How Do Drugs Affect Our Brains?

The Neuron And The Synapse

The neuron is the building block of the brain. There are 86 billion neurons in our brain and those 86 billion neurons will be with you your whole life (unless you lose some neurons). Unlike other types of cells, the neuron can’t divide into multiple cells so the neurons that you are born with will stick with you for the rest of your life.  Currently, there is research on how to make the human body perform neurogenesis (this is the action of neurons dividing and replacing the former neuron). It's not just the brain that has neurons, areas such as the spinal cord, muscle tissue, olfactory area, gustatory areas, etc. contain large amounts of neurons.

In order for your brain to function, your neurons need to communicate with each other. Neurons communicate with each other in a tiny gap between 2 neurons called the synapse. Neurons send electrochemical signals across the synapse and those signals are called neurotransmitters. Some neurotransmitters such as GABA inhibit the receiving neurons to send the message to the next neuron but other neurotransmitters such as glutamate make the receiving neuron more likely to fire off that signal to the next neuron. The pre-synaptic neuron usually sends neurotransmitters into the synapse, then neurotransmitters bind to receptors on the receiving neuron which causes that neuron to either fire a response or completely deactivate the response. In a few circumstances, the presynaptic neuron may send a bit too many neurotransmitters, in that case, there are transporters that would send some of the neurotransmitters back into the presynaptic neuron. The communication surprisingly only takes 0.5 milliseconds! Although, when drugs enter the brain, they tend to mess up the unique nature of the synapse.

Cocaine 

Cocaine in the U.S. is an illegal drug that causes violent or life-threatening side effects among its consumers. This drug mainly affects the reward pathway in the brain which is commonly associated with happiness and pleasure. Typically when cocaine is consumed, the drug would quickly go to the brain and would start to cause trouble in the synapse in the brain, especially on the neurotransmitter, dopamine. In normal circumstances in the reward pathway, the pre-synaptic neuron would release a lot of dopamine and the transporters would absorb any unused dopamine back into the neuron so it can use it for the next interaction with other neurons. This is however not the case when you consume cocaine. This drug will usually block the transporter from absorbing the dopamine back into the neuron which in turn would make the synapse flooded with dopamine which causes the feeling of euphoria(pleasure). The feeling of euphoria makes Cocaine super addicting which is a serious problem in the U.S. Small amounts of cocaine usually make the user feel euphoric, energetic, talkative, mentally alert, and hypersensitive to sight, sound, and touch. The drug can also temporarily decrease the need for food and sleep.  Large amounts of cocaine can make people violent, and extremely alert, and their heart rate can increase substantially. This is why taking cocaine as a drug for no use is a bad idea.

Marijuana

Marijuana is one of the most addicting drugs in the U.S. Even though this drug can cause people to be violent or make people act weird, marijuana can technically kill you, it's not a fatal drug even if you take too much.  Marijuana is made out of TCH and CBD. TCH is responsible for the violent effects of marijuana while CBD is responsible for the nonviolent effects of marijuana. Also, marijuana typically affects the white matter tract the most in your brain. Marijuana affects the neurotransmitter anandamide because the molecular structure of TCH is extremely similar to anandamide Typically when the pre-synaptic cell in the synapse would release anandamide, the neurotransmitter would bind to endocannabinoid receptors (responsible for influencing neuronal synaptic communication and affects biological functions—including eating, anxiety, learning and memory, reproduction, metabolism, growth, and development), all in a hundredth of a second! This is however not the case when you consume marijuana, although some anandamide will go to its endocannabinoid receptor, some endocannabinoid receptors might mistake TCH as anandamide and the nature of TCH is to delay the time that it takes for the 2 neurons to communicate leading not slower learning. The white matter tract is responsible for learning and memory and this is the area where most of the anandamide and endocannabinoid receptors are densely located. Since during your kid and teenage years your white matter tract is still developing and taking marijuana could make it harder to learn something to remember something. This is why marijuana has a greater effect on kids and teens than adults. Also, when marijuana is consumed, it causes the feeling of euphoria and relaxation which makes it so addicting.

To add on, the long-term effects of marijuana include cognitive impairment, anxiety, paranoia, and increased risks of psychosis and hallucinations. This is why taking marijuana as a drug for no use is a bad idea.

Article by Agam Nanda

SOURCES:

https://nida.nih.gov/publications/research-reports/cocaine/what-are-short-term-effects-cocaine-use

https://nida.nih.gov/publications/research-reports/marijuana/how-does-marijuana-produce-its-effects

https://www.brainfacts.org/the-brain-facts-book