Dude…where’s my memory? It sounds funny, but new research on the effects of cannabinoids on the brain warns that memory loss can be the result of using cannabis, but turning off a chemical reaction to pot in the brain could allow the plant to be used more efficiently for certain medical conditions. Scientists have known for centuries that cannabis, (pot, marijuana, weed) changes the brain. If it didn’t it might not be so controversial (and in some places, popular).
After the last election the numbers were as follows: 28 states plus the District of Columbia now have laws that allow marijuana for medical use. 4 states allow pot to be used recreationally and other states have decriminalized its use and possession. Like anything else though, the safety of the plant for medical use and recreational use has been the subject of much debate. It comes down to the cellular mechanism of cannabinoids in the brain. In science for every action there is a reaction and that is what scientists in Spain investigated recently.
In the brain, cannabinoids attach to CB1 receptors located on the nerve endings of neurons. This pairing up then inhibits signals sent between neurons via neurotransmitters and the result can be memory loss. Research of the last decade has shown that CB1 receptors are also located in another part of nerve cells, the all important mitochondria. Mitochondria is known as “the powerhouse” of the cell, providing energy, so when something interferes with that process, the results can be neurological deficits or disease.
A team led by Dr. Giovanni Marsicano of the University of Bordeaux and including neuroscientists Nagore Puente, Leire Reguero, Izaskun Elezgarai and Pedro Grandes from the Department of Neurosciences of the University of the Basque Country Faculty of Medicine and Nursing and of the Achucarro Basque Center for Neuroscience found that memory loss, which is associated with cannabis use, is eliminated when the CB1 cannabinoid receptor reaction in the mitochondria of the hippocampus is shut down. When the researchers were able to genetically eliminate CB1 receptors located in the mitochondria of the hippocampus, memory loss that would normally have occurred was avoided and there was no decrease in cell signaling and neurotransmitter activity.
The research was able to illustrate exactly how memory loss is related to the celluar activity of the CB1 receptors in this new location of the hippocampus mitochondria. The result of this process is that cell respiration suffers and that impacts brain function. Similar action occurs in the skeletal and cardiac muscle according to earlier research by this same team, but the connection to the impact of this cellular process to the brain was a first.
In a press release Dr. Grandes said, "Mitochondrial malfunctioning could have serious consequences for the brain. For example, chronic mitochondrial dysfunction is involved in the pathogenesis of neurodegenerative diseases, strokes or disorders associated with ageing. However, the involvement of the acute variation in mitochondrial activity in higher brain functions, such as memory, was unknown. So this research has revealed that the CB1 cannabinoid receptors in the mitochondria regulate the memory processes by modulating mitochondrial energy metabolism.”
Rather than the news being just another warning on marijuana use and cognition, the team hopes that their findings will result in treatments that could shut down the negative impact of the CB1 receptors on memory. If the negative effects of the plant were mitigated, pot could be used medically without patients have to suffer the side effect of significant memory loss. The video below explains more about this new understanding of the results of marijuana use on brain function.