Neurofibrillary tangles

Definition

Neurofibrillary tangles are abnormal aggregations of hyperphosphorylated tau protein that accumulate inside neurons, primarily associated with neurodegenerative diseases such as Alzheimer's disease. These tangles disrupt cellular function, contributing to the degeneration of neurons and cognitive decline seen in affected individuals. Their presence is a hallmark of various nervous system disorders and is indicative of the severity of the disease process.

5 Must Know Facts For Your Next Test

1. Neurofibrillary tangles are formed when tau protein becomes hyperphosphorylated, leading to its misfolding and aggregation inside neurons.
2. The presence and density of neurofibrillary tangles in the brain correlate strongly with the severity of cognitive impairment in Alzheimer's disease.
3. Neurofibrillary tangles can spread throughout the brain in a prion-like manner, affecting other neurons and exacerbating neurodegeneration.
4. While primarily associated with Alzheimer's disease, neurofibrillary tangles can also be found in other tauopathies, such as frontotemporal dementia and chronic traumatic encephalopathy.
5. Current research is focused on understanding the mechanisms behind tau phosphorylation and developing potential therapies aimed at reducing or preventing the formation of neurofibrillary tangles.

Review Questions

• How do neurofibrillary tangles contribute to cognitive decline in patients with Alzheimer's disease?
  • Neurofibrillary tangles disrupt normal neuronal function by interfering with essential cellular processes, including axonal transport and cell signaling. As these tangles accumulate, they lead to neuronal death, which directly contributes to cognitive decline. The extent of cognitive impairment in Alzheimer's disease correlates with the number and distribution of these tangles in the brain.
• Discuss the relationship between neurofibrillary tangles and other pathological features observed in Alzheimer's disease.
  • Neurofibrillary tangles are often found alongside amyloid plaques in the brains of individuals with Alzheimer's disease. While amyloid plaques form extracellularly from beta-amyloid peptides, neurofibrillary tangles develop intracellularly from hyperphosphorylated tau protein. The interaction between these two pathological features may exacerbate neuronal dysfunction and death, contributing to the overall progression of the disease.
• Evaluate the potential implications of targeting tau protein in therapies aimed at treating neurodegenerative diseases characterized by neurofibrillary tangles.
  • Targeting tau protein presents an opportunity to develop novel therapies for neurodegenerative diseases like Alzheimer's that are characterized by neurofibrillary tangles. By preventing tau hyperphosphorylation or promoting its clearance from neurons, researchers hope to halt or slow down disease progression. This approach could have significant implications for improving cognitive function and quality of life for affected individuals, potentially altering the course of these devastating diseases.

Related terms

Tau protein: A protein that stabilizes microtubules in neurons, which, when hyperphosphorylated, leads to the formation of neurofibrillary tangles.

Alzheimer's disease:

A progressive neurodegenerative disorder characterized by memory loss, cognitive decline, and the presence of amyloid plaques and neurofibrillary tangles in the brain.

Amyloid plaques: Extracellular deposits of beta-amyloid peptides that accumulate in the brains of individuals with Alzheimer's disease, often found alongside neurofibrillary tangles.