Marijuana can have a variety of effects on your brain, such as euphoria, a sense of relaxation, and heightened sensory perception. If you’re reading this, chances are that you have experienced some of these effects before.
Every individual will have a different set of reactions to marijuana culminating in a unique experience. Ultimately, though, the underlying biological mechanisms driving your subjective experience are shared.
The mechanisms by which marijuana can alter mood and perceptions are fascinating. At a molecular level, THC’s chemical structure bears resemblance to a naturally produced compound in the brain known as anandamide, or AEA (Scherma, Nature, 2018). This structural likeness allows THC to bind to the CB1 receptors in your brain that anandamide would normally bind to and in order to produce its rewarding, mind-altering effects. In fact, “ananda” is derived from the Sanskrit word for “internal bliss”!
CB1 receptors are found in higher clusters in specific regions of the brain. When cannabinoids bind to these receptors, they inhibit the release of certain neurotransmitters that your body typically produces–including acetylcholine, dopamine, serotonin, and glutamate—to regulate a host of functions within your nervous system.
Specific areas of the brain which contain CB1 receptors include:
- The basal ganglia: this area of the brain is responsible for movement and also houses your “reward system”, which explains why marijuana may lead to a sensation of slowness, euphoria, and an increased response to pleasurable activities such as eating and sex. When you use, THC acts like anandamide, and stimulates neurons in your reward system to release more dopamine than what your brain normally accustomed to.
- The prefrontal cortex: also known as the PFC, this area is responsible for higher-order brain functions such as inhibition and executive processing, which explains why you may experience disinhibition and altered decision-making abilities while high.
- The cerebellum: the cerebellum is responsible for coordinating smooth body movements. Feeling unbalanced, uncoordinated, or otherwise off-kilter when you’re under the influence is in part through marijuana’s actions on the cerebellum.
- The hippocampus: this brain territory is the core of learning and memory, which explains why marijuana may lead to short-memory impairment.
Many people experience pleasant cognitive effects, such as:
- Increased relaxation
- Altered perceptions
- Feeling as though time is slowed down
- Colors appearing brighter
- Enhanced appreciation of visual details
- Enhanced perception of noises and sounds
- Enhanced appreciation of music
- Enhanced taste
However, some people may experience more negative cognitive effects with marijuana. This is especially true if you are dependent, or if the marijuana you consume is of unexpectedly high potency. Factors like inexperience will put you are higher risk for consuming too much and precipitating a bad trip. These potential negative cognitive effects include:
- Increased appetite
- Nausea/Stomach Upset
- Lack of motivation
- Attention and processing speed deficits
- Memory impairments
- Impaired movement and movement coordination
Marijuana’s effects on your nervous system are therefore wide-ranging and vary dramatically between users. After all, THC isn’t the only neurotransmitter at play. Adding to this, your subjective experience is inevitably influenced by host of other factors, including your physical environment and your pre-existing mood state.