Inside Alzheimer’s disease

Summary

The script delves into Alzheimer's disease, exploring its discovery by Alois Alzheimer over a century ago and the ongoing research into its causes and potential cures. It explains how amyloid beta plaques and tau tangles disrupt neuron function, leading to memory loss and cognitive decline. The script also highlights the role of immune cells like microglia in the disease's progression, as well as the spreading nature of tau pathology across the brain. Despite significant advances in understanding the disease, no cure exists yet, and the need for continued research remains crucial.

Takeaways

• 😀 Over a century ago, Dr. Alois Alzheimer discovered brain abnormalities in a dementia patient, leading to the study of Alzheimer's disease.
• 😀 Alzheimer's disease is linked to the buildup of amyloid beta plaques in the brain, which are caused by the cleavage of Amyloid Precursor Protein by beta and gamma secretase.
• 😀 Amyloid beta (Abeta) misfolds and aggregates into oligomers, which can impair brain function, especially in memory formation and retrieval.
• 😀 Microglia, the brain's immune cells, are activated by amyloid beta and cause inflammation, damaging neurons and disrupting synaptic connections.
• 😀 As neurons die, abnormal brain activity patterns emerge, which affect the brain's ability to process and store information properly.
• 😀 Neurodegeneration in Alzheimer's disease is largely driven by amyloid beta, but tau proteins also play a significant role in neuronal damage.
• 😀 Tau proteins, in healthy neurons, help stabilize microtubules, but in Alzheimer's, tau becomes misfolded and detaches from microtubules, forming tangles that contribute to neuron death.
• 😀 Misfolded tau proteins can spread between neurons, causing healthy tau proteins to misfold as well, furthering the disease's spread.
• 😀 The pattern of tau protein spread in the brain corresponds to the stages of Alzheimer's disease, from early to late stages, and reflects the vulnerability of certain neurons.
• 😀 Despite progress in understanding Alzheimer's disease, there is still no cure, and research into targeting amyloid beta and tau is ongoing with uncertain outcomes.

Q & A

What did Dr. Alois Alzheimer discover over a century ago?

Dr. Alois Alzheimer observed anomalies in brain sections of a patient with dementia, which led to the identification of what is now known as Alzheimer's disease.

What are amyloid plaques and why are they important in Alzheimer's disease?

Amyloid plaques are insoluble deposits of a peptide called amyloid beta (Abeta). They are a key feature of Alzheimer's disease and form when the Amyloid Precursor Protein is cleaved by beta and gamma secretase enzymes.

How does amyloid beta contribute to Alzheimer's disease?

Amyloid beta misfolds and becomes sticky, leading to the formation of soluble oligomers that aggregate into large insoluble fibrils, which deposit in the brain as plaques. These plaques disrupt communication at synapses, which affects memory formation and retrieval.

What role do microglia play in Alzheimer's disease?

Microglia are immune cells that clear out waste and prune synapses. In Alzheimer's, they are activated by amyloid beta, releasing inflammatory cytokines that can damage neurons and contribute to the removal of synapses.

What is the significance of tau in Alzheimer's disease?

Tau is a protein that stabilizes microtubules in neurons. In Alzheimer's, tau becomes modified, dissociates from microtubules, adopts an abnormal shape, and forms tangles. This disrupts neuron function and contributes to neurodegeneration.

How does tau contribute to the spread of Alzheimer's disease?

Misfolded tau proteins can spread across synapses into healthy neurons, causing the healthy tau to misfold as well. This leads to the propagation of tau-related pathology across different brain regions.

What happens to neurons in Alzheimer's disease?

In Alzheimer's disease, neurons suffer damage and death due to the effects of amyloid beta and tau. This leads to the malfunction of synapses and a breakdown in the brain's ability to process and store information.

How does the spread of tau correlate with the stages of Alzheimer's disease?

The spread of tau through different brain regions mirrors the progression of Alzheimer's symptoms, from early to late stages, and reflects the vulnerability of certain neurons to damage.

Why is it difficult to develop a cure for Alzheimer's disease?

Despite advances in understanding Alzheimer's disease, there is no cure. Drugs targeting amyloid beta or tau are under development, but it remains unclear whether they will be effective in treating the disease.

What is the key to making progress in treating Alzheimer's disease?

Continued support for basic and clinical research is essential to improving our ability to diagnose and treat Alzheimer's disease in the future.