Findings from the National Institute of Mental Health may help to explain the reason females seem to have increased vulnerability to some conditions. The studies looked at the rat brain in relation to stressors. The rat brain is reportedly quite like the human brain in some respects so tends to work well with research studies, the results of which may apply to human brains. Reportedly, when the male brain is under stress, some of the receptors on the cell surface for stress hormones tend to retreat into the cell, making the brain less stress reactive. The opposite happens in the female brain. "Even in the absence of any stress, the stress-signaling system in the female brain appears to be more sensitive from the start." The receptors remain exposed on the cell surface, allowing CRF (corticotropin releasing factor) to persist in its effect. Thus, females may be more vulnerable to at least some stress-related disorders. Learning to manage stressors effectively is important for all brains. Apparently it may even be more important for a female brain.