Antidepressants rejuvenate the brain, but is it good?
For a long time, the process of brain development and maturation was considered unidirectional, characterized by a gradual decrease in the plasticity of the cells involved in it. The possibility of returning the brain to a younger state was not even considered. However, Japanese researchers from Fujita University of Health, working under the guidance of Dr. Tsuyoshi Miyakawa, have demonstrated that long–term use of one of the most popular antidepressants – fluoxetine - can induce the transition of certain types of neurons in the prefrontal cortex of adult mice to a state corresponding to a younger age. Fluoxetine, known under such brand names as prozac, sarafem and fontex, belongs to the class of selective serotonin reuptake inhibitors.
As part of the study, the scientists gave male mice intraperitoneal injections of fluoxetine at a dose of 15 mg/kg of body weight per day for 3 weeks. The immunofluorescence analysis carried out at the end of the experiment showed that, compared with the brains of the control group mice, reduced expression of parvalbumin, calretinin and somatostatin, markers of maturation of a certain type of GABA–ergic (GABA- gamma–aminobutyric acid) intermediate neurons, was recorded in the prefrontal cortex of the experimental animals. At the same time, an increased expression of markers of young immature neurons was detected.
The occurrence of such a condition, called "iYouth" (from the English "induced-youth" – induced youth), under the influence of fluoxetine was previously demonstrated by the authors and other groups of researchers for the dentate gyrus of the hippocampus, the amygdala and the visual cortex of the brain. Which was found to be associated with the plasticity of certain types of neurons. The authors demonstrated for the first time the possibility of transition to the "iYouth" of the prefrontal cortex, which provides such important brain functions as working memory, decision-making, the manifestation of basic personality traits and social behavior, as well as involved in the development of psychiatric diseases caused by violations of these functions.
Rejuvenation of neurons in this region of the brain may underlie the therapeutic effect of fluoxetine. On the other hand, some undesirable aspects of drug-induced pseudo-youth may be the cause of certain behavioral side effects of therapy, such as aggression, cruelty and the development of psychosis, which have recently attracted a lot of attention from the public and specialists.
An interesting fact is that, according to previously published data, postmortem analysis of the brain of patients with schizophrenia revealed a decrease in the markers of neuronal maturation considered in the work in the prefrontal cortex. This suggests the existence of a parallel with the side effects of fluoxetine, but the final conclusions are still far away. Scientists have yet to understand the molecular mechanisms of "induced youth", as well as its differences from the real youth of the brain. Perhaps in the future, the answers to these questions will revolutionize the prevention and treatment of various neuropsychiatric diseases and will improve the quality of life of the aging population.
Article by Ohira K et al. Chronic fluoxetine treatment reduces parvalbumin expression and perineuronal nets in gamma-aminobutyric acidergic interneurons of the frontal cortex in adult mice is published in the journal Molecular Brain.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Medical Xpress materials:
Antidepressant drug induces a juvenile-like state in neurons of the prefrontal cortex.
06.11.2013