Japanese researchers have found similarities to Alzheimer’s-afflicted human brains while studying the brains of deceased wildcats.

Researchers analyzed the brains of 14 deceased wild Tsushima leopard cats, according to a study published in PLOS ONE. They found that five of the cats had neurofibrillary tangles (NFT), which is a protein deposit rarely found in non-human species.

They also discovered traces of the peptide Aβ42, which has been shown to play a part in mental deterioration.

Researchers wrote that, “The NFT of the leopard cats were consistent with the pathological characteristics of human AD and were also accompanied by diffuse granular Aβ42 deposits.”

According to the published study, other mammals such as monkeys and dogs rarely develop NFT, though NFT formation has been observed in captive cheetahs.

Research notes
In their written report, researchers noted several aspects of the study that could have affected the results, including:

• The group of 14 cats represents a relatively small sample size for the study.
• The genetic diversity of the cats is limited because they can only be found on Tsushima Island, Japan, and they have been isolated there for 100,000 years. According to researchers, a 2005 study estimated that only 80-110 of the cats existed. This led them to write, “The lack of genetic diversity in this subspecies should be taken into consideration as a potential factor in the peculiar AD pathology seen in these animals.”
• Researchers were unable to observe the animals before their deaths to determine whether they had been exhibiting symptoms of dementia.

Future possibilities
The study may set the stage for future studies on the mechanism of mental deterioration in house cats and other animals, according to a researcher quoted in the Kyodo News.

“If we closely compare changes in the brain among many different animals, we may be able to contribute to a study into the mechanism of the disease,” James Chambers, an assistant professor of veterinary pathology at the University of Tokyo, said.

Read the full study at PLOS ONE