According to groundbreaking research from the University of São Paulo’s Ribeirão Preto Medical School (FMRP-USP), excessive stress during adolescence may lead to enduring alterations in gene expression within the brain, particularly genes governing bioenergy and mitochondrial function. These genetic changes, in turn, can influence the likelihood of developing behavioral issues and psychiatric disorders in adulthood.
The study, published in the journal Translational Psychiatry, offers a compelling view into the molecular underpinnings of stress’s lasting impact. “Like the human brain, the brain of an adolescent rat is highly plastic. This plasticity is seen at the molecular level and in terms of behavior,” reported Thamyris Santos-Silva, first author of the study. Such neuroplasticity, while a hallmark of adolescent development, also renders the brain particularly sensitive to environmental stressors.
The prefrontal cortex, crucial for regulating emotions and cognitive control in adulthood, was found to be exceptionally vulnerable to stress in adolescence. Rats exposed to a rigorous stress protocol displayed “a markedly poor behavioral profile, with anxiety, reduced sociability and impaired cognitive function,” according to Felipe Villela Gomes, a professor at FMRP-USP and one of the study’s authors. These behavioral impairments were indicative of deeper molecular disturbances.
Delving into the genetic layer, RNA samples from stressed rats were examined at the Behavioral Genetics Laboratory of the Brain Mind Institute (BMI) at the Swiss Federal Institute of Technology in Lausanne. This investigation revealed that the top ten genes affected by stress were associated with pathways tied to oxidative stress and mitochondrial function—critical components of energy production in the brain.
Mitochondria, the so-called powerhouses of cells, are essential for the energy that fuels neurons, which are integral to social behavior and stress responses. Notably, the research found that stress compromised oxygen consumption by mitochondria in the brain, indicating that mitochondrial function is a key player in the behavioral profiles observed.
Looking forward, Gomes suggested that their findings might help predict individual stress responses and the likelihood of psychiatric disorder development. Moreover, he proposed that “another route to advance the study would be to focus on genetic alterations, conducting tests to find out what happens when gene expression diminishes or improves.”