The human mind is like the saying, "You can not teach an old dog new tricks." A new study on mice has shown that the human brain in old age can not learn new things at this stage. The study showed that the micro-brain structures needed for this process New - becomes somewhat rigid at the end of life.

Mice are reliable models in human brain studies, so the results can be trusted as the researchers claim.

Researchers examined the frontal cortex, the responsible area of ​​the brain for different cognitive processes in the brain and play a role in higher learning processes. Researchers have known that brain cells in the frontal cortex of young animals are flexible or plastic. Life experiences, especially learning, can change the circuitry in this region. The brain is deep.

For example, tension causes nerve cells to be cut down and synapses or connections between nerve cells are lost, where communication occurs between them. When the stressful experiment is over, these cells recover or (they are essentially elastic - plastic).

The brain is tense

Scientists have exposed small, medium- and large-sized mice to pressure that stimulates changes in nerve cells in the frontal cortex to see how stress affects the plastic of large brains in the tooth.

After exposing the mice to pressure, scientists looked at close-up images of the structures of nerve cells called thorns. These thorns form synapses that are essential for learning. The professor of neuroscience at Mount Sinai Medical College John Morrison says these thorns change when you learn something new. The area lies learning.

In small mice, brain cells lost many of their thorns, which grew again in a stress-free period. In middle-aged mice, the thorns did not change at all. Another stress-induced effect was a reduction in nerve-like nerves called dendrites. Small and did the same in large mice.

Morrison told us that we can explain that as we age, we lose a lot of new learning experience because of plasticity. He added that learning is the classic example of this kind of plastic, so we think this gives us an effective model to answer the question of why progress In age these cognitive declines and weak learning.

The problem, researchers think, is that when the mouse or human loses these thorns with age, active thorns disappear, which contain many plastics leaving behind hard thorns. These thorns do not have the ability to respond to pressure or learn, Morrison says. .

Cognitive regression

That lack of ability to reconnect cause the cognitive decline of older people.

It may be that such studies are important because they reveal changes in brain cells early in Alzheimer's disease. Before neurons die, at this very early stage, doctors may want to intervene and treat cognitive decline before it is too late.

In fact, there are no animals other than humans that show Alzheimer's disease naturally. In animal models of the disease, scientists must conduct certain experiments on mice and monkeys to generate Alzheimer's.