Scientists may be able to restore Alzheimer's disease memory loss

Jan. 23 (UPI) -- Researchers may have identified a method for restoring memory to people with Alzheimer's disease, according to a new study.

A team of researchers temporarily reversed epigenetic factors in mice that cause memory loss during Alzheimer's progression, they report in research published Tuesday in Brain: A Journal of Neurology.

"We found that in Alzheimer's disease, many subunits of glutamate receptors in the frontal cortex are downregulated, disrupting the excitatory signals, which impairs working memory," Zhen Yan, a SUNY Distinguished Professor in the Department of Physiology at the University of Buffalo, said in a news release.

The epigenetic changes occur in Alzheimer's during its late stages, after a person begins showing the most rapid cognitive decline and stops holding on to recently learned information.

Alzheimer's disease develops from environmental and genetic risk factors that collaborate to create epigenetic changes.

Mice with Alzheimer's disease were injected three times with compounds designed to inhibit the enzyme that controls repressive histone modification.

"Our study not only reveals the correlation between epigenetic changes and AD, we also found we can correct the cognitive dysfunction by targeting the epigenetic enzymes to restore glutamate receptors," Yan said.

Alzheimer's disease raises the level of repressive histone modification, an epigenetic process that leads to the erosion of glutamate receptors. The researchers discovered this glutamate receptor loss in both animal models and post-mortem tissue of people with Alzheimer's.

In this study, the researchers say memory reversal lasted for a week. Now they will set out to create a compound that more effectively penetrates the brain and has a longer-lasting effect.

"We have provided evidence showing that abnormal epigenetic regulation of glutamate receptor expression and function did contribute to cognitive decline in Alzheimer's disease," Yan said. "If many of the dysregulated genes in AD are normalized by targeting specific epigenetic enzymes, it will be possible to restore cognitive function and behavior."