The research, by a psychologist Mary Meagher from the College of Liberal Arts and an immunologist Jane Welsh from the College of Veterinary Medicine at Texas A&M, shows that exposure to prolonged maternal separation during the first two weeks of life altered immune, endocrine and behavioral responses to acute "Theiler's virus" infection in mice.
Theiler's virus attacks the central nervous system during the first few weeks of infection, which is accompanied by polio-like symptoms. If the virus persists in the central nervous system, a subsequent chronic phase of the disease develops which is similar to multiple sclerosis in humans.
Researchers use Theiler's virus to investigate the role of stress in autoimmune diseases, or diseases that cause the body to attack its own cells as if they were foreign pathogens - a similar process occurs in multiple sclerosis, Meagher explains.
In this study, infant mice that were subjected to maternal separation and later contracted Theiler's virus as adults demonstrated an increased amount of the virus, altered behavioral signs of infection and had a more difficult time getting over, or "clearing," the infection in its acute stage than did mice that were not separated from their mothers and later contracted the disease.
Such results, Meagher explains, suggest that the immune system is undergoing a critical period of development early in an organism's life, and that a considerable stressor can cause significant life-long alterations to the immune system that increase its vulnerability to diseases of the central nervous system later in life.
Previous studies have shown stress to play an important role in the contracting of multiple sclerosis in humans, finding that 80 percent of adults who contract the disease reported a stressful life event two years before its onset. Meagher's research takes that exploration a step further, examining how early life stress alters vulnerability to later viral infections of the central nervous system.
Her research is being conducted as part of the "Recovery of Function" program, a new interdisciplinary program that enrolls about 30 graduate students and is composed of 14 faculty members from seven departments in four colleges at Texas A&M - the Colleges of Liberal Arts, Veterinary Medicine, Agriculture and Life Sciences, and Medicine. The program focuses on research interests such as the loss and recovery of neural function following injury, infection, aging and neurodegenerative disease in laboratory animal models. In addition, the program is affiliated with several off-campus research centers in Houston, Galveston and Dallas that focus on both laboratory and clinical research.
Understanding how early stress affects the developing immune system could lead to interventions that prevent or reverse the harmful effects of newborn stress on disease predisposition, Meagher says. Some treatments could possibly include antidepressants and/or teaching coping mechanisms for individuals who are more likely to be susceptible to the disease, she adds.