When taking Human Anatomy, my favorite topic was about the nervous system. I loved learning about the different structures and what they each do. The nervous system sends signals throughout the body and controls just about everything. The most fascinating structure in the nervous system is the brain. The 3 pound structure may not look like much, but the brain is one of the most complicated structures in the body. The brain is made up of the cerebrum, cerebellum, and brainstem. Each structure has multiple functions from input of sensory information, routing that information to the right location, motor output, higher cognitive functions, and regulation of the rest of the body. Overall it’s the control center for the entire body. With the brain being such a complicated organ, there can be a lot of complications and disorders involving the brain. These disorders can be neurological (affecting motor function, psychological and/ or cognitive areas of the brain, or your emotions), those that affect how information is stored, disorders that affect the development of the body, disorders affecting the folding of the brain, or disorders that affect the person’s mood or personality. Physical trauma can also be a cause for certain disorders in the brain. The brain can also be affected by different substances like drugs.
Drugs have somewhat of a looming cloud over them by way of reputation. They’re thought of as a scary white powder that has killed people or a roll of green leaves that get people as high as a kite. That is partially true, some drugs are used to get momentary pleasure but most often lead to more harm than good. According to the National Center for Drug Abuse Statistics, around 19% of the population has used illicit drugs in 2018 and there’s been around 700,000 drug overdose deaths since 2000. But there are substances that are used to treat people with diseases. Therapeutic drugs have been used all over the world to to treat people with things ranging from neurological diseases like Alzheimer’s Disease to metabolic diseases like Zieve’s Syndrome. According to the CDC, around 46% of the population used prescription drugs from 2015-2016, with the amount of people taking them increasing as they increase with age.
If you look at the actual chemistry of drugs, it’s really interesting knowing how drugs work to effect the body. Drugs mainly impacts the brain so that’s the destination the drug needs to get to. In order to get there, it needs to go through the bloodstream and get past the Blood Brain Barrier, that has multiple receptors to allow things like carbohydrates and oxygen to get to the brain. Drugs are able to get past the Blood Brain Barrier because they can resemble chemicals that occur naturally in the body that need to get to the brain. Once they get to the brain they interfere with the synapses between neurons and the receptors on the receiving neuron. The drugs can effect the brain by either inhibit activity between neurons, such as sedatives, or they can excite the neuron and keep the neurotransmitters flowing between neurons , like antidepressents. These effects can be good in small amounts, but sustained and overusage of drugs can lead to a dependence on these effects and lead to addiction. Addiction to these drugs can change the chemistry of the brain so that you must rely on drugs in order have effects you can get without using drugs.
One of the most common brain disorders, and the one that most people think of first is Alzheimer’s Disease. The basic cause of Alzheimer’s Disease is that neurons and neuronal connections in the brain become less efficient and eventually die off. This causes brain tissue to degrade and spreads. As it spreads to the hippocampus, the main memory center of the brain, then causes the individual to lose memory, thinking skills, and other important mental functions. There is no cure for the disease but symptoms can be treated. The biggest risk factor of being diagnosed with Alzheimer’s Disease is age. The usual age of onset is around 65.
The main treatment of Alzheimer’s Disease, and practically the only treatment, is the use of acetylcholinesterase (AChE) inhibitors to stop the enzyme from breaking down the ACh used in the nerves to transport neural signals. AChE and and another enzyme are responsible for regulating the ACh levels in the synapses between neurons. These could be possible targets for the treatment of Alzheimer’s. Experiments on inhibitors such as rivastigmine, which inhibits both AChE and the other enzyme, known as butyrylcholinesterase (BuChE), indicates possible therapuetic benefits for Alzheimer’s Disease and other forms of dementia. Development of specific BuChE inhibitors along with and continued use of other cholinesterase inhibitors should lead to improved clinical outcomes.
Even though there’s no cure for Alzheimer’s, there are different treatment options in the form of drugs. One prominent option to treat Alzheimer’s are the use of inflammatory nonsteroids. Multiple studies have been found to show that these nonsteroidal treatments prevent or ameliorate symptoms of AD. There is evidence to suggest that inflammation is implicated in the pathogenesis of Alzheimer’s and this inflammation is caused by cyclooxygenases, which can be inhibited by these nonsteroidal antiinflammatory drugs. Inhibiting these cyclooxyenases will limit inflammation. Trials need to be performed to determine if these nonsteroidal antiinflammatory drugs, steroids, or both will help treat the symptoms of AD.
Drugs that are used for good can also be dangerous if used in the wrong way. One of these drugs is morphine. Morphine is a narcotic class drug that is used in most hospitals to treat severe pain. It does this by blocking pain signals from reaching the pain processing center in the brain. If given the right dosage for the concentration of morphine, this can be a drug that helps the people it’s administered to by easing their pain of what would normally be very painful. But if administered differently than prescribed or at an elevated dosage, it can become very addictive and comes with many side effects, with some of the worst including, breathing problems, cardiac arrest, and possible death. Morphine is only one example of a drug that can be either used for helping people or to hurt people, depending on how the drug is used.
