Ever wonder if your occasional memory loss means you have Alzheimer's disease (AD)? Or do you wonder if you're seeing personality changes in a loved one that may be a sign of Alzheimer's?
A loss of the sense of smell may be a more reliable and objective marker of the advent of Alzheimer's. According to a Sept. 29, 2011 article on News.healingwell.com, a decrease in the ability to smell odors can be a common early indicator of Alzheimer's disease.
Olfactory sensory neurons are sensory cells located in a small patch inside the nose which are linked to the brain. These neurons are involved in our ability to smell odors.
When this ability is diminished it's called hyposmia. When it disappears completely it's called anosmia. Alzheimer's disease is one of a variety of causes for hyposmia or anosmia.
Amyloid precursor protein (APP) is a mutated form of a protein which may be linked with an increase in olfactory (in the nose) nerve cells dying. Researchers have found APP in the nerve cells of AD patients' noses.
This is seen specifically in some patients who have early onset Alzheimer's, which is genetically passed on and appears before 65 years of age.
In a study, mice with the mutated APP were found to have olfactory nerve cell death that was four times that of normal mice. Less olfactory nerve cells died when APP levels were reduced.
It is hoped that these findings will lead to advances for human beings, though research on animals doesn't necessarily have the same results in human beings.
The research discovered that the dying olfactory nerve cells had no amyloid plaques, which come from APP. This seems to confirm the previous and long-held conclusion that amyloid plaques are involved in the deaths of nerve cells in AD patients' brains.
The research was published in The Journal of Neuroscience on Sept. 28, 2011.
As we get older, the number of our brain cells decreases. Their communication becomes slower. This can be experienced as memory loss. Remembering things can take more time and effort than it used to.
For those with Alzheimer's disease, amyloid plaques disrupt access to the hippocampus.