The Fear
Cannabinoids have been making quite a stir in America long before the the active component, THC, was discovered in the 60’s. Reefer Madness has been the fear of parents and school teachers since the 30’s and hasn’t let up much since. However, it was not till the 90’s that researches discovered the reason for marijuana’s effects was due to natural cannabinoid pathways already working in our bodies and that these pathways have mechanisms that protect the brain. I have a feeling that many of the proponents supporting the fear of reefer madness would be shocked and disbelieving about the neuroprotective work done by endocannabinoids.
Cannabinoids, the Brain’s Knight in Shining Armor?
The review paper we read for this week listed a number of instances where endocannabinoids protect the brain from external and internal damage. Behavioral changes and memory loss may be prevented by increasing the duration endocannabinoids remain active in the brain., while THC administration has been shown to reduce neuron loss and brain damage in ischemia models. These are just a couple of examples and are both carried out by the action of endocannabinoids, but in very different ways.
Excitotoxicity protection
Endocannabinoids have the role of protecting the brain from its own chemicals. The brain uses chemicals released from brain cells, neurons, to process and pass on information about the body. One of these important chemicals is glutamate which excites the places in the brain where it is released in order to pass on information from neuron to neuron until it reaches the target area that will process the message and carry out the action to react to that message. However, when there is too much glutamate being released by neurons it creates a state of excitotoxicity, or basically brain hyperactivity, which can have results as severe as seisure. When cells process that there is too much glutamate being released, endocannabinoids are released to stop the release of glutamate. This can greatly curb the problems that may arise from excitotoxicity.
Endocannabinoids are Making the Microglia Lazy
In the event of a trauma or stoke in which bleeding takes place in the brain there is potential for huge brain damage. The endocannabinoid system also has a procedure for helping to protect and repair the cells within the brain. There are a certain type of cell, the microglia, that act to repair damaged cells. When an area of the brain is damaged, these microglia congregate in that area to repair the damage. Unfortunately, when these cells start working in large numbers for long periods of time they produce waste that can be as damaging as the problem they had congregated to fix. This is where endocannabinoids come into the picture. They connect to these microglia and stop some of them from working. This creates a balance so that there are enough microglia to do their work without overdoing it and causeing damage themselves.
If Endocannabinoids are so Great, What’s the Problem?
The problem is actually quite similar to the problem the microglia can cause in the brain. By overcompensating, it is easy to do more harm than good. If endocannibinoids are given free reign, they can likely cause as many problems as when glutamate isn’t controlled. In other words, it appears that balance is the ticket. Most humans naturally have a proper balance of cannabinoids without taking a huge amount THC in the form of marijuana or even supplements of natural endocannabinoids. In the same vein though, there are people with imbalances that may be helped by prescriptions that increases the action of cannabinoids in the brain. This is why further research into endocannabinoids is necessary, to help provide information about what a proper endocannabinoid system looks like. With this information, medications may be created that can help correct imbalances and improve people’s lives.
Cannabinoids, the fear and perhaps, the promise.
