characteristic to Alzheimer’s disease. The physical changes in brain structure, the process towards neurodegeneration, and the numerous hypotheses that are present will also be discussed. These hypotheses include the Amyloid Beta Hypothesis, the Cholinergic hypothesis, the glutamatergic/excitotoxicity hypothesis, the oxidative stress hypothesis, and the chronic inflammation hypothesis will be discussed and analyzed. These hypotheses will not be discussed as a treatment method but rather on the basis
Saunders Co., 1988, p.146. 3.Navarro, H. A., F. J. Seidler, J. P. Eylers, F. E. Baker, S. S. Dobbins, S. E. Lappi, T. A. Slotkin. (1989) Effects of Prenatal Nicotine Exposure on Development of Central and Peripheral Cholinergic Neurotransmitter Systems. Evidence for Cholinergic Trophic Influences in Developing Brain. The Journal of Pharmacology and Experimental Therapeutics, 251(3):894-900. 4. Navarro, H. A., F. J. Seidler, R. D. Schwartz, F. E. Baker, S. S. Dobbins, T. A. Slotkin. (1989) Prenatal
Acid Abnormalities in Dominantly Inherited Olivopontocerebellar Atrophy. Revised manuscript in preparation for resubmission to J. Neurochemistry. Kish, Stephen J. et. al. Cognitive Deficits in Olivopontocerebellar Atrophy: Implications for the Cholinergic Hypothesis of Alzheimer’s Dementia. Annals of Neurology: 24 (2), 200-206, 1988. Rowland, Lewis P. (ed.): Merritt's Textbook of Neurology, eighth edition. Lea and Febiger. Philadelphia, 1959, pp. 630--631. Snell, Richard S: Clinical Neuroanatomy
Through studies performed on sleep-deprived rats, experimental results have shown a decrease in cellular activity in the hippocampus. The hippocampus is responsible for most of the brain’s memory processing. When entering into sleep deprivation, the brain will experience consequences such as a failure for the hippocampus to encode, consolidate, or retrieve signals powering memory processing. As a result, researchers are looking for cellular characteristics that could lead to further details into
Thermoregulation is an essential process involved in the maintenance of homeostasis. It involves the body’s ability to maintain its core temperature within narrow limits, despite varying external temperatures. Thermoregulation helps to protect the body; it enables it to keep functioning at a temperature at which the required chemical reactions in the body can take place. This safeguards the functioning of the body’s vital organs and muscles. A broad range of homeostatic mechanisms are involved in
Introduction Nicotine Nicotine illustrates one of the most popular addictive substances in the world. Since the early colonization of the united states, nicotine has increased in popularity with the first source originating from tobacco. Unfortunately, undesired health effects are present with tobacco use as a result of additives present in the smoke such as cyanide, benzene, formaldehyde, methanol, acetylene, and ammonia. The health effects of tobacco were publicized in the 1960s with large campaigns
The underlying mechanisms appeared to be related to the signal regulation on the cholinergic system and antioxidant enzymes system. The study found that the use of EGb761 can regulate the activity of Acetylcholinesterase (AChE), as well as Choline acetyltransferase (ChAT). ChAT is involved in the synthesis of Acetylcholine (Ach) while AChE
Visual Impairment in Alzheimer's Disease The documentation of a severe form of dementia by Alois Alzheimer in 1907 began a massive investigation of the cause of this disorder. Some of the common symptoms of Alzheimer's Disease consist of memory loss, impaired language ability, impaired judgement, and learning (M. Wong, et al. , 1997). Alzheimer's Disease (AD) is mainly a disease of the cerebral cortex. Alzheimer's is marked structurally by the senile plaques, neurofibrillary tangles, and severe
connectivity, and synaptic function When ethanol is administered to embryos on days one to three of development, the cholinergic neuronal phenotypes were markedly decreased possibly in the sparing of catecholaminergic phenotypes which were increased. This differential sensitivity of these two early neuroblast populations to ethanol may also reflect the difference in their ontogenesis: cholinergic elements are reported to be expressed as early as the primitive streak, whereas catecholaminergic elements appear
these questions, there have been many contributors spent much time to prove that caffeine has been shown to behave as an adenosine antagonist to stimulate motor activity, mood and behavior. This antagonist behavior is the basis for an increase in cholinergic and dopaminergic behavior after caffeine intake. Beside of that, the acute administration of caffeine has been reported by several laboratories to elevate brain level of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA). This increase of
