Alzheimer's disease

Definition

Alzheimer's disease is a progressive neurodegenerative disorder characterized by the gradual decline of cognitive function, memory, and behavior. This condition primarily affects older adults and is associated with synaptic degeneration, where communication between neurons deteriorates, leading to the hallmark symptoms of confusion, forgetfulness, and impaired reasoning.

5 Must Know Facts For Your Next Test

1. Alzheimer's disease is the most common cause of dementia, accounting for approximately 60-80% of dementia cases.
2. The disease typically progresses through several stages, starting with mild memory loss and leading to severe cognitive impairment and the inability to carry out daily activities.
3. Genetic factors can play a role in Alzheimer's disease, with certain genes increasing the risk of developing the condition, particularly in early-onset cases.
4. Research suggests that inflammation and oxidative stress in the brain may contribute to the development and progression of Alzheimer's disease.
5. Current treatments focus on managing symptoms rather than curing the disease, with medications available that can temporarily improve or stabilize cognitive function.

Review Questions

• How does synaptic degeneration contribute to the symptoms observed in Alzheimer's disease?
  • Synaptic degeneration in Alzheimer's disease leads to a breakdown in communication between neurons, which is crucial for memory formation and retrieval. As synapses deteriorate, the brain's ability to process information declines, resulting in symptoms such as forgetfulness and confusion. This loss of synaptic function is closely tied to the accumulation of amyloid plaques and neurofibrillary tangles, which further exacerbate neuronal dysfunction.
• Discuss the role of amyloid plaques and neurofibrillary tangles in the pathology of Alzheimer's disease.
  • Amyloid plaques are formed from beta-amyloid peptides that aggregate outside neurons, while neurofibrillary tangles consist of hyperphosphorylated tau protein inside neurons. Both contribute significantly to Alzheimer's pathology by disrupting cellular communication and triggering inflammatory responses in the brain. Their presence is considered a hallmark of the disease and is used as a diagnostic criterion in identifying Alzheimer's disease during post-mortem examinations.
• Evaluate the impact of genetic and environmental factors on the risk and progression of Alzheimer's disease.
  • Both genetic and environmental factors play significant roles in influencing an individual's risk of developing Alzheimer's disease. For instance, variants in genes like APOE ε4 are known to increase susceptibility to late-onset Alzheimer's. Additionally, lifestyle choices such as diet, physical activity, and cognitive engagement can either exacerbate or mitigate risk factors for cognitive decline. Understanding these influences can help develop preventative strategies and therapies aimed at slowing the progression of Alzheimer's in at-risk populations.

Related terms

Amyloid plaques: Abnormal clusters of protein fragments that accumulate between nerve cells in the brains of individuals with Alzheimer's disease, disrupting cell communication.

Neurofibrillary tangles: Twisted fibers made up of tau protein that form inside brain cells of individuals with Alzheimer's disease, contributing to neuronal dysfunction.

Cognitive decline: The gradual loss of cognitive abilities such as memory, reasoning, and problem-solving skills, commonly seen in individuals with Alzheimer's disease.