Last week, World Alzheimer’s Day recalled research that could change the current direction of the disease. The study, awarded in 2014 with the Nobel Prize in Medicine, shows a positioning in the human brain similar to a ‘GPS’ of the nervous organ.
Three researchers are responsible for the discovery: John O’Keefe and the couple May-Britt Moser and Edvard Moser. The mapping brings a sequence of coordinated cells that react to the nervous system, known as grid cells. The function guides where we are and what our relationship is with a place, space or memory, dividing it between pertinent and temporary memories.
The second part of the survey now is to identify the relationship between mapping and Alzheimer’s. “The area of the brain that contains all of these specialized cells and records the passage of time is often the first region to be damaged in Alzheimer’s,” Edvard Moser told BBC News Mundo.
Alzheimer’s is a disease that presents itself as dementia, caused by the loss of cognitive functions such as memory and language. In Brazil, the Brazilian Alzheimer’s Association (Abraz) estimates about 1.2 million cases in the country – most of them undiagnosed.
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The research that won the biggest prize of Medicine to the trio
John O’Keefe made it possible to begin studies of the neural network of the hippocampus memory – the main structure in our brain responsible for memory. In 1971, a survey by the physician identified that the region has “local cells” that fire when a rodent is in a particular location.
“But it was not clear whether these signs of place originated in the hippocampus itself or came from outside,” explain the experts on the website. Kavli Institute for Neuroscience Systems at the Norwegian University of Science and Technology, founded by the Mosers after their studies began.
During the process, they soon noticed signals emitted elsewhere in the brain, the entorhinal cortex. The region has important direct connections to one of the areas of the hippocampus. The road to the main discovery – in 2002 – was a long one.
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Soon the trio realized that many entorhinal cells increased their frequency emitted in the brain each time a rat went to a certain location. The locations formed a regular pattern, like a hexagonal grid, and maintained a firing relationship from one environment to another., forming a kind of brain mapping.
The grid pattern between the two areas, published in 2005, led to other research that helped to answer how do we know where we are and why do we walk where we are going?. “Because the standard is so reliable and regular, it can put us on the right path to understand the fundamental calculations of the cortex,” explain the Nobel Prize winners in Medicine.
However, nothing of the trio’s research would be possible without a special patient: known as H.M., his initials were used to preserve the identity of a revolutionary man to the field of neurological medicine.
The HM patient
As a child, HM suffered from seizures after a bicycle accident. Only at the age of 27 did he accept to be part of a procedure in which the hippocampi of his brain would be removed. After the procedure, the man stopped having seizures and his intelligence quotient increased, according to information from the BBC.
But soon the doctors realized that he couldn’t remember recent activities – like what you had for breakfast or if you went to the bathroom. They were fleeting, unlike old memories. HM could remember his childhood and specific details of his life before surgery, but all memories after surgery would be instantaneous.
Soon the case intrigued specialists, in which they worked for almost five decades with the patient later revealed as Henry Molaison. He was the only one to go through the procedure, considered a milestone. Your brain continues to be researched for more precise information about the organ’s functioning and its pathologies, such as Alzheimer’s.