Andy Wells

12 months ago

In a patient with Alzheimer's disease, there are several molecular changes that occur in the brain. The exact mechanisms underlying the development of Alzheimer's disease are still not fully understood, but there are some key molecular hallmarks associated with the condition. These include the accumulation of abnormal protein aggregates, inflammation, and oxidative stress. Let's explore these molecular changes in more detail: Amyloid plaques: One of the characteristic features of Alzheimer's disease is the accumulation of beta-amyloid protein fragments in the brain. These fragments clump together to form insoluble plaques outside the neurons. Beta-amyloid is derived from a larger protein called amyloid precursor protein (APP), which is normally involved in normal brain cell functioning. However, in Alzheimer's disease, beta-amyloid is produced in excessive amounts or is not properly cleared from the brain, leading to the formation of plaques. Neurofibrillary tangles: Inside the neurons of Alzheimer's patients, another abnormal protein called tau forms twisted tangles. Tau is a protein that helps stabilize the internal structure of neurons by supporting microtubules. In Alzheimer's disease, tau becomes abnormal and detaches from microtubules, forming tangled structures inside neurons. These tangles disrupt the transport of essential nutrients and other molecules, ultimately leading to neuronal dysfunction and cell death. Inflammation: Inflammatory processes play a significant role in Alzheimer's disease. Microglia, the immune cells of the brain, become activated in response to the presence of amyloid plaques and release pro-inflammatory molecules. While inflammation is a natural defense mechanism, chronic and excessive inflammation can lead to neuronal damage and contribute to the progression of the disease. Oxidative stress: Alzheimer's patients often exhibit increased levels of oxidative stress in the brain. Oxidative stress occurs when there is an imbalance between the production of reactive oxygen species (ROS) and the ability of the body's antioxidant defense systems to neutralize them. ROS can cause damage to various cellular components, including proteins, lipids, and DNA, leading to impaired cell function and increased neuronal vulnerability.