Prenatal nicotine exposure alters neuroanatomical organization of the developing brain.

Although there has been considerable research conducted regarding the long-term effects of prenatal exposure to nicotine, there has been little examination of how this experience influences brain development. This study was designed to examine if there are morphological changes (dendritic branching, dendritic length, and spine density) in medial prefrontal cortex, orbital frontal cortex, parietal cortex, and nucleus accumbens associated with exposure to nicotine during gestation. Nicotine or saline was administered to pregnant Long Evans dams for the duration of pregnancy. Golgi-Cox techniques were used to examine neuroanatomy of offspring at postnatal day 21. The dendritic changes identified in rats exposed to nicotine prenatally resembled neuroanatomical changes that are identified in rats administered with nicotine in adulthood. Of the 18 anatomical parameters measured, 11 exhibited significant modification, with two parameters apical and basilar spine density in parietal cortex demonstrating sex-dependent modification. These early changes in anatomy and behavior have important implications for later plasticity and long-term well-being.