A cluster of brain cells that are among the first to degenerate in Alzheimer’s disease were found in a study to be impaired in a rare form of amnesia that blocks autobiographical memories, and may be a future target to treat the dementia.
Fourteen of 16 people with acute transient global amnesia, a rare type of temporary memory loss, had pronounced lesions on the cells known as CA1 neurons, according to a report in the Proceedings of the National Academy of Sciences. That suggests the neurons must work properly to let memories be gathered and catalogued for later use, said Gunther Deuschl, a neurologist at University-Hospital Schleswig-Holstein in Kiel, Germany.
Autobiographical memory allows people to recall events in historical context, helping create self-identity and awareness, the researchers wrote. The neurons studied are located in the brain’s hippocampus, long known as one of the first regions to suffer damage in Alzheimer’s.
“This is a key player in the deficits of Alzheimer’s disease,” said Deuschl, who was a study author, in a telephone interview. “This type of amnesia mimics the cognitive problems Alzheimer’s patients have very early on in the disease, but on a different time scale.”
The underlying cause of acute transient global amnesia is unknown. Patients with the disorder display an inability to form new memories or recall the recent past, though they are still able to recognize and name familiar objects. The spells last no more than 24 hours before memory gradually returns, according to the Mayo Clinic Web site.
To gain the finding, the researchers scanned patients in an MRI machine during a period of autobiographical memory loss, using a questionnaire that asked them to recall events that occurred during different times in their lives.
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