Most people don’t see drug addiction as a disease, but it technically is a disease according to the Mayo Clinic. Also known as substance use disorder, like I said above, affects the brain and behavior in a way that leads to a person’s inability to control their us of a drug (legal or illegal) or medications. It changes the brain’s chemistry and physiology in a way that the person gets the need to use the drug regularly, whether it harms them or not. How it changes the chemistry is interesting to learn about. The power of addiction comes from its ability to hijack or destroy various regions of the brain that are meant to help survive. The hardwiring of your brain begins to work against you by hijacking the reward system and pleasure system of your brain. The reward system is used to seek natural rewards for things that have survival value to us. The neurotransmitter primarily used in this system is dopamine. Continued use of a drug trains the brain into thinking that the drug is necessary for survival and reduces the brain’s dopamine reduction, which leads to craving more of the drug to get more dopamine. This leads to craving and eventually independence. It can also lead to damage to the pre-frontal cortex, which is the decision making center of the brain. It disrupts the the area so that the person can’t make the decision to stop taking the drug.
Drugs aren’t the only external force that affects the brain though. Physical injury can impact the brain just about as much. Possibly, the most famous traumatic brain injury is that of Phineas Gage. While working as a railroad construction foreman in 1848, a tamping rod (measuring over 3 ft. in length and weighing 13 pounds) was driven through his head and destroyed most of the left frontal lobe of his brain. He soon made a full recovery physically, but was never fully the same. Gage’s personality was very much different than what it used to be. His behavior before the accident was respectful and likeable, but became much more erratic and irritable after. Because of this accident, we started to discover the brain’s role in determining a person’s personality.
Injuries to the brain occur to around 1.5 million Americans each year, basically all of them aren’t as severe as the Gage case. Most traumatic brain injuries nowadays are better known as concussions. Concussions occur when the brain gets jolted around inside the skull and the impacts disrupt normal brain activity. These impacts of the brain against the skull does functional damage to cognitive abilities but it is only temporary. If a person sustains multiple concussions, this could cause more permanent damage to their brain because the brain can’t return to using it’s normal pathways to function. Most concussions are now caused by sports injuries, whether headbutting a soccer ball wrong or the head gets jostled around inside of a football helmet.
The NFL has had a lot of recent cases of concussions. Retired players that had multiple concussions during their career tended to have chronic brain damage, including depression. But these effects can still be treated long after the player has retired. A new technology called resting-state network mapping has helped reveal brain networking variability between individuals and a technique called repetitive transcranial magnetic stimulation (rTMS) is believed to exert antidepressant and a personalized treatment using this technique may help individuals with a traumatic brain injury. There was a study performed using a retired defensive lineman for the NFL with neuropsychiatric disturbances. His symptoms weren’t being taken care of by conventional treatments so he was treated using multiple sessions using rTMS. The patient saw an improvement on the Montgomery-Asberg Depression Rating Scale, cognitive testing, and headache scale scores. He also saw an improvement in other aspects associated with traumatic brain injuries. This study could highlight a possibility of an individualized treatment could help individuals suffering from chronic brain trauma associated with multiple concussions.
In conclusion, the brain is one of our most important and complicated organs, yet one of the most fragile. It can be subjected to disorders, substances that alter the brain’s chemistry, and physical injury. This means we need to do our best to protect ourselves from these things. By avoiding drugs, possible injury, and keeping our brains sharp, our brain will stay healthy for as long as it possibly can.
Work Cited
Drug Addiction (Substance Use Disorder). 26 Oct. 2017, www.mayoclinic.org/diseases-conditions/drug-addiction/symptoms-causes/syc-20365112.
Greig, N. H., et al. “A New Therapeutic Target in Alzheimer's Disease Treatment: Attention to Butyrylcholinesterase.” Indiana University School of Medicine, Informa Healthcare, 16 Nov. 2015, indiana.pure.elsevier.com/en/publications/a-new-therapeutic-target-in-alzheimers-disease-treatment-attention.
“How Do Drugs Affect the Brain? - Sara Garofalo.” TED, TED-Ed, ed.ted.com/lessons/how-do-drugs-affect-the-brain-sara-garofalo.
Siddiqi, Shan H., et al. “Individualized Connectome-Targeted Transcranial Magnetic Stimulation for Neuropsychiatric Sequelae of Repetitive Traumatic Brain Injury in a Retired NFL Player.” The Journal of Neuropsychiatry and Clinical Neurosciences, The Journal of Neuropsychiatry and Clinical Neurosciences, 3 Apr. 2019, neuro.psychiatryonline.org/doi/full/10.1176/appi.neuropsych.18100230.
Substance Abuse and Addiction Statistics [2020]. 7 May 2020, drugabusestatistics.org/.
Cade-- I really enjoyed the content and flow of your paper. Like you, I also loved learning about the nervous system in Anatomy, especially getting to see the brain in lab. That opportunity really demonstrated to me how structure does reflect functional differences, like in grey versus white matter. I enjoyed your biochemical discussion about Alzheimer's disease and the drugs that show promise for its treatment. Throughout your paper I noticed several typos and grammatical errors (ex. subject verb agreement, effect versus affect). If you have time, I would review your writing before publishing which will help readers focus on your content and not the errors. Your paragraph on drug abuse was interesting. In particular, your word choice when describing addiction was great. I was unfamiliar with rTMS, but it sounds like it's a very novel and useful treatment. Overall, it was a good and interesting paper.
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