A growing number of women are using marijuana as a treatment for morning sickness during pregnancy, and a team of researchers at Auburn University set out to investigate the potential impacts. The experts found that marijuana alters complex connections between nerves in the hippocampus, which is the brain’s center for learning and memory.
While previous studies have already tied marijuana use during pregnancy to children born with learning and memory impairments, the current study is providing brand new insight into how cannabis exposure affects the brain of a developing fetus.
“The findings from this study will serve as an excellent premise for future interventions to restore memory in children exposed to cannabis during pregnancy, and for the first time, identify a specific mechanism by which learning and memory impairment occurs and how this impairment can be ameliorated,” said study co-author and graduate student Priyanka Das Pinky.
A separate study recently found that marijuana use during pregnancy increased by 62 percent between 2002 and 2014.
“Based on our research and the previous existing findings in the field, it can be said that using marijuana during pregnancy would not be a wise choice,” said Pinky. “However, it is also notable that the observed effect in the offspring can vary according to their age and according to the trimester during which they were exposed to the drug as well as dose and route of administration of the drug.”
The research team exposed pregnant female rats to a synthetic compound equivalent to a dose of moderate-to-heavy marijuana use in humans. Among the resulting offspring, they found that connections between the nerves in the hippocampus were reduced compared to baby rats who were not exposed to the synthetic cannabis.
Further analysis revealed that the root of the problem was a reduction in neural cell adhesion molecules (NCAM), which are critical for maintaining the strength of neural connections.
“It is still very early to come up with a conclusion about the possible safe use of marijuana during pregnancy,” said Pinky. “More research is needed to evaluate the exact mechanism by which NCAM and/or its active form is modulating cellular effects while focusing on target specific drug development for amelioration of the observed cognitive deficits.”
The research will be presented at the American Society for Pharmacology and Experimental Therapeutics annual meeting during Experimental Biology 2019.