Those tense meetings and late-night projects at work might be doing more than ruining your day. Repeated stress can negatively affect how well you think and remember...which probably will just stress you out even more. Stress is a well-known trigger for mental illnesses, such as depression, anxiety and post-traumatic stress syndrome. Depression, for example, has been linked to elevated levels of the stress hormone, cortisol. The primary target for stress hormones in the brain is the prefrontal cortex, which lies in the front part of your brain. This area controls “executive” functions, such as working memory and decision-making. Previous studies have shown that chronic stress can cause changes in the prefrontal cortex as well as impair its functioning. The prefrontal cortex is especially sensitive to stress during adolescence, when the brain is still developing. In the current study, researchers found that repeated stress affected the working memory of rats by interfering with the connections between neurons in the prefrontal cortex. Even though the total number of connections—or synapses—remained the same, a drop in the activity of glutamate receptors on those neurons lead to the impaired memory. The researchers were able to block the dysfunction of the glutamate receptors by infusing the prefrontal cortex with a chemical called a protease inhibitor. This technique might someday offer a potential treatment for the effects of repeated stress on the brain.