Alzheimer's Disease

Definition

Alzheimer's disease is a progressive neurodegenerative disorder characterized by the gradual decline in cognitive function, including memory, reasoning, and communication abilities. It is the most common cause of dementia, and it is strongly linked to the misfolding of proteins in the brain, leading to the formation of amyloid plaques and tau tangles that disrupt neural communication and ultimately result in cell death.

5 Must Know Facts For Your Next Test

1. Alzheimer's disease typically manifests with early symptoms such as memory loss and difficulty in performing familiar tasks, gradually progressing to severe cognitive decline.
2. The presence of amyloid plaques and tau tangles is considered a hallmark of Alzheimer's disease, and their accumulation correlates with the severity of symptoms.
3. Genetic factors, such as mutations in the APP, PSEN1, and PSEN2 genes, can significantly increase the risk of developing Alzheimer's disease.
4. Age is the greatest known risk factor for Alzheimer's, with the likelihood of developing the disease doubling every five years after age 65.
5. Current treatments focus on managing symptoms rather than curing the disease, highlighting the importance of ongoing research into potential therapies targeting protein misfolding.

Review Questions

• How do amyloid plaques and tau tangles contribute to the pathophysiology of Alzheimer's disease?
  • Amyloid plaques form when protein fragments accumulate outside neurons, disrupting communication between brain cells. Tau tangles occur when tau proteins become hyperphosphorylated and clump together inside cells. Together, these misfolded proteins lead to inflammation and cell death, resulting in the cognitive decline seen in Alzheimer's patients.
• Discuss the role of genetic factors in the development of Alzheimer's disease and how they relate to protein misfolding.
  • Genetic factors significantly influence the likelihood of developing Alzheimer's disease. Mutations in genes like APP, PSEN1, and PSEN2 have been linked to familial forms of the disease, leading to increased production or aggregation of amyloid-beta protein. This connection underscores how genetic predispositions can enhance protein misfolding processes that drive the pathology of Alzheimer's.
• Evaluate current therapeutic approaches for Alzheimer's disease in light of recent discoveries about protein misfolding mechanisms.
  • Current therapeutic approaches for Alzheimer's focus on alleviating symptoms through cholinesterase inhibitors and NMDA receptor antagonists. However, recent discoveries related to protein misfolding have prompted interest in developing drugs targeting amyloid plaque formation or tau tangles. Evaluating these strategies shows promise in potentially altering disease progression by directly addressing the underlying mechanisms that lead to neurodegeneration.

Related terms

Amyloid Plaques: Abnormal clumps of protein fragments that accumulate between nerve cells in the brains of individuals with Alzheimer's disease, contributing to neurodegeneration.

Tau Tangles: Twisted strands of a protein called tau that form inside brain cells in Alzheimer's disease, disrupting their function and leading to cell death.

Neurodegeneration: The progressive loss of structure or function of neurons, including death of neurons, which is a key feature in Alzheimer's disease and other neurodegenerative disorders.