It has been known for a while that too much stress can be bad for your health. A new study now shows that it can affect your brain too. Research through a collaboration between Rockefeller University and Cornell University suggests that stress can been linked to harmful changes in some brain structures. Sometimes these brain changes can be advantageous, such as making new synaptic connections to remember and learn from a stressful, life-threatening event. However, some changes can be detrimental.
The project has identified a protein possibly involved in remodeling the brain under stress. It was found that the brains of mice lacking the protein called brain-derived neurotrophic factor (BDNF) look like the brains of stressed mice. The study examined changes in the neurons of the hippocampus, a brain area important in memory, mood, and cognition. When normal mice were stressed through confinement to a small space, the tiny projections on their neurons called dendrites retracted in the hippocampus. The hippocampus itself was also reduced in overall volume. The study compared these mice to other mice that were missing a copy of the gene that produces BDNF. It was found that these genetically-altered mice had brains resembling those of stressed mice.
Not only does this finding show that stress can produce brain changes. Bruce McEwan of Rockefeller University suggested that BDNF also may be “one of the proteins that play a role in mediating the brain’s plasticity.” This holds promise for a better understanding of the role of neuronal remodeling in the hippocampus and its importance in memory and emotion.
On April 1, 2010, scientists funded by the Biotechnology and Biological Sciences Research Council at the University of Birmingham uncovered a gene that is strongly related to the lifespan in Caenorhabditis elegans (C. elegans) and three of its close relatives. Scientists used longevity of life, immunity, and resistance to stress as the main determinants of the worms lifespan.
Head researcher Dr. Robin May explains the purpose of their research: “We wanted to find out how normal ageing is being governed by genes and what effect these genes have on other traits, such as immunity.” To do this, they looked at a gene that has been known to play an important role in the ‘dauer’ stage of development and influence the longevity of life in worms, gene DAF-16.
To figure out the exact role this gene plays in the worms lifespan, researchers sought out the relationship between the worms lifespan/resistance to stress and that its expression of the DAF-16 gene. To induce stress in worms scientists exposed “them to high temperature, heavy metals and a range of bacterial and fungal diseases.”
Their results were very promising. As they expected, the DAF-16 gene and it’s expression in worms positively correlated to their lifespan, and, in general, “higher levels of DAF-16 activity correlated with longer life, increased stress resistance and better immunity against some infections.”
Although this study was performed on worms, scientists have high expectations for the implications in humans. Researchers say that “it is possible that this knowledge could open up new avenues for altering ageing, immunity and resistance to stresses in humans.”