Experts know that smoking during pregnancy increases risks for premature birth, miscarriage and low birth weight of infants, but also for tobacco and alcohol use and nicotine addiction of offspring later in life. With the aid of a 2010 NARSAD Independent Investigator Grant from the Brain & Behavior Research Foundation, Sarah Leibowitz, Ph.D., of the Rockefeller University, and her colleagues, have discovered a reason why children exposed to nicotine in the womb are more susceptible to addiction. The results were published August 20th in the Journal of Neuroscience.
In previous work, Dr. Leibowitz determined that, in rats, exposure to fat and alcohol in the womb leads to overconsumption of these substances in adolescence. She received her NARSAD Grant to try to better understand how and why this also happens with nicotine. The study involved injecting pregnant rats with small amounts of nicotine (equal to one cigarette a day in a pregnant woman) and analyzing the brains and behavior of the offspring.
The researchers found that, in the offspring of the nicotine-exposed rats, there was an increase in production of certain neurons in the amygdala and hypothalamus which produce hormones and neuropeptides that stimulate appetite and increase food consumption. Ultimately, this had long-term effects on their behavior―as adolescents, they not only self-administered more nicotine, but also ate more fatty food and drank more alcohol. Fellow NARSAD Grantee, George Koob, Ph.D., of the Scripps Research Institute in La Jolla, California, says the results of Dr. Leibowitz’s research highlight the toxic effects of nicotine on brain development and that this study casts new light on the role of these neuropeptides in reward and motivation. Dr. Leibowitz and her colleagues are now exploring ways to reverse the effects of prenatal exposure to nicotine and similar substances in order to prevent future addiction and obesity.
Read more about this study in Nature
Read the abstract of this research