Answers to submitted questions will be answered and updated hopefully on a weekly basis. Nicholas will try his hardest to answer in a timely manner. Some responses may answer multiple questions that I grouped together. Check out what other people have asked first! Your burning question might have already been answered! ---Science Penpals
Update from Nicholas, Nov. 13, 2019: I would like to apologize, our automatic notification system was not working so I didn't realize that I had received new questions. I will be responding to these questions this week!
1. Why does cocaine trigger the brain cell? -Shyloh & Lathan, NM
This video, produced by the National Institute on Drug Abuse, may be helpful as a starting point.
Cocaine alters the activity of brain cells by changing how the brain responds to chemical signals known as “neuromodulators”. Within the brain, small clusters of cells produce neuromodulators such as dopamine, serotonin, and norepinephrine. Although these cells reside primarily in the middle of the brain, they communicate with many other cells throughout the brain by sending out long, wire-like structures known as “axons”. Neuromodulators are released at the ends of these axons, where they traverse a specialized junction between cells called the “synapse”.
The targeted brain cells detect the neuromodulator via specialized proteins known as “receptors”. Once a neuromodulator binds to a receptor, chemical pathways within the cell trigger, which can then alter the cell’s activity patterns.
What happens next? As long as neuromodulators are floating around in the synapse, they can continue to activate receptors on the target cell. Unless you have a way of eventually getting rid of the neuromodulator, the target brain cell will keep getting triggered by the same signal over and over. Brain cells normally deal with this problem in one of two ways: they can either gobble up the neuromodulator to remove it from the synapse in a process known as “reuptake”, or they can destroy the neuromodulator altogether. Cocaine acts by blocking the proteins involved in the reuptake of neuromodulators, leading to higher levels of neuromodulators at synapses.
2. Is it true that LSD or acid kills off a small portion of your brain after every use? -Rhyann, NM
To my knowledge, there is no strong evidence that recreational doses of LSD kill brain cells. However, drugs do not need to act in such extreme methods to cause long-term changes in the brain. In my research, for example, I showed that brain cells activated by cocaine were more tightly connected to each other a month after a single dose of cocaine. While that is an example of how drugs can affect the physical connections between cells, drugs can also alter the strength of connections between cells. Drugs can lead to other changes in the structure of individual brain cells, and can alter the biochemical pathways within cells.
Sometimes, these long term changes are desirable. For example, when doctors prescribe antidepressants such as selective serotonin reuptake inhibitors (SSRIs), the antidepressant effects are usually not seen right away. Instead, the effects usually take 2-4 weeks to appear. Why might that be?
The immediate effects of SSRIs are to increase the concentration of the neuromodulator serotonin (see “Why does cocaine trigger the brain cell?” for how this works). This alone, however, does not appear to be sufficient to cause an antidepressant effect. One hypothesis for how SSRIs work is that the brain responds to increased serotonin levels by reducing the number of serotonin receptors over the course of days or weeks, slowly changing how brain cells respond to serotonin (see image).
However, drug use can also lead to all sorts of undesirable changes in the brain, including drug dependence and addiction. Teenaged brains are particularly susceptible to the long-term brain changes described above; the National Institute on Drug Abuse describes how “the adolescent brain is often likened to a car with a fully functioning gas pedal (the reward system) but weak brakes (the prefrontal cortex).” This is why it is important to only take the drugs prescribed by your doctor, who can monitor potential negative side effects and change your prescription to best fit your needs.
3. How can a mental illness affect the mind development? -Elias, NM
This is a fascinating question that will get you very different answers depending on who you ask. Neurobiologists tend to treat the brain and the mind as two sides of the same coin; mind development is simply the process of the brain changing over time.
Nobel Prize winner Eric Kandel states that "All mental processes are brain processes, and therefore all disorders of mental functioning are biological diseases… The brain is the organ of the mind. Where else could [mental illness] be if not in the brain?"
In this view, mental illness is physically represented in the brain, and acts alongside every other brain process to affect the process of mind development.
A mind-body dualist, however, would argue that the brain and mind are separable processes, where “mental illness” could impact development of the mind independent of physical changes in the brain. The image above is Descartes' conception of how we perceive the outside world. In his view, our eyes would see an object, that information would be transferred to the brain, and then the brain would somehow pass on this information to the "immaterial spirit", which would be where our conscious mind resides.
The mind-body dualism debate has a rich history dating back to the philosophers Plato and Aristotle, but scientists tend to find such a distinction unproductive since it separates a phenomenon from the observable, testable physical universe.
4. How does medical marijuana affect your body? -Pierrce
Preface: Possession or use of marijuana for any purpose is illegal under federal law, even though some states have decriminalized or legalized its use for medical and/or recreational purposes.
Furthermore, teenaged brains are particularly susceptible to long-term changes caused by drug use (see “Is it true that LSD or acid kills off a small portion of your brain after every use?” for more), which is one reason why states allowing recreational marijuana set a minimum age requirement of 21 years. Medical use of marijuana in minors varies by state and is heavily restricted, and must be administered by an adult caregiver.
Marijuana will act on your body the same way regardless of whether you're using it recreationally or medicinally; see the video above for a brief description. However, marijuana can act very differently depending on its chemical composition.
The active compounds in marijuana fall into a complex class of molecules called "cannabinoids", and the overall balance of cannabinoids varies widely depending on the strain. The two cannabinoids most people know of are tetrahydrocannabinol (THC) and cannabidiol (CBD).
These two molecules act very differently within the body, so medical marijuana patients will often select strains with specific concentrations of THC and CBD depending on their symptoms. The image to the left (courtesy NIDA, via Scholastic) depicts how THC can act on different brain regions to produce different effects.
According to the National Institute on Drug Abuse (NIDA), THC "can increase appetite and reduce nausea. THC may also decrease pain, inflammation (swelling and redness), and muscle control problems", whereas CBD "may be useful in reducing pain and inflammation, controlling epileptic seizures, and possibly even treating mental illness and addictions." However, few controlled clinical trials have been performed using marijuana and its cannabinoid derivatives, so these claims have been difficult to assess.
Marijuana use is also associated with a wide range of side effects including (but not limited to) impaired memory, mood changes, impaired body movement, and altered brain development. According to NIDA, the FDA approval process for marijuana itself has been slow because "researchers haven't conducted enough large-scale clinical trials that show that the benefits of the marijuana plant (as opposed to its cannabinoid ingredients) outweigh its risks in patients it's meant to treat." However, significant progress has been made toward the medical application of cannabinoids. Quoting from the National Center for Complementary and Integrative Health:
"The FDA has approved three cannabinoids as drugs. In 2018, the agency approved Epidiolex (cannabidiol or CBD) oral solution for the treatment of seizures associated with two rare, severe forms of epilepsy. This drug is derived from marijuana. The FDA has also approved the synthetic cannabinoids dronabinol and nabilone to treat nausea and vomiting associated with cancer chemotherapy in people who have already taken other medicines to treat these symptoms without good results. Dronabinol is also approved to treat loss of appetite and weight loss in people with AIDS. Dronabinol contains synthetic delta-9-tetrahydrocannabinol (THC), a component of marijuana, and nabilone contains a synthetic substance with a similar chemical structure. In 2016, the FDA approved Syndros, a liquid form of dronabinol."
Even though it might feel slow, especially for patients whose conditions might be improved with new medical advances, scientific progress does happen! Might you, the reader, be interested in joining the next generation of scientists?