When mothers use cocaine during pregnancy, the exposure of the developing brain to the substance can cause specific neurological and behavioral abnormalities, according to a study released on June 9, 2008 in the open access journal PLoS Medicine.

Cocaine use is a factor in many hundred thousand pregnancies per year in just the United States, and the resulting effects on fetal development often include disorders of the central nervous system. In this study, Chun-Ting Lee and colleagues at the U.S. National Institutes of Heath delved into the mechanism by which cocaine affects fetal brain development.

The team discovered that one major byproduct of cocaine metabolism interferes with the cell signalling substance Cyclin A.  Specifically, this curtailed neuronal development in neonatal exposure to cocaine. The cellular mechanism behind this was based on oxidative stress within the cell’s endoplasmic reticulum, which affects protein production.

By treating pregnant rats with the stomach acid drug cimetidine, which also interferes with the enzymes that metabolize cocaine, the researchers were actually able to work against this inhibition of neural development that was caused by cocaine exposure. As a result, there is some promise that treatments that block the effects of cocaine on cyclin A could be one method of protecting fetal development when a pregnant woman is unable to discontinue cocaine use. According to the researchers, futher research is still necessary to determine if this method could be safe and effective in humans.

Steven Hyman of Harvard University contributed a related perspective in which he states his enthusiasm about the findings, but adds that there is much “complexity of factors that might contribute to cognitive and emotional abnormalities in children exposed to cocaine and other dangerous drugs in utero.”

A mechanism responsible for the inhibition of neural progenitor cell proliferation by cocaine.
Lee C-T, Chen J, Hayashi T, Tsai S-Y, Sanchez JF, et al.
PLoS Med 5(6): e117.
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Written by Anna Sophia McKenney