Gender- and age-specific impairment of rat performance in the Morris water maze following prenatal exposure to an MRI magnetic field.

We examined the effects of prenatal exposure (40 min/day, gestation days 12-18) of rats to a magnetic resonance imaging (MRI) magnetic field (MF) on their performance in the Morris water maze. At 2 months of age, female rats showed impaired performance. The animals spent longer time swimming and used inefficient strategies. However, no significant effects on maze performance were observed at 1 and 5 months of age. No evident maze performance deficit was detected in male rats prenatally exposed to the magnetic field. Thus, we conclude that prenatal exposure to MRI magnetic field induces cognitive/behavioral deficits in female rats at a specific age.