New research out of Western University is shedding light on how cannabis use during pregnancy can negatively affect brain development in babies.
Western researchers launched the study to fill in gaps in understanding surrounding prenatal cannabis exposure.
“A lot of people don’t understand that prenatal cannabis exposure hasn’t been that well researched, so we don’t really know the full impact of it on the developing brain,” said Lead Researcher Mohammed H. Sarikahya, a Western PhD student.
Despite that, expectant mothers often believe cannabis use is safe because it is a natural, non-pharmacological option to reduce symptoms of nausea and anxiety.
For the study, researchers exposed pregnant rats to tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis. They then examined the offspring of the exposed rats, finding severe impacts on the rodents’ developing brains. The THC-treated rats had major losses in the levels of omega-3 and omega-6 fatty acids in the brain, especially in areas responsible for processing emotion and anxiety.
“We were very surprised at the magnitude of the impact on the brain’s fatty acid signaling pathways, especially given the critical importance of this system on normal brain development,” said Research Supervisor Steven Laviolette, who works in the department of anatomy and cell biology at the Schulich School of Medicine & Dentistry.
Researchers also noted a difference in how male exposed rats reacted compared to their female counterparts. Males exhibited a hyperactive dopamine system into adulthood, while females dopamine system eventually levelled out. Dopamine is critical in helping to regulate emotion and anxiety.
“What we saw was that only the males exhibited this anxiety,” said Sarikahya. “The females weren’t completely unaffected. What we saw at childhood was that they also had severe deficits to their brain’s fatty acid profile. At some point between childhood and adulthood they are able to correct these fatty acid disturbances.”
He added that the implication of the disturbances so early in life are “worrisome” due to their role in brain development and later-in-life function. He also believes there could be additional consequences of prenatal cannabis exposure for the females that has yet to be discovered.
Researchers now intend to examine how prenatal cannabis exposure may be detrimental for addiction.
“What we’re seeing is the addiction pathways are hyperactivated in the offspring following the exposure. That’s something we are going to explore in order to see how their sensitivity to various drug reward stimulus might be changed during adolescence and adulthood,” said Laviolette.
The results of the study were eNeuro, the journal of the Society for Neuroscience.
