Growing up high: Neurobiological consequences of adolescent cannabis use

About one in five Canadian adolescents uses cannabis (19% of Canadians aged 15-19), and its recent legalization across the country warrants investigation into the consequence of this use on the developing brain. Adolescence is associated with the maturation of cognitive functions, such as working memory, decision-making, and impulsivity control. This is a highly vulnerable period for the development of the brain as it represents a critical period wherein regulatory connection between higher-order regions of the cortex and emotional processing circuits deeper inside the brain are established. It is a period of strong remodeling, making adolescents highly vulnerable to drug-related developmental disturbances. Research presented by Canadian neuroscientists Patricia Conrod, Steven Laviolette, Iris Balodis and Jibran Khokhar at the 2019 Canadian Neuroscience Meeting in Toronto on May 25 featured recent discoveries on the effects of cannabis on the adolescent brain.

Dr. Patricia Conrod, at Université de Montréal, studied the year-to-year changes in alcohol and cannabis use and cognitive function in a sample of adolescents consisting of 5% of all students entering high school in 2012 and 2013 in the Greater Montreal region (a total of 3,826 7th grade students). Students were assessed annually for 4 years on alcohol and cannabis use, and their cognitive function was evaluated using computarized cognitive tests. The researchers found substance use to be linked to low cognitive functioning, a finding that could be indicative of an underlying common vulnerability. Cannabis use was linked to impairments in working memory and inhibitory control, which is required for self-control. Cannabis use was also linked to deficits in memory recall and perceptual reasoning. Alcohol use was not linked to impairments in these cognitive functions, suggesting cannabis could have more long-term effects than alcohol.

Key brain area plays a crucial role in addiction

New research finds that the cerebellum, a large part of the human brain that scientists thought was primarily involved in motor control, may play a key role in reward-seeking and social behaviors. The findings may help inform future therapies for treating addiction.

Recent research has hinted at the fact that, in addition to movement, the brain’s cerebellum may also help to control cognitive functions, such as language, learning, and attention.

Now, scientists at the Albert Einstein College of Medicine in Bronx, NY, suggest that this area could also regulate reward-processing and addiction.

Full story at Medical News Today

Adolescent cannabis use alters development of planning, self-control brain areas

Adolescent marijuana use may alter how neurons function in brain areas engaged in decision-making, planning and self-control, according to researchers at the University of Illinois at Chicago.

The findings, which were presented at Neuroscience 2018, the annual meeting of the Society for Neuroscience, are the result of an animal model study focused on the structural development of the prefrontal cortex, or PFC, which controls high-level cognitive functions.

Within the PFC, a support structure called the perineuronal net forms a lattice of proteins around inhibitory cells, helping to secure their connections with excitatory neurons and regulate PFC activity. Perineuronal net formation is sensitive to drug use, but the effects of marijuana are not known.

Full story at Science Daily