The Future of Neuroscience
Alzheimer's disease is a form of dementia (loss of brain function that occurs with certain diseases) that gradually gets worse over time and is the 6th leading cause of death in the United States. It is a neurodegenerative disorder that does not yet have a cure. While deaths from other major diseases have been decreasing over the past 10 years, Alzheimer's death rates have increased by 68%. It is estimated that Alzheimer's disease affects over 5.4 million people in the United States and 35.6 million people worldwide.
Seniors are mostly at risk once progressing past the age of 65. Every 68 seconds, an American develops Alzheimer's and by 2050, it is expected that the development rate will decrease to every 33 seconds and that the number of affected patients will triple. The costs to provide care to those affected by Alzheimer's can reach past $200 billion per year. The Alzheimer's Association is one of the major organizations that funds for the caring of patients with the disease, but prices are currently becoming a major setback.
Alzheimer's Disease
The course of Alzheimer’s Disease is divided into four stages: Pre-dementia, early, moderate, and advanced. During the pre-dementia stage, memory loss is the most noticeable symptom. Additional characteristics of the pre-dementia stage include problems with attentiveness and planning, apathy, and irritability. In the early stage, patients experience difficulty with language, perception, older memories, and implicit memory. During the moderate stage, patients become dependent on others to perform most common activities. They experience speech difficulties such as incorrect word substitutions and the loss of reading and writing skills. Patients in this stage are more prone to irritability, crying, and outbursts of aggression. In the final stage, the advanced stage, the patient is totally dependent on caretakers. Language is greatly reduced and being in this stage can even lead to loss of speech. Patients in the advanced stage of Alzheimer’s also experience deterioration of muscle mass and mobility and become bedridden.
The cause for Alzheimer’s disease is still mostly unknown, with the exception of 5% of cases where it was discovered to have been caused by genetic factors; however, it is believed that Alzheimer’s disease results from a combination of genetic, lifestyle, and environmental factors. Two abnormalities in brain tissue of Alzheimer’s disease patients are considered the hallmarks of the disease: plaques and tangles. Plaques are clumps of a protein called beta-amyloid, which can interfere with cell-to-cell communication. Tangles are formed when threads of the Tau protein in the brain twist, leading to failure of the transport system.
Alzheimer’s disease changes the whole brain; it leads to tissue loss and nerve cell damage/death. Over time, the brain shrinks dramatically. In brains with Alzheimer’s disease, the cortex shrivels up, which damages areas involved in thinking and planning. There is severe shrinkage in the hippocampus, which affects memory. There is shrinkage of the gyri (folds of the brain’s outer layer). In addition to this shrinkage, the ventricles that store cerebrospinal fluid are greatly enlarged.
A recent discovery has shown the effects of using TSPO ligands in 3xTg-AD mice, mice that were engineered to develop Alzheimer's disease. The levels of testosterone and other related hormones that, when lowered, cause Alzheimer’s disease, were purposefully decreased in these mice so that the TSPO ligands could be tested on them. The TSPO ligands’ purpose is to increase these hormones that a patients with Alzheimer's lack. After the research, it was found that symptoms of Alzheimer’s disease were being reduced in the mice tested, especially the aged mice, and even memory was being restored. This technology opens up the possibility of use on humans and help for seniors whose symptoms are severely developed.