In this lab, we assessed the impact of varying tensions and neurotransmitters on the heart’s rate and contractility. Prior to conducting the experiment, we hypothesized that the more the heart muscle stretches, the greater the force of contraction will be and that if a neurotransmitter can act on a muscarinic and nicotinic receptor without an antagonist present, the agonist will produce a parasympathetic (decrease in heart rate) and sympathetic response (increase in heart rate and contractility)
Pathophysiology of Alzheimer’s Disease The core pathological findings in Alzheimer’s disease include extracellular amyloid plaques, intracellular neurofibrillary tangles and neuronal degeneration. Amyloid plaques are a cardinal feature of AD. They are complex structures which consist of a core of A amyloid protein and surrounded by dystrophic dendritic processes (Serrano-Pozo, Frosch et al., 2011) which are deposited in the cortex. This leads to neuronal damage of the medial
Fear conditioning is a commonly used behavioral paradigm to test an organism’s ability to create associations and learn to avoid aversive stimuli. There are two methodologies: cue and contextual fear conditioning (Kim & Jung, 2006). In cued fear conditioning, a neutral conditioned stimulus (CS) is paired with an aversive unconditioned stimulus (US) which activates a strong unconditioned fear responses (UR). After a continued training period, the neutral CS is now able to activate a conditioned response
Reserpine Reserpine reduces the noradrenaline supplies in peripheral organs. It also reduces the cardiovascular response to sympathomimetic amines. When reserpine is taken the postganglionic sympathetic nerves are not able to transfer impulses through the neuroeffector junctions. Reserpine prevents the acceptance mechanism of amines for the storage of granules for sympathetic tissues. Preventing dopamine uptake into granules, allows reserpine to hinder the formation of noradrenaline. In small dosages
Objective data are observable and measurable. This information is usually obtained through the senses as sight, smell, hearing and touch, during the physical examination of the patient. During Mary was assessed, this is the objective data: symmetrical abdomen, bowel sounds in all quadrants, tender to palpation in the lower quadrants, guarding, skin is warm and moist and her lips and mucous membranes are dry. Subjective data could be described as the vision that the individual has of a situation or
twitching of muscles. The mechanism underlying the toxic effects is that physostigmine targets the acetylcholinesterase and inhibits its activity, which inhibits the hydrolysis of acetylcholine, so increased acetylcholine will be useful to treat cholinergic disorders. Physostigmine, as a tertiary amine and can easily crosses blood-brain barrier. It is a soluble lipid and able to cross-placental barrier mainly by passive diffusion. It is rapidly absorbed from GI tract, subcutaneous tissues and metabolized
Atropine is a non-selective muscarinic cholinergic antagonist and it functions by directly blocking the M3 receptor (Bhattacharjee et al., 2013). This is an example of pharmacological antagonism whereby atropine competitively inhibits Ach, antagonizing the action of Ach at postganglionic muscarinic
Born on the 17 November 1922 Stanley Cohen is a biochemist who worked with Rita Levi-Montalcini on NGF in the 1950s, isolating it and developing an anti-serum. He was born in New York and graduated with a bachelor in double major chemistry and biology from Brooklyn College in 1943. He then graduated from Oberlin College with a Master of Arts in zoology in 1945 and finally earning a PhD from the University of Michigan in the field of biochemistry in 1948. He is described as a quiet, clarinet-playing
prevents the agonist from binding to the receptor and can therefore reduce the agonist response (Dale et al., 2012). The agonist, carbachol and antagonist, atropine are used to show the different responses that is has on a rat ileum. Carbachol is a cholinergic agonist as it binds to muscarinic and nicotinic receptors for acetylcholine and stimulates them, causing a smooth muscle contraction. It is not absorbed well in the gastrointestinal tract and does not cross the blood-brain barrier. Atropine is non-selective
Depression and Antidepressants Specifically the serotonergic hypothesis and the action of Prozac The cause of Clinical depression has long been a mystery to physicians and researchers. Many different theories have been proposed, but no conclusive evidence has been put forth. However, most of what we know about depression stems from the results of certain drugs which have been successful in treating the clinically depressed. These anti--depressants have led to the assumption that depression