An episode of brain inflammation early in life may lead to long-lasting changes in the brain that increase the risk of developing drug addiction during adulthood, a new animal study found. Brain inflammation is most often caused by head injury or a viral infection such as encephalitis or meningitis.
The research was presented at Neuroscience 2010, the annual meeting of the Society for Neuroscience, held in San Diego.
Senior author Lir-Wan Fan, PhD, of the University of Mississippi Medical Center, and her colleagues previously showed that adult rats exposed to lipopolysaccharide, a toxin produced by certain bacteria that triggers a strong inflammatory immune response, are more likely to exhibit addictive-like behavior in response to a dose of methamphetamine. In this new study, the researchers found that adult rats exhibited the same increased tendency toward an addictive-like response to methamphetamine even when their exposure to lipopolysaccharide — and the resulting brain inflammation — had occurred early in the animals' development. The response was greater in male than in female rats.
"Our findings suggest that early-life brain inflammation leads to long-lasting damage of the brain's reward system," said Fan. "But this damage may not become apparent unless later unmasked by exposure to an addictive drug, like methamphetamine," Fan said.
Research was supported by the National Institute of Health Human Development, the National Institute of Neurological Disorders and Stroke, the University of Mississippi Medical Center, and the Shin Kong Wu Ho-Su Memorial Hospital in Taipei, Taiwan.