In the first stage, the scientists analyzed brain MRI data from adolescents under 16 who had used marijuana. They discovered a finer cortex structure in these adolescents. This data was very useful, but it did not allow them to draw any conclusions about the causal relationship between cannabis and brain cell function, so the scientists turned to preclinical models. The results were published on the University of Montreal website.
Experiments showed that tetrahydrocannabinol (THC) altered the expression of genes that influence the structure and function of synapses and dendrites. This resulted in signs of atrophy, which explains the thinning of the cortex in adolescents.
Among the main consequences of cortical thinning in the developing brain, scientists highlight difficulties in learning and interacting with people, as well as coping with new situations. "In other words, it makes a young person's brain vulnerable to everything that will happen to them later in life," concluded the study's author, Thomas Paus.
In another study, scientists previously discovered that cannabis leaves a unique DNA signature. Smoking marijuana has been shown to affect mitochondrial and immune function and can alter the body's biological processes.
