Neurodegeneration

Definition

Neurodegeneration is the progressive loss of structure or function of neurons, including the death of neurons. It is a key feature of various neurological disorders, such as Alzheimer's disease, Parkinson's disease, and prion diseases, and can be caused by a variety of factors, including genetic mutations, environmental toxins, and infectious agents.

5 Must Know Facts For Your Next Test

1. Neurodegeneration can be caused by the accumulation of misfolded proteins, such as amyloid-beta in Alzheimer's disease or alpha-synuclein in Parkinson's disease, which can disrupt normal neuronal function and lead to cell death.
2. Viral infections, such as those caused by prions or certain viruses, can also trigger neurodegeneration by directly damaging or inducing the death of neurons.
3. Genetic mutations can lead to the production of defective proteins that are prone to misfolding, aggregation, and disruption of normal cellular processes, ultimately resulting in neurodegeneration.
4. Environmental factors, such as exposure to certain toxins or traumatic brain injuries, can also contribute to the development of neurodegenerative diseases by inducing oxidative stress, inflammation, and neuronal damage.
5. Neurodegeneration is a common feature of prion diseases, such as Creutzfeldt-Jakob disease (CJD) and bovine spongiform encephalopathy (BSE), which are caused by the conversion of normal prion proteins into an abnormal, infectious form.

Review Questions

• Explain how the accumulation of misfolded proteins can contribute to neurodegeneration.
  • The accumulation of misfolded proteins, such as amyloid-beta in Alzheimer's disease or alpha-synuclein in Parkinson's disease, can disrupt normal neuronal function and lead to cell death. These misfolded proteins can aggregate and form toxic oligomers or insoluble fibrils that interfere with cellular processes, including synaptic function, axonal transport, and mitochondrial activity. This can ultimately result in neuronal dysfunction and degeneration, contributing to the progressive symptoms observed in neurodegenerative disorders.
• Describe the role of viral infections in triggering neurodegeneration.
  • Certain viral infections can directly damage or induce the death of neurons, leading to neurodegeneration. For example, prion diseases, such as Creutzfeldt-Jakob disease (CJD) and bovine spongiform encephalopathy (BSE), are caused by the conversion of normal prion proteins into an abnormal, infectious form that can propagate and cause neuronal damage. Additionally, some viruses, such as those associated with HIV/AIDS, can indirectly contribute to neurodegeneration by inducing inflammation, oxidative stress, and disrupting normal neuronal function.
• Evaluate the impact of genetic mutations and environmental factors on the development of neurodegenerative diseases.
  • Genetic mutations can lead to the production of defective proteins that are prone to misfolding, aggregation, and disruption of normal cellular processes, ultimately resulting in neurodegeneration. This is observed in various inherited neurodegenerative disorders, such as Huntington's disease and some forms of Alzheimer's disease. Additionally, environmental factors, such as exposure to certain toxins or traumatic brain injuries, can also contribute to the development of neurodegenerative diseases by inducing oxidative stress, inflammation, and neuronal damage. The interplay between genetic predisposition and environmental exposures can significantly influence the onset and progression of neurodegenerative diseases, highlighting the complex etiology of these disorders.

Related terms

Apoptosis:

A form of programmed cell death that occurs in multicellular organisms, in which a cell actively participates in its own destruction as part of a normal and controlled biological process.

Proteinopathy: A group of neurodegenerative disorders characterized by the abnormal accumulation of misfolded proteins in the brain, leading to neuronal dysfunction and death.

Prion Diseases:

A group of rare, fatal neurodegenerative disorders caused by the conversion of normal prion proteins into an abnormal, infectious form that can propagate and cause neuronal damage.