A recent study by Inserm in collaboration with the Spanish University of Salamanca shows that exposure to cannabis alters glucose metabolism in the brain, leading to behavioral changes related to sociability. Specific cannabinoid receptors, located in star-shaped cells of the central nervous system called astrocytes, are believed to be one of the causes of this relationship.
The study, published in the journal Nature, follows the discovery in 2012 of endocannabinoid receptors located on the membrane of mitochondria, the intracellular organelles whose role is to provide cells with the energy they need.
Among other functions, these cells play a very important role in the brain’s energy metabolism.
Given the importance of astrocytes and the use of energy for brain function, we wanted to understand the role of these special cannabinoid receptors and the consequences for the brain and behavior when exposed to cannabis,” explains Giovanni Marsicano.
The researchers then gave THC to mice and observed that persistent activation of mitochondrial cannabinoid receptors in astrocytes resulted in a cascade of molecular processes leading to a dysfunction of glucose metabolism in astrocytes.
The ability of astrocytes to convert glucose into “food” for neurons was then reduced. In the absence of additional energy intake, the functioning of neurons was compromised in animals, with a negative impact on behavior. In particular, social interactions decreased up to 24 hours after exposure to THC.
Our study is the first to show that the decrease in sociability sometimes associated with cannabis use is the result of altered glucose metabolism in the brain. It also opens up new avenues of research to find therapeutic solutions to alleviate some of the behavioral problems resulting from cannabis exposure. Also, it reveals the direct impact of astrocyte energy metabolism on behavior,” explains Marsicano.