Most Medical Drugs, Narcotics, and Alcohol all change brain function is some way or another. Usually they interfere with the neurotransmitters in the brain, replacing your natural ones with whatever substance was ingested.


Scientist consider a drug "addictive" if it causes a fluctuation in the amount of dopamine the brain creates. Dopamine (C8H11NO2) is a chemical made by the brain that triggers senses of pleasure. The excess in the brain is what causes the sense of a "high". Some drugs act as neurotransmitters that trigger the brain to fill with an excess of Dopamine. Other drugs, such as opiates (heroin, morphine) inhibits the inhibiters of endorphins in the brain, the user has a feeling of pleasure with the excess of them. Cannabis binds to a molecule called anandamide, which effects mood, memory, appetite, pain, and emotions.



(Warning: Video contains drug usage. Don't do drugs kids)


Cocaine Molecule


Dopamine Molecule

Christopher Fox: Cocaine does have the short term affect on the brain, what is the long term affect? I have heard that after too many uses of cocaine and having too much dopamine cause the user to not have the ability to "be happy" anymore. Do you know what makes this happen?

Lauren - As well as short-term effects, continual usage of cocaine also has many long-term ones. Along with major health concerns, cocaine can cause addiction and even tolerance after just one use. Cocaine increases the amount of dopamine and prevents it from exiting brain circulation. With continued use, the dopamine receptors become overwhelmed and eventually desensitize. This is called tolerance. To obtain the same effect, a user will have to continue increasing the amount of the drug. However, A user cannot obtain complete tolerance of the drug and increasing the amount each time can eventually lead to overdosage.



There are many types of alcohol. An alcohol is an organic compound that has little of no ionization of hydrogen. The alcohol that is consumed by people is called ethyl alcohol, or ethanol (CH3CH2OH). An Ethanol molecule consists of two carbon atoms, two hydrogen atoms and an oxygen atom.


Alcohol on the brain - Acute effects from Sam Scopelliti on Vimeo.

Bianca Villamar- "Alcohol causes an increased flur of chloride ions." What exactly is in alcohol that causes an increase in chloride ions? Why does reduced signaling lead to an erratic change of behavior?

Lauren - Assuming that you are referring to the video above, I'm going to walk through it and hopefully answer your questions. Two of the things that the video shows are GABA neurotransmitters and Chloride ions. GABA or gamma-aminobutyric acid (C4H9NO2) is the brain's major neurotransmitter. Recall that a neurotransmitter is a chemical that allows for transmissions and signals across neurons in the brain. This GABA neurotransmitter isgoing to link up with and activate what is called a GABA receptor. The GABA receptors play a major role in memory, mood, emotion, and pain. When the GABA neurotransmitter binds to its receptor in the brain, it opens a "chloride channel". Normal amounts of the ion cause the transmissions between neurons to continue as normal. However, the ethanol molecule in the brain causes an excess of Cl- to pass through this "channel". The negatively charged Cl- causes the already negatively charged receptor to become hyperpolarized (super negative). This inhibits the transmissions across the neuron. Inhibiting neuron transmission from the GABA receptor causes fluctuation in memory, mood, emotion, and pain. This is what leads to the erratic behavior.


When a cell is damaged in the body, it releases chemicals that bind to enzymes which then are sent to the brain to give the reception of pain. Enzyme molecules have what is called a lock and key model. They have a special 3D structure that only certain chemicals can fit in. Pharmaceuticals, such as aspirin and ibuprofen, are designed to fit in the enzymes' binding sites, obstructing the chemical from binding to its enzyme carrying out the pain reception. Drugs can either prevent an enzyme from having its psychological effects, or they can cause it to become over-active. Some drugs bind to receptors in the brain rather than enzyme binding sights. Drugs such as morphine (C17H19NO3) attach to the receptors in the brain that sense pain, causing the the intensity of the perception to lessen.


Olivia D. - What is in alcohol and certain drugs that makes it so addictive? Is it what the substances are made of or how they are arranged?

Lauren - What cause addiction in alcohol is the fact that after a while, the GABA becomes dependent on the alcohol for it to even function properly, causing the body to actually begin to need the alcohol. This is also what causes withdrawal, function is impaired when alcohol is not present.

Would drugs that aren't as "hard" as cocaine, such as marijuana or tobacco, have the same affect on the dopamine levels in the brain? I know that tobacco affects dopamine levels creating its "buzz" and also negatively affect the lungs; in your opinion, would this make tobacco or cocaine worse in terms of affects on the brain's nerve cells?
-Cole K.