New medical studies uncover the inner workings of Alzheimer’s disease

WASHINGTON (EFE) .- Scientists from the University of Buffalo (New York, USA) discovered a new approach that could restore memory in patients with Alzheimer’s disease, according to a preclinical study published today in Brain magazine.

“In this report, we not only identified the epigenetic factors that contribute to memory loss, but we also found ways to temporarily reverse them in an animal model,” said lead author Zhen Yan, a researcher at the university.

The team found that by focusing on genetic changes caused by influences other than DNA sequences, called epigenetic, it was possible to reverse memory impairment in mice. The research was carried out with models of mice with familial Alzheimer’s gene mutations, where more than one member of a family suffers from the disease, as well as brain tissues from deceased patients.

The epigenetic changes of Alzheimer’s disease occur mainly when patients cannot retain newly learned information and exhibit an accentuated cognitive decline.

A key reason for cognitive decline is the loss of glutamate receptors, which are critical for learning and short-term memory. “We found that in Alzheimer’s disease, many subunits of glutamate receptors in the frontal cortex are regulated downward, interrupting the excitatory signals, which affects the memory,” Yan said.

The researchers discovered that the loss of glutamate receptors is the result of an epigenetic process known as repressive histone modification, which is elevated in Alzheimer’s patients. According to the authors, this “abnormal” modification of histone linked to Alzheimer’s is what represses gene expression, decreasing glutamate receptors, which leads to loss of synaptic function and memory deficits.

Once this dysfunction was detected, they injected compounds designed to inhibit the enzyme that controls the repressive histone modification three times in the alzheimer’s affected mice. “When we gave the animals of Alzheimer’s disease this inhibitor of enzymes, we saw improved cognitive function through the evaluation of recognition memory, spatial memory and working memory,” said the researcher.

“We were quite surprised to see such a drastic cognitive improvement,” Yan added.

At the same time, the authors confirmed the recovery of the expression and function of the glutamate receptor in the frontal cortex. These improvements lasted a week, so future studies will focus on developing compounds that penetrate the brain more effectively and, therefore, are much more durable.

TYT Newsroom with information from