June 19, 2020

Here’s a sobering statistic: one in every five American women and one in every 10 American men at the age of 45 are at risk of developing Alzheimer’s disease. Moreover, as the rate of the disease continues to increase and promising therapies tested in rodents fail in human subjects, the need for another option has become apparent.

Now, scientists at the California National Primate Research Center (CNPRC) have developed a monkey model of the earliest phase of Alzheimer’s. By selectively infusing protein fragments linked to the disease into the brain of middle-aged female rhesus monkeys, they have induced the earliest of the stages of Alzheimer’s, known as the synaptic phase, without neuron death. The researchers are focusing on middle-aged females, instead of the older populations previously studied, in hopes of identifying a treatment to stop the disease before irreversible degeneration occurs.

Some neurons, like those in the prefrontal cortex and hippocampus, are critically important for learning and memory and are more susceptible to the effects of Alzheimer’s than others. In a healthy brain, there is a delicate balance necessary for the cellular communication and plasticity necessary for learning—but in Alzheimer’s, this balance is compromised, leading to cognitive decline and possible neuron death.

The scientists believe that by instigating the synaptic damage, they have established a model of Alzheimer’s that isolates the synaptic phase before evidence of permanent damage.

Next, the researchers plan to examine ways of stopping Alzheimer’s progression before it reaches the degenerative phase. Primate models of the disease will greatly boost the capacity to outline an effective treatment plan for humans in the earliest phase of Alzheimer’s, prior to the worst symptoms and irreversible damage that results in dementia.

Interested in what else the NPRCs are doing to understand and improve brain health? Take a look at some related studies here.

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