Since the 1970s, scientists have known that human brains contain a group of receptors called cannabinoid receptors. These specialized brain cells are sensitive to compounds found in cannabis plants, and when they respond to these compounds it can have powerful effects on humans.A major breakthrough came when medical marijuana became legal in many countries around the world. The availability of this drug has led to an increased understanding about how cannabinoids affect humans and has allowed for people with certain health conditions or pain relief needs to get the help they need.What is the endocannabinoid system and why does it matterThe Endocannabinoid system is a system of receptors, cell types, and signal molecules that are present within our body. These receptors are found in the brain and other major organs of the body. The ECS’s sole purpose is to help control many bodily functions including mood, sleep cycles, pain sensation, appetite, and more. One of the most important functions of this system has been discovered to be in regulating stress levels in the human body. This discovery has led scientists to believe that everything from depression to chronic pain may be caused by an imbalance in this system.Cannabinoid receptors are one of the main groups of cell types found in the ECS. They allow for cannabinoids to bind with them and trigger a reaction from these cells. In human brains, cannabinoid receptors can be found on neurons that make up many different parts of the brain including those involved with motor function, cognition, memory processing, emotional responses, and sensory processing.There are two main types of cannabinoid receptors that are found in humans, one that is primarily involved with the psychoactive effects of cannabinoids (e.g., THC) and another that is primarily responsible for pain response. When humans use medical marijuana or cannabis products with high levels of THC, their brain has a powerful reaction that can help counteract pain, anxiety, or depression.The Endocannabinoid system is a fascinating human system that has just begun to be studied in depth. It’s discovery has led to increased knowledge about how cannabinoids affect the human body and also how medical cannabis can be used to treat many health conditions.The discovery of cannabinoid receptors in the brainScientists discovered cannabinoid receptors in the brain and found that compounds of cannabis, such as THC and CBD, activate these receptors.The discovery led to a better understanding of how cannabinoids affect humans. Medical use of cannabis has been legalised in many countries since then.Where are the cannabinoid receptors in my brain?Cannabinoid receptors can be found in almost every part of the brain. The CB1 receptor is found in higher concentrations in the limbic system and cerebellum, while the CB2 receptor is found in higher concentration in the immune system. There are also cannabinoid receptors outside of the brain which relate to the digestive and reproductive systems.How do cannabinoids affect my brain?When cannabinoids activate CB1, they can cause effects such as: reduced motor activity, reduced energy use, reduced memory and learning function and reduced decision making abilities and social behaviour. When cannabinoids activate CB2, they can cause anti-inflammatory effects and reduce neuropathic pain.Can cannabinoids treat medical conditions?Since the discovery of cannabinoid receptors in the brain, many studies have been conducted to see whether cannabinoids can be used to treat a range of different medical conditions. THC has been found to slow down the progression of Alzheimer’s and may also be useful in the treatment of multiple sclerosis, epilepsy and schizophrenia. CBD has been found to reduce seizures and there is some evidence that it could be used as an anti-psychotic drug.Other cannabinoids have been found to help with conditions such as diabetes, liver disease and obesity. However, more research needs to be done.How cannabinoids affect humans.Cannabinoids and the endo-cannabinoid system which they affect, can produce a variety of effects on humans. These include: reducing chemotherapy-induced nausea and vomiting, reducing anxiety, relieving chronic pain, reducing seizures in epileptic conditions, reducing nausea following treatment with cancer chemotherapy drugs or other types of anti-cancer treatments.For a long time it was assumed that cannabinoids acted as a chemical communication between cells, but recent research has shown that a second system of communication might exist.Endocannabinoids and cannabinoid receptors.Research into endo-cannabinoids started in 1988, when an endo-cannabinoid called Anandamide was found to be able to produce physical effects similar to those of tetrahydrocannabinol (THC), the psychoactive molecule in cannabis.Further research has found more of these endo-cannabinoids, but they are not only produced naturally inside the human body, there is evidence of them being synthesised by cells too. As well as physical effects on humans, their presence can also affect how the brain is stimulated by neurotransmitters .Endocannabinoids and the endo-cannabinoid system have been implicated in a wide range of processes in the human body. These include modulation of adult neurogenesis (production of new neurons in adults), angiogenesis (growth of new blood vessels from pre-existing ones) and neurodegeneration (a loss of neurons) that take place in response to stimuli like stroke or neuronal injury.Anandamide and 2-Arachidonoylglycerol (2-AG) are the two most well-known endo-cannabinoids, but others have been discovered too.Research into the roles that the endo-cannabinoid system plays in humans is still ongoing, but it looks increasingly likely that it will lead to new treatments for medical conditions which are resistant to conventional therapies.ConclusionThe endo-cannabinoid system is an intricate part of the human body’s natural responses to stress, pain relief and homeostasis. With so many countries legalising medical cannabis use since its discovery in the 1970s, it seems like we may be on the verge of a new era for this plant medicine. Given what we know about how cannabinoids affect humans and our understanding of their mechanisms in our brains, it would seem that there is still much more research yet to be conducted into these receptors which are found in most animal species including humans.