Male C57BL/6 mice that undergo maternal separation (MS) early in life demonstrate higher levels of anxiety upon reaching adulthood compared to normally reared offspring. This study reports that neonatal males and females that undergo MS have reduced mRNA levels of transforming growth factor-alpha (TGF alpha) in the prefrontal cortex, an area of the brain implicated in emotionality, compared to normally reared animals. TGF alpha expression was unaffected by MS in the hippocampus. These data indicate that MS leads to a brain region-specific suppression of TGF alpha expression early in development.