dietary, physical therapy, and breathing techniques, all of which can lessen symptoms and increase life expectancy.
Nerve cell death and tissue throughout the brain is the most significant affect over time. Naturally by age twenty-five the brain starts to decrease in size. With Alzheimer’s, the amount decrease is extremely significant. The cortex begins to shrivel up which is the part of the brain required for planning, remembering, and thinking. The most noticeable shrinkage occurs in the hippocampus. The hippocampus is responsible for the formation of new memories, it is also located inside the cortex. Upon further inspection under microscope, tissue samples are observed and synapses and nerve cell count is severely decreased. Tangles, are also found which our twisted strands of another protein due to nerve cells dying and bunching together. Plaques and tangles are prime suspects in the death and tissue loss in the Alzheimer’s brain. Beta-amyloid is a chemical and is sticky which causes it to gradually build up into plaques. This chemical derives from a larger protein found in the nerve cells with fatty membranes. These tangles destroy a vital cell transport system made of proteins.
Ulta has a unique and revamped program that not only attracts consumers back, but offers birthday markdowns and other discounts. This reward system is called Ultamate Reward. Loyalty programs are made to build (an connection?) with customers, so they can feel comfortable coming back. The loyalty programs also allow consumers to earn points for every dollar they spend and earn double the points during consumers’ birthday month. These points can be redeemed with discount price for future transactions. Unlike Ulta, Sephora only allows consumers to redeem their points with product samples instead of discount prices. Ulta’s goal in this program is to “provide a level of transparency not found in many retail loyalty programs” (Jafari). Ulta sends
Alzheimer’s disease is a progressive disease that destroys memory and other important mental functions. Alzheimer’s disease affects central nervous, neuromuscular, and digestive system. In the digestive system, swallowing difficulties are common for people who suffer from Alzheimer’s disease. In the neuromuscular system, the ability to walk and maintain their posture in a chair is common for people with Alzheimer’s. In Alzheimer’s disease, the connections between brain cells and the brain cells themselves deteriorate and die, which causes a steady decline in memory and mental function. It is the most common cause for dementia, which is a brain disorder that results in the loss of intellectual and social skills. (Staff, 2013) It is severe enough to interfere with every day activities. It is important to seek support through counseling and maintain medical assistance through medication or any other form of aid. Alzheimer’s disease is a condition that should be considered a priority in order to be able to maintain a decent lifestyle.
Dementia can occur in relation to many different illnesses. Some of the most common of which are Huntington’s Disease,
Immunodeficiency diseases are any diseases that cause an absence or inadequate immune response. They usually effect the immune cells, T-cells, B-cells, complement cells, or phagocytes. Immunodeficiency disease can cause many complications in the body. The compromise of the immune system can eventually lead to death if it is not treated promptly and correctly. A rare immunodeficiency disease that can lead to death is Wiskott-Aldrich Syndrome.
Rationale: As explained in the background, CGRP activates adenylate cyclase increasing the cytosolic cAMP. My preliminary data show that cAMP potentiates increased Ca2+ influx into the SGNs synonymous with the synaptopathy. The preliminary experiments that showed CGRP might potentiate synptopathy was done by Qiong Wang, a former postdoc in our lab. Due to the lack of appropriate antibodies she had to count the axonal fibers instead of synapses. This method is obsolete now, as SGNs are found usually in bundles before they make synapses, which makes this method unreliable. I intend to redo the treatment with CGRP and cAMP in the organotypic culture
This disease causes memory loss, difficulty in thinking processes, mood swings, depression, hallucinations, personality changes, and the inability to create new memories. Alzheimer’s disease is most common in people who are at the age of sixty years or older, but it can start as early as the age of nineteen. It can be categorized as a type of dementia. “Scientists believe Alzheimer’s disease prevents parts of a cell’s factory from running well” (Alzheimer’s Disease: The basics). Scientist believe that one cause of Alzheimer’s could be caused by plaques and tangles. Plaques are the build up of a protein called beta-amyloid in the nerve cells. Tangles are twisted fibers of the tau protein that build up inside of a cell. The exact cause of Alzheimer’s has not yet been determined, but scientists have reason to believe that it is because these plaques and tangles are blocking the communication of cells in the nervous system. Another probable cause is a mutation on the chromosomal genes 21, 14, and 1. This is why it is believed to be a genetically inherited
It is the most common cause of premature senility. When a person has Alzheimer’s it slowly destroys the person's memory, along with different skills such as thinking skills. When you have Alzheimer’s your brain tissue will start to shrink and keep shrinking while creating holes in your brain. Out of everything your brain is mostly affected which makes it harder for the brain to communicate with the rest of your body. This makes the healthy neurons in the brain lose connections with other healthy neurons and die. As more of these neurons die, it affects more of the brain which causes the brain to shrink. While this is happening abnormal deposits of proteins from the amyloid plaques and tau tangles are being deposited in the brain.
Dementia is an organic brain syndrome which results in global cognitive impairments. Dementia can occur as a result of a variety of neurological diseases. Some of the more well known dementing diseases include Alzheimer's disease (AD), multi-infarct dementia (MID), and Huntington's disease (HD). Throughout this essay the emphasis will be placed on AD (also known as dementia of the Alzheimer's type, and primary degenerative dementia), because statistically it is the most significant dementing disease occurring in over 50% of demented patients (see epidemiology).
Alzheimer's is a very complex disease. So complex that very little has been discovered about it but that is rapidly changing. Findings from epidemiology, genetics, molecular and cell biology are fitting together in the Alzheimer's puzzle, helping researchers to identify some of the mechanisms that underlie it. Alzheimer's starts because the normal processing of certain proteins goes terribly wrong. This causes brain cells and the spaces between them to be cluttered with pieces of toxic protein. Closer investigating with microscopes has revealed a loss of nerve cells in certain regions of the brain. Some of these dying nerve cells communicate using the neurotransmitter acetylcholine, these compounds eventually break down by an enzyme called acetylcholinesterase. Also responsible for Alzheimer's are clusters of proteins in the brain which come in two forms: those found inside the nerve cells and those found in between the cells.