Brain scans reveal consuming cannabis as teen affects neuron communication

New Delhi, Oct 24 (PTI) MRI brain scans of teenagers have shown that those consuming cannabis had a thinner cerebral cortex, which is responsible for higher-level functions such as reasoning and decision-making, according to a recent study.
     Researchers found that tetrahydrocannabinol, or THC -- an active substance in cannabis -- caused a shrinkage of neurons forming the "network of antennae", which is critical for neurons to communicate with each other.
     This results in a weakening or thinning of certain regions in the cerebral cortex, which the researchers, including those from the Universite de Montreal, Canada, said was "bad news at an age when the brain is maturing".
     "If we take the analogy of the brain as a computer, the neurons would be the central processor, receiving all information via the synapses through the dendritic network," Tomas Paus, a professor of psychiatry and neuroscience at Universite de Montreal and lead author of the study published in The Journal of Neuroscience, said.
     "So a decrease in the data input to the central processor by dendrites makes it harder for the brain to learn new things, interact with people, cope with new situations, etc. In other words, it makes the brain more vulnerable to everything that can happen in a young person's life," Paus said.
     With commercial cannabis products containing increasing concentrations of THC, the researchers said it is imperative to understand how this substance affects brain maturation and cognition.
     "By analysing magnetic resonance imaging (MRI) scans of the brains of a cohort of teenagers, we had already shown that young people who used cannabis before the age of 16 had a thinner cerebral cortex," Paus said.
     In addition to MRI scans, the authors also analysed the effects of cannabis use in mice, which showed changes in how certain genes expressed themselves, affecting the structure and function of neurons and their interconnections, and resulting in a thinning of certain regions of the cortex.
     These genes were also found to be present in humans, particularly in the thinner cortical regions of the teenage participants who experimented with cannabis, the researchers said.

(This story has not been edited by THE WEEK and is auto-generated from PTI)