Cats with dementia share brain changes similar to humans with Alzheimer’s disease, offering a valuable model for studying the condition, according to a study on Tuesday.Scientists at the University of Edinburgh in the UK discovered a build-up of the toxic protein amyloid-beta in the brains of cats with the condition — one of the defining features of Alzheimer’s disease.
Many older cats develop dementia, leading to behavioural changes such as increased vocalisation — or meowing — confusion and disrupted sleep — symptoms similar to those seen in people with Alzheimer’s disease.
“The findings offer a clearer picture of how amyloid beta may lead to age-related brain dysfunction and memory loss in cats,” said Robert I. McGeachan, corresponding author, from the Centre for Discovery Brain Sciences at the varsity.
“Scientists studying Alzheimer’s disease in the past have relied heavily on genetically modified rodent models. Rodents do not naturally develop dementia, and studying cats with dementia has the potential to advance knowledge and help develop treatments for both cats and people,” he added.
The team examined the brains of 25 cats of different ages after they had passed away, including those with signs of dementia.
Powerful microscopy images revealed a build-up of amyloid-beta within the synapses — connections between brain cells — of older cats and cats with dementia.
Synapses allow the flow of messages between brain cells and are vital to healthy brain function. Their loss strongly predicts reduced memory and thinking abilities in humans with Alzheimer’s disease, according to the results published in the European Journal of Neuroscience.
The research team also found evidence that astrocytes and microglia — types of support cells in the brain — engulfed or ‘ate’ the affected synapses. This process, called synaptic pruning, is important during brain development but can contribute to synapse loss in dementia.
The findings will not only help to understand and manage dementia in cats but, given their similarities, could also contribute to the development of future treatments for people with Alzheimer’s disease, t