Human reports as well as animal studies have recorded accelerated motor activity, learning and memory deficits in offsprings of mothers exposed to nicotine during pregnancy. This study, conducted by Dr. T. S. Roy, Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India, is the first to investigate actual physiological changes of the cerebral cortex of rats after prenatal nicotine exposure. Several groups of experimental rats were exposed to varying levels of nicotine reaching up to that experienced by a heavy smoker. Animals were examined at different periods after birth. Observable effects included significantly reduced thickness of the cerebral cortex, smaller cerebral cortex neurons, and reduced brain weight. Also noted was an overall decrease in "dendritic branching" (connections to other brain cells), as seen in the camera lucida drawings at right. The present study also shows that the greater the dose of nicotine, the greater the biological effects upon the offspring. This research provides an excellent biological model to support the many other studies linking increased hyperactivity, attention deficits, lower IQ, and learning disabilities in children with parents who smoked during pregnancy.
post by, Lai
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