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In recent decades, technological and health advances have improved the quality of people’s life by increasing longevity. Despite these improvements in life expectancy, Alzheimer's disease and related neurodegenerative conditions have increased in older people.

Consequently, there has been a growing interest in the study of certain habits such as physical activity or the consumption of specific diets, and their beneficial effects on health. It has been known for more than a century that the calorie-restricted diet, which consists of a reduction in calorie intake without malnutrition and with the intake of the necessary micronutrients, is able to prolong the lives of both animals and humans. The mechanisms by which caloric restriction induces longevity are well known. It is recognized that in addition to improving health it also slows down the onset of diseases associated with aging. However, the effects of the calorie-restricted diet on the brain and its ability to attenuate the loss of cognitive functions is a topic of debate that has aroused much interest in the field of Psychology and Neuroscience.

In the laboratory of Psychobiology of the Faculty of Psychology and the Institute of Neurosciences of the UAB, research has been carried out with rats raised in different dietary conditions. While half of the animals had free access to food, the other half underwent a diet with a 30% reduction in usual intake from four months of age. When they reached the age of twenty-four months, the aged animals and a group of young rats, used to assess the effects of age on cognitive decline, were trained in a test that consisted in finding a non-visible platform submerged in a circular pool from signals located outside the aquatic labyrinth. After training, all animals were subjected to a memory test to assess the effect of aging and diet on cognitive processes. Both young and older rats, in conditions of caloric restriction, showed a better memory of the location of the platform than animals aged in unrestricted feeding conditions. In addition, results indicated that the diet modified the levels of brain monoamines (dopamine, norepinephrine and serotonin) favoring neurotransmission in brain regions such as the prefrontal cortex or the hippocampus, which participate in memory formation. A positive effect of caloric restriction on the expression of glutamate neurotransmitter receptors was also found, especially in hippocampal regions.

The results of this work contribute to a better understanding of the beneficial effects of a calorie-restricted diet on brain aging and its ability to reduce the negative effects of aging on cognitive functions.