The Black Death is still affecting the human immune system, and recent findings suggest that it may still be at work in the brains of those suffering with Alzheimer’s disease. Scientists have long suspected that Alzheimer’s disease may be related to the overproduction of the inflammatory cytokine interleukin-1b (IL-1b) from microglial cells in the brain. Now, researchers have found that microglia are also chronically inflamed in individuals with Alzheimer’s disease, and propose that microglia-derived IL-1b may play a role in the disease’s pathology.
ADHD. Although many individuals suffering with ADHD have difficulty controlling their ADHD symptoms, it is still not clear whether genetics plays a role in ADHD. A new study reveals that ADHD patients who carry the genetic risk gene for ADHD also have a higher risk of developing Alzheimer’s disease. When the researchers analyzed blood from ADHD patients with ADHD symptoms and also from ADHD patients without ADHD symptoms, they found that some genetic markers for ADHD were associated with lower levels of IL-1b, a protein in the brain that is associated with Alzheimer’s disease. The findings, led by researchers from the University of California–San Diego, appear in the current issue of the American Journal of Pathology.
In another recent study, scientists found that mice with Alzheimer’s disease-like symptoms show abnormal levels of IL-1b, the same cytokine that is also thought to be implicated in ADHD. These findings indicate that IL-1b likely plays a role in the onset of Alzheimer’s disease, as well as in ADHD-related behaviors such as hyperactivity.
A previous study had found that, in young mice, IL-1ra, a protein that prevents inflammation, blocked the development of memory loss caused by the amyloid β-peptide (Aβ) found in Alzheimer’s disease but not in controls.
The researchers also found that in Alzheimer’s disease-like mice that were treated with the anti-inflammatory drug minocycline, the memory loss was restored.
The researchers caution that the study is only a small one, so more work will be needed to clarify the significance of the findings.
The study also reveals a previously unrecognized link between Alzheimer’s and ADHD. ADHD is a long-suspected contributing factor in the onset of Alzheimer’s disease, and is often seen together with the disease itself. As of yet, no definite study has shown a direct causal relationship between ADHD and Alzheimer’s, but this